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Neder JA, Santyr G, Zanette B, Kirby M, Pourafkari M, James MD, Vincent SG, Ferguson C, Wang CY, Domnik NJ, Phillips DB, Porszasz J, Stringer WW, O'Donnell DE. Beyond Spirometry: Linking Wasted Ventilation to Exertional Dyspnea in the Initial Stages of COPD. COPD 2024; 21:2301549. [PMID: 38348843 DOI: 10.1080/15412555.2023.2301549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Accepted: 12/29/2023] [Indexed: 02/15/2024]
Abstract
Exertional dyspnea, a key complaint of patients with chronic obstructive pulmonary disease (COPD), ultimately reflects an increased inspiratory neural drive to breathe. In non-hypoxemic patients with largely preserved lung mechanics - as those in the initial stages of the disease - the heightened inspiratory neural drive is strongly associated with an exaggerated ventilatory response to metabolic demand. Several lines of evidence indicate that the so-called excess ventilation (high ventilation-CO2 output relationship) primarily reflects poor gas exchange efficiency, namely increased physiological dead space. Pulmonary function tests estimating the extension of the wasted ventilation and selected cardiopulmonary exercise testing variables can, therefore, shed unique light on the genesis of patients' out-of-proportion dyspnea. After a succinct overview of the basis of gas exchange efficiency in health and inefficiency in COPD, we discuss how wasted ventilation translates into exertional dyspnea in individual patients. We then outline what is currently known about the structural basis of wasted ventilation in "minor/trivial" COPD vis-à-vis the contribution of emphysema versus a potential impairment in lung perfusion across non-emphysematous lung. After summarizing some unanswered questions on the field, we propose that functional imaging be amalgamated with pulmonary function tests beyond spirometry to improve our understanding of this deeply neglected cause of exertional dyspnea. Advances in the field will depend on our ability to develop robust platforms for deeply phenotyping (structurally and functionally), the dyspneic patients showing unordinary high wasted ventilation despite relatively preserved FEV1.
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Affiliation(s)
- J Alberto Neder
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, Canada
| | - Giles Santyr
- Translational Medicine Department, Faculty of Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Canada
| | - Brandon Zanette
- Translational Medicine Department, Faculty of Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Canada
| | - Miranda Kirby
- Department of Physics, Faculty of Science, Toronto Metropolitan University, Toronto, Canada
| | - Marina Pourafkari
- Department of Radiology and Diagnostic Imaging, Kingston Health Sciences Centre, Kingston, Canada
| | - Matthew D James
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, Canada
| | - Sandra G Vincent
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, Canada
| | - Carrie Ferguson
- The Lundquist Institute for Biomedical Innovation, Harbor U.C.L.A Medical Centre, Torrance, CA, USA
| | - Chu-Yi Wang
- The Lundquist Institute for Biomedical Innovation, Harbor U.C.L.A Medical Centre, Torrance, CA, USA
| | - Nicolle J Domnik
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, Canada
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada
| | - Devin B Phillips
- School of Kinesiology and Health Science, York University, Toronto, Canada
| | - Janos Porszasz
- The Lundquist Institute for Biomedical Innovation, Harbor U.C.L.A Medical Centre, Torrance, CA, USA
| | - William W Stringer
- The Lundquist Institute for Biomedical Innovation, Harbor U.C.L.A Medical Centre, Torrance, CA, USA
| | - Denis E O'Donnell
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, Canada
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Diciolla NS, Rebelo P, Rodrigues G, Grave AS, Dias C, Gomes M, Santos ES, Pereira Z, Pereira L, Marques A. Validation of "CENTR(AR)" walking trails: Different field criteria do not lead to different physical activity intensities in people with COPD. Heart Lung 2024; 67:26-32. [PMID: 38640848 DOI: 10.1016/j.hrtlng.2024.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 04/10/2024] [Accepted: 04/10/2024] [Indexed: 04/21/2024]
Abstract
BACKGROUND Validating walking trails is essential to promote physical activity (PA) safely and confidently in people with COPD. OBJECTIVES We aimed to validate predetermined light, moderate, and vigorous intensities of walking trails in people with COPD. METHODS This cross-sectional study included individuals with COPD walking in predetermined light, moderate and vigorous intensity trails. Activity intensity and volume outcomes were collected. Dyspnoea and fatigue (modified Borg scale), energy expenditure (EE, Sensewear), heart rate (HR, HR monitor), time spent in different PA intensities, and cadence (ActiGraph) were recorded and used to classify PA intensity. RESULTS Twenty people with COPD [71(7) years, 80 % male, FEV1%predicted 65.6(11.6)] were included. Fatigue differed significantly between light and moderate [3.0(2.0;4.0) vs 3.4(2.5;4.5), p = 0.01], but not vigorous (3.5[2.5-4.0]) tracks. Dyspnoea [2.3(1.5) vs 2.7(1.6) vs 2.6(1.4)], EE [5.1(0.8) vs 4.9(0.5) vs 4.6(0.8) METs], HR [92.5(11.1) vs 93.7(18.6) vs 95.4(15.0) beats/min] and cadence [115.1(104.0;120.3) vs 104.7(99.6;117.6) vs 111.2(99.9;118.5) steps/min] were similar across trails (p > 0.05). Time spent in light and moderate PA, EE volume, walking time, and step count increased along with the proposed intensity levels (p < 0.01). Walking trails were categorised as moderate intensity in most participants. CONCLUSION Walking trails were safe and valid for practising moderate-intensity PA in people with COPD. Participants adjusted their physiological responses and perceived symptoms to match a moderate intensity.
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Affiliation(s)
- Nicola S Diciolla
- Physiotherapy in Women's Health Research Group - FPSM, Department of Nursing and Physiotherapy, University of Alcalá, Alcalá de Henares, Madrid, Spain; Respiratory Rehabilitation and Research Laboratory - Lab3R, School of Health Sciences (ESSUA), and Institute of Biomedicine - iBiMED, University of Aveiro, Aveiro, Portugal.
| | - Patrícia Rebelo
- Respiratory Rehabilitation and Research Laboratory - Lab3R, School of Health Sciences (ESSUA), and Institute of Biomedicine - iBiMED, University of Aveiro, Aveiro, Portugal.
| | - Guilherme Rodrigues
- Respiratory Rehabilitation and Research Laboratory - Lab3R, School of Health Sciences (ESSUA), and Institute of Biomedicine - iBiMED, University of Aveiro, Aveiro, Portugal.
| | - Ana Sofia Grave
- Respiratory Rehabilitation and Research Laboratory - Lab3R, School of Health Sciences (ESSUA), and Institute of Biomedicine - iBiMED, University of Aveiro, Aveiro, Portugal.
| | - Cíntia Dias
- Respiratory Rehabilitation and Research Laboratory - Lab3R, School of Health Sciences (ESSUA), and Institute of Biomedicine - iBiMED, University of Aveiro, Aveiro, Portugal.
| | - Maria Gomes
- Respiratory Rehabilitation and Research Laboratory - Lab3R, School of Health Sciences (ESSUA), and Institute of Biomedicine - iBiMED, University of Aveiro, Aveiro, Portugal.
| | - E Samuel Santos
- Respiratory Rehabilitation and Research Laboratory - Lab3R, School of Health Sciences (ESSUA), and Institute of Biomedicine - iBiMED, University of Aveiro, Aveiro, Portugal.
| | - Zulmira Pereira
- Cosmonível Company - Topography, Cartography and Cadaster, Porto, Portugal.
| | - Luísa Pereira
- Águeda School of Technology and Management - ESTGA, University of Aveiro, Aveiro, Portugal.
| | - Alda Marques
- Respiratory Rehabilitation and Research Laboratory - Lab3R, School of Health Sciences (ESSUA), and Institute of Biomedicine - iBiMED, University of Aveiro, Aveiro, Portugal.
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Hijleh AA, Berton DC, Neder-Serafini I, James M, Vincent S, Domnik N, Phillips D, O'Donnell DE, Neder JA. Sex- and age-adjusted reference values for dynamic inspiratory constraints during incremental cycle ergometry. Respir Physiol Neurobiol 2024; 327:104297. [PMID: 38871042 DOI: 10.1016/j.resp.2024.104297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 06/04/2024] [Accepted: 06/09/2024] [Indexed: 06/15/2024]
Abstract
Activity-related dyspnea in chronic lung disease is centrally related to dynamic (dyn) inspiratory constraints to tidal volume expansion. Lack of reference values for exertional inspiratory reserve (IR) has limited the yield of cardiopulmonary exercise testing in exposing the underpinnings of this disabling symptom. One hundred fifty apparently healthy subjects (82 males) aged 40-85 underwent incremental cycle ergometry. Based on exercise inspiratory capacity (ICdyn), we generated centile-based reference values for the following metrics of IR as a function of absolute ventilation: IRdyn1 ([1-(tidal volume/ICdyn)] x 100) and IRdyn2 ([1-(end-inspiratory lung volume/total lung capacity] x 100). IRdyn1 and IRdyn2 standards were typically lower in females and older subjects (p<0.05 for sex and age versus ventilation interactions). Low IRdyn1 and IRdyn2 significantly predicted the burden of exertional dyspnea in both sexes (p<0.01). Using these sex and age-adjusted limits of reference, the clinician can adequately judge the presence and severity of abnormally low inspiratory reserves in dyspneic subjects undergoing cardiopulmonary exercise testing.
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Affiliation(s)
- Abed A Hijleh
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University, Kingston General Hospital, Connell 2-200. 102 Stuart St., Kingston, ON K7L 2V7, Canada
| | - Danilo C Berton
- Pulmonary Function Tests Laboratory, Federal University of Rio Grande to Sul, Rua Ramiro Barcelos, 2350 Bloco A, Av. Protásio Alves, 211 - Bloco B e C - Santa Cecília, Porto Alegre, RS 90035-903, Brazil
| | - Igor Neder-Serafini
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University, Kingston General Hospital, Connell 2-200. 102 Stuart St., Kingston, ON K7L 2V7, Canada
| | - Matthew James
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University, Kingston General Hospital, Connell 2-200. 102 Stuart St., Kingston, ON K7L 2V7, Canada
| | - Sandra Vincent
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University, Kingston General Hospital, Connell 2-200. 102 Stuart St., Kingston, ON K7L 2V7, Canada
| | - Nicolle Domnik
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University, Kingston General Hospital, Connell 2-200. 102 Stuart St., Kingston, ON K7L 2V7, Canada
| | - Devin Phillips
- School of Kinesiology and Health Science, Faculty of Health, York University, Norman Bethune College, 170 Campus Walk Room 341, Toronto, ON M3J 1P3, Canada
| | - Denis E O'Donnell
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University, Kingston General Hospital, Connell 2-200. 102 Stuart St., Kingston, ON K7L 2V7, Canada
| | - J Alberto Neder
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University, Kingston General Hospital, Connell 2-200. 102 Stuart St., Kingston, ON K7L 2V7, Canada.
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Deng Z, Wu F, Wan Q, Dai C, Lu L, Peng J, Zhou K, Wu X, Tang G, Huang S, Cai G, Huang P, Wang Z, Zheng Y, Yang H, Zhao N, Xiao S, Wen X, Sun R, Yang C, Huang Y, Chen R, Zhou Y, Ran P. Clinical features and associated factors of impaired ventilatory efficiency: findings from the ECOPD study in China. BMJ Open Respir Res 2024; 11:e002320. [PMID: 39032939 PMCID: PMC11261676 DOI: 10.1136/bmjresp-2024-002320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 06/24/2024] [Indexed: 07/23/2024] Open
Abstract
BACKGROUND Impaired ventilatory efficiency during exercise is a predictor of mortality in chronic obstructive pulmonary disease. However, little is known about the clinical features and associated factors of impaired ventilatory efficiency in China. METHODS We conducted a cross-sectional community-based study in China and collected demographic and clinical information, cardiopulmonary exercise testing, spirometry, and CT data. Impaired ventilatory efficiency was defined by a nadir ventilatory equivalent for CO2 production above the upper limit of normal. Multivariable linear and logistic regression models were used to explore the clinical features and associated factors of impaired ventilatory efficiency. RESULTS The final analyses included 941 subjects, 702 (74.6%) of whom had normal ventilatory efficiency and 239 (25.4%) had impaired ventilatory efficiency. Participants with impaired ventilatory efficiency had more chronic respiratory symptoms, poorer lung function and exercise capacity, and more severe emphysema (natural logarithm transformation of the low-attenuation area of the lung with attenuation values below -950 Hounsfield units, logLAA-950: 0.19±0.65 vs -0.28±0.63, p<0.001) and air trapping (logLAA-856: 1.03±0.65 vs 0.68±0.70, p<0.001) than those with normal ventilatory efficiency. Older age (60-69 years, OR 3.10 (95% CI 1.33 to 7.21), p=0.009 and 70-80 years, OR 6.48 (95% CI 2.56 to 16.43), p<0.001 vs 40-49 years) and smoking (former, OR 3.19 (95% CI 1.29 to 7.86), p=0.012; current, OR 4.27 (95% CI 1.78 to 10.24), p=0.001 vs never) were identified as high risk factors of impaired ventilatory efficiency. CONCLUSIONS Impaired ventilatory efficiency was associated with poorer respiratory characteristics. Longitudinal studies are warranted to explore the progression of individuals with impaired ventilatory efficiency.
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Affiliation(s)
- Zhishan Deng
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Fan Wu
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou National Laboratory, Guangzhou, Guangdong, China
| | - Qi Wan
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Cuiqiong Dai
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Lifei Lu
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Jieqi Peng
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou National Laboratory, Guangzhou, Guangdong, China
| | - Kunning Zhou
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Xiaohui Wu
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou National Laboratory, Guangzhou, Guangdong, China
| | - Gaoying Tang
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Suyin Huang
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou National Laboratory, Guangzhou, Guangdong, China
| | - Guannan Cai
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Peiyu Huang
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Zihui Wang
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Youlan Zheng
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Huajing Yang
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Ningning Zhao
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Shan Xiao
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Xiang Wen
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Ruiting Sun
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Changli Yang
- Department of Pulmonary and Critical Care Medicine, Wengyuan County People’s Hospital, Shaoguan, Guangdong, China
| | - Yongqing Huang
- Lianping County People’s Hospital, Heyuan, Guangdong, China
| | - Rongchang Chen
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Yumin Zhou
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou National Laboratory, Guangzhou, Guangdong, China
| | - Pixin Ran
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & Guangzhou Institute of Respiratory Health & National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China
- Guangzhou National Laboratory, Guangzhou, Guangdong, China
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Tang CY, Bernstein B, Blackstock F, Blondeel A, Gershon A, Gimeno-Santos E, Gloeckl R, Marques A, Spruit MA, Garvey C, Morgan M, Nici L, Singh SJ, Troosters T. Unravelling the complex interplay of factors behind exercise limitations and physical inactivity in COPD. Breathe (Sheff) 2024; 20:230180. [PMID: 38873234 PMCID: PMC11167652 DOI: 10.1183/20734735.0180-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 04/28/2024] [Indexed: 06/15/2024] Open
Abstract
Exercise limitation and physical inactivity are known treatable traits for people with COPD. Maximising exercise capacity and keeping people physically active improves health status and survival rates among people with COPD. However, managing these two treatable traits can be extremely challenging for clinicians due to the complex intersectionality of factors influencing an individual's capacity, opportunity and motivation to engage in physical activity. This review presents the complex factors influencing exercise capacity ("can do"), levels of physical activity ("do do") and sedentary behaviours amongst people with COPD and provides practical recommendations on how clinicians can address some of these factors in practice. Most importantly, it highlights the importance of referring to pulmonary rehabilitation as a way to improve exercise capacity among people with COPD.
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Affiliation(s)
- Clarice Y. Tang
- Institute of Health, Exercise and Science, Victoria University, Melbourne, Australia
- School of Health Sciences, Western Sydney University, Sydney, Australia
| | - Bruce Bernstein
- Research Development, Saint Francis Hospital and Medical Center, Hartford, CT, USA
- Drexel University College of Medicine, Philadelphia, PA, USA
| | - Felicity Blackstock
- School of Health Sciences, Western Sydney University, Sydney, Australia
- Office of the Deputy Vice Chancellor (Education), University of Sydney, Sydney, Australia
| | - Astrid Blondeel
- Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium
| | - Andrea Gershon
- Division of Respirology, Sunnybrook Health Sciences Centre, Sunnybrook Research Institute and ICES, University of Toronto, Toronto, ON, Canada
| | - Elena Gimeno-Santos
- Barcelona of Global Health Institute (ISGlobal) - Universitat Pompeu Fabra (UPF), Barcelona, Spain
- Hospital Clinic of Barcelona – August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
- CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Rainer Gloeckl
- Institute for Pulmonary Rehabilitation Research, Schön Klinik Berchtesgadener Land, Schönau am Königssee, Germany
| | - Alda Marques
- Lab3R – Respiratory Research and Rehabilitation Laboratory, School of Health Sciences (ESSUA) and Institute of Biomedicine (iBiMED), University of Aveiro, Aveiro, Portugal
| | - Martijn A. Spruit
- Department of Research and Development, CIRO, Horn, The Netherlands
- Department of Respiratory Medicine, Maastricht University Medical Centre (MUMC+) NUTRIM School of Nutrition and Translational Research in Metabolism, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Chris Garvey
- Retired, University of California, San Francisco, CA, USA
| | - Mike Morgan
- Retired, Department of Respiratory Sciences, University of Leicester, Biomedical Research Centre, Leicester, UK
| | - Linda Nici
- Providence Veterans Affairs Medical Center, Providence, RI, USA
- The Warren Alpert Medical School, Brown University, Providence, RI, USA
| | - Sally J. Singh
- Department of Respiratory Sciences, University of Leicester, Biomedical Research Centre, Leicester, UK
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Panza L, Piamonti D, Palange P. Pulmonary gas exchange and ventilatory efficiency during exercise in health and diseases. Expert Rev Respir Med 2024; 18:355-367. [PMID: 38912849 DOI: 10.1080/17476348.2024.2370447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 06/17/2024] [Indexed: 06/25/2024]
Abstract
INTRODUCTION Cardiopulmonary exercise testing (CPET) is nowadays used to study the exercise response in healthy subjects and in disease. Ventilatory efficiency is one of the main determinants in exercise tolerance, and its main variables are a useful tool to guide pathophysiologists toward specific diagnostic pathways, providing prognostic information and improving disease management, treatment, and outcomes. AREAS COVERED This review will be based on today's available scientific evidence, describing the main physiological determinants of ventilatory efficiency at rest and during exercise, and focusing also on how CPET variables are modified in specific diseases, leading to the possibility of early diagnosis and management. EXPERT OPINION Growing knowledge on CPET interpretation and a wider use of this clinical tool is expected in order to offer more precise diagnostic and prognostic information to patients and clinicians, helping in the management of therapeutic decisions. Future research could be able to identify new and more simple markers of ventilatory efficiency, and to individuate new interventions for the improvement of symptoms, such as exertional dyspnea.
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Affiliation(s)
- Luigi Panza
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Daniel Piamonti
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Paolo Palange
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
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Phillips DB, James MD, Vincent SG, Elbehairy AF, Neder JA, Kirby M, Ora J, Day AG, Tan WC, Bourbeau J, O'Donnell DE. Physiological Characterization of Preserved Ratio Impaired Spirometry in the CanCOLD Study: Implications for Exertional Dyspnea and Exercise Intolerance. Am J Respir Crit Care Med 2024; 209:1314-1327. [PMID: 38170674 DOI: 10.1164/rccm.202307-1184oc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 01/03/2024] [Indexed: 01/05/2024] Open
Abstract
Rationale: It is increasingly recognized that adults with preserved ratio impaired spirometry (PRISm) are prone to increased morbidity. However, the underlying pathophysiological mechanisms are unknown. Objectives: Evaluate the mechanisms of increased dyspnea and reduced exercise capacity in PRISm. Methods: We completed a cross-sectional analysis of the CanCOLD (Canadian Cohort Obstructive Lung Disease) population-based study. We compared physiological responses in 59 participants meeting PRISm spirometric criteria (post-bronchodilator FEV1 < 80% predicted and FEV1/FVC ⩾ 0.7), 264 control participants, and 170 ever-smokers with chronic obstructive pulmonary disease (COPD), at rest and during cardiopulmonary exercise testing. Measurements and Main Results: Individuals with PRISm had lower total lung, vital, and inspiratory capacities than healthy controls (all P < 0.05) and minimal small airway, pulmonary gas exchange, and radiographic parenchymal lung abnormalities. Compared with healthy controls, individuals with PRISm had higher dyspnea/[Formula: see text]o2 ratio at peak exercise (4.0 ± 2.2 vs. 2.9 ± 1.9 Borg units/L/min; P < 0.001) and lower [Formula: see text]o2peak (74 ± 22% predicted vs. 96 ± 25% predicted; P < 0.001). At standardized submaximal work rates, individuals with PRISm had greater Vt/inspiratory capacity (Vt%IC; P < 0.001), reflecting inspiratory mechanical constraint. In contrast to participants with PRISm, those with COPD had characteristic small airways dysfunction, dynamic hyperinflation, and pulmonary gas exchange abnormalities. Despite these physiological differences among the three groups, the relationship between increasing dyspnea and Vt%IC during cardiopulmonary exercise testing was similar. Resting IC significantly correlated with [Formula: see text]o2peak (r = 0.65; P < 0.001) in the entire sample, even after adjusting for airflow limitation, gas trapping, and diffusing capacity. Conclusions: In individuals with PRISm, lower exercise capacity and higher exertional dyspnea than healthy controls were mainly explained by lower resting lung volumes and earlier onset of dynamic inspiratory mechanical constraints at relatively low work rates. Clinical trial registered with www.clinicaltrials.gov (NCT00920348).
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Affiliation(s)
- Devin B Phillips
- School of Kinesiology and Health Science, Faculty of Health, and
- Muscle Health Research Center, York University, Toronto, Ontario, Canada
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre Kingston General Hospital Site, Kingston, Ontario, Canada
| | - Matthew D James
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre Kingston General Hospital Site, Kingston, Ontario, Canada
| | - Sandra G Vincent
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre Kingston General Hospital Site, Kingston, Ontario, Canada
| | - Amany F Elbehairy
- Department of Chest Diseases, Faculty of Medicine, Alexandria University, Alexandria, Egypt
- Division of Infection, Immunity, and Respiratory Medicine, The University of Manchester, and Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - J Alberto Neder
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre Kingston General Hospital Site, Kingston, Ontario, Canada
| | - Miranda Kirby
- Department of Physics, Toronto Metropolitan University, Toronto, Ontario, Canada
| | - Josuel Ora
- Division of Respiratory Medicine, University Hospital Policlinico Tor Vergata, Rome, Italy
| | - Andrew G Day
- Kingston General Hospital Research Institute, Kingston, Ontario, Canada
| | - Wan C Tan
- Centre for Heart Lung Innovation, Providence Health Care Research Institute, University of British Columbia, St. Paul's Hospital, Vancouver, British Columbia, Canada; and
| | - Jean Bourbeau
- Research Institute of the McGill University Health Centre, Translational Research in Respiratory Diseases Program and Respiratory Epidemiology and Clinical Research Unit, and
- Division of Respiratory Medicine, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada
| | - Denis E O'Donnell
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre Kingston General Hospital Site, Kingston, Ontario, Canada
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8
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Wang K, Wu F, He H, Hu C, Chen X, Chen J, Cao W, Liu J, Zhao J, Zhao Z, Zhao Z. Association between computed tomography-quantified respiratory muscles and chronic obstructive pulmonary disease: a retrospective study. BMC Pulm Med 2024; 24:150. [PMID: 38515154 PMCID: PMC10956391 DOI: 10.1186/s12890-024-02955-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 03/07/2024] [Indexed: 03/23/2024] Open
Abstract
BACKGROUND This study examined the association between chest muscles and chronic obstructive pulmonary disease (COPD) and the relationship between chest muscle areas and acute exacerbations of COPD (AECOPD). METHODS There were 168 subjects in the non-COPD group and 101 patients in the COPD group. The respiratory and accessory respiratory muscle areas were obtained using 3D Slicer software to analysis the imaging of computed tomography (CT). Univariate and multivariate Poisson regressions were used to analyze the number of AECOPD cases during the preceding year. The cutoff value was obtained using a receiver operating characteristic (ROC) curve. RESULTS We scanned 6342 subjects records, 269 of which were included in this study. We then measured the following muscle areas (non-COPD group vs. COPD group): pectoralis major (19.06 ± 5.36 cm2 vs. 13.25 ± 3.71 cm2, P < 0.001), pectoralis minor (6.81 ± 2.03 cm2 vs. 5.95 ± 1.81 cm2, P = 0.001), diaphragmatic dome (1.39 ± 0.97 cm2 vs. 0.85 ± 0.72 cm2, P = 0.011), musculus serratus anterior (28.03 ± 14.95 cm2 vs.16.76 ± 12.69 cm2, P < 0.001), intercostal muscle (12.36 ± 6.64 cm2 vs. 7.15 ± 5.6 cm2, P < 0.001), pectoralis subcutaneous fat (25.91 ± 13.23 cm2 vs. 18.79 ± 10.81 cm2, P < 0.001), paravertebral muscle (14.8 ± 4.35 cm2 vs. 13.33 ± 4.27 cm2, P = 0.007), and paravertebral subcutaneous fat (12.57 ± 5.09 cm2 vs. 10.14 ± 6.94 cm2, P = 0.001). The areas under the ROC curve for the pectoralis major, intercostal, and the musculus serratus anterior muscle areas were 81.56%, 73.28%, and 71.56%, respectively. Pectoralis major area was negatively associated with the number of AECOPD during the preceding year after adjustment (relative risk, 0.936; 95% confidence interval, 0.879-0.996; P = 0.037). CONCLUSION The pectoralis major muscle area was negative associated with COPD. Moreover, there was a negative correlation between the number of AECOPD during the preceding year and the pectoralis major area.
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Affiliation(s)
- Ke Wang
- Department of Infectious Diseases, Respiratory and Critical Care Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
- Guangzhou Chest Hospital, Guangzhou, China
| | - Fan Wu
- State Key Laboratory of Respiratory Disease & National Clinical Research Center for Respiratory Disease & National Center for Respiratory Medicine & Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou National Laboratory, Guangzhou, China
| | - Hua He
- Department of Infectious Diseases, Respiratory and Critical Care Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Chengyi Hu
- Department of Infectious Diseases, Respiratory and Critical Care Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Xiaobang Chen
- Department of Infectious Diseases, Respiratory and Critical Care Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Jinglong Chen
- Department of Geriatrics, National Clinical Key Specialty, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Weitao Cao
- Department of Infectious Diseases, Respiratory and Critical Care Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Jun Liu
- Department of Infectious Diseases, Respiratory and Critical Care Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | | | - Ziwen Zhao
- Department of Infectious Diseases, Respiratory and Critical Care Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Zhuxiang Zhao
- Department of Infectious Diseases, Respiratory and Critical Care Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China.
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9
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Milne KM, Mitchell RA, Ferguson ON, Hind AS, Guenette JA. Sex-differences in COPD: from biological mechanisms to therapeutic considerations. Front Med (Lausanne) 2024; 11:1289259. [PMID: 38572156 PMCID: PMC10989064 DOI: 10.3389/fmed.2024.1289259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 02/29/2024] [Indexed: 04/05/2024] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a heterogeneous respiratory condition characterized by symptoms of dyspnea, cough, and sputum production. We review sex-differences in disease mechanisms, structure-function-symptom relationships, responses to therapies, and clinical outcomes in COPD with a specific focus on dyspnea. Females with COPD experience greater dyspnea and higher morbidity compared to males. Imaging studies using chest computed tomography scans have demonstrated that females with COPD tend to have smaller airways than males as well as a lower burden of emphysema. Sex-differences in lung and airway structure lead to critical respiratory mechanical constraints during exercise at a lower absolute ventilation in females compared to males, which is largely explained by sex differences in maximum ventilatory capacity. Females experience similar benefit with respect to inhaled COPD therapies, pulmonary rehabilitation, and smoking cessation compared to males. Ongoing re-assessment of potential sex-differences in COPD may offer insights into the evolution of patterns of care and clinical outcomes in COPD patients over time.
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Affiliation(s)
- Kathryn M. Milne
- Centre for Heart Lung Innovation, The University of British Columbia and Providence Research, St. Paul’s Hospital, Vancouver, BC, Canada
- Division of Respiratory Medicine, The University of British Columbia, Vancouver, BC, Canada
| | - Reid A. Mitchell
- Centre for Heart Lung Innovation, The University of British Columbia and Providence Research, St. Paul’s Hospital, Vancouver, BC, Canada
| | - Olivia N. Ferguson
- Centre for Heart Lung Innovation, The University of British Columbia and Providence Research, St. Paul’s Hospital, Vancouver, BC, Canada
| | - Alanna S. Hind
- Centre for Heart Lung Innovation, The University of British Columbia and Providence Research, St. Paul’s Hospital, Vancouver, BC, Canada
| | - Jordan A. Guenette
- Centre for Heart Lung Innovation, The University of British Columbia and Providence Research, St. Paul’s Hospital, Vancouver, BC, Canada
- Division of Respiratory Medicine, The University of British Columbia, Vancouver, BC, Canada
- Department of Physical Therapy, The University of British Columbia, Vancouver, BC, Canada
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10
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Brotto AR, Phillips DB, Rowland SD, Moore LE, Wong E, Stickland MK. Reduced tidal volume-inflection point and elevated operating lung volumes during exercise in females with well-controlled asthma. BMJ Open Respir Res 2023; 10:e001791. [PMID: 38135461 DOI: 10.1136/bmjresp-2023-001791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 12/01/2023] [Indexed: 12/24/2023] Open
Abstract
INTRODUCTION Individuals with asthma breathe at higher operating lung volumes during exercise compared with healthy individuals, which contributes to increased exertional dyspnoea. In health, females are more likely to develop exertional dyspnoea than males at a given workload or ventilation, and therefore, it is possible that females with asthma may develop disproportional dyspnoea on exertion. The purpose of this study was to compare operating lung volume and dyspnoea responses during exercise in females with and without asthma. METHODS Sixteen female controls and 16 females with asthma were recruited for the study along with 16 male controls and 16 males with asthma as a comparison group. Asthma was confirmed using American Thoracic Society criteria. Participants completed a cycle ergometry cardiopulmonary exercise test to volitional exhaustion. Inspiratory capacity manoeuvres were performed to estimate inspiratory reserve volume (IRV) and dyspnoea was evaluated using the Modified Borg Scale. RESULTS Females with asthma exhibited elevated dyspnoea during submaximal exercise compared with female controls (p<0.05). Females with asthma obtained a similar IRV and dyspnoea at peak exercise compared with healthy females despite lower ventilatory demand, suggesting mechanical constraint to tidal volume (VT) expansion. VT-inflection point was observed at significantly lower ventilation and V̇O2 in females with asthma compared with female controls. Forced expired volume in 1 s was significantly associated with VT-inflection point in females with asthma (R2=0.401; p<0.01) but not female controls (R2=0.002; p=0.88). CONCLUSION These results suggest that females with asthma are more prone to experience exertional dyspnoea, secondary to dynamic mechanical constraints during submaximal exercise when compared with females without asthma.
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Affiliation(s)
- Andrew R Brotto
- Pulmonary Division, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Devin B Phillips
- Pulmonary Division, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
- School of Kinesiology and Health Science, Faculty of Health, York University, Toronto, Ontario, Canada
| | - Samira D Rowland
- Pulmonary Division, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Linn E Moore
- Pulmonary Division, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Eric Wong
- Pulmonary Division, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Michael K Stickland
- Pulmonary Division, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
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11
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Behnia M, Sietsema KE. Utility of Cardiopulmonary Exercise Testing in Chronic Obstructive Pulmonary Disease: A Review. Int J Chron Obstruct Pulmon Dis 2023; 18:2895-2910. [PMID: 38089541 PMCID: PMC10710955 DOI: 10.2147/copd.s432841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 10/17/2023] [Indexed: 12/18/2023] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a disease defined by airflow obstruction with a high morbidity and mortality and significant economic burden. Although pulmonary function testing is the cornerstone in diagnosis of COPD, it cannot fully characterize disease severity or cause of dyspnea because of disease heterogeneity and variable related and comorbid conditions affecting cardiac, vascular, and musculoskeletal systems. Cardiopulmonary exercise testing (CPET) is a valuable tool for assessing physical function in a wide range of clinical conditions, including COPD. Familiarity with measurements made during CPET and its potential to aid in clinical decision-making related to COPD can thus be useful to clinicians caring for this population. This review highlights pulmonary and extrapulmonary impairments that can contribute to exercise limitation in COPD. Key elements of CPET are identified with an emphasis on measurements most relevant to COPD. Finally, clinical applications of CPET demonstrated to be of value in the COPD setting are identified. These include quantifying functional capacity, differentiating among potential causes of symptoms and limitation, prognostication and risk assessment for operative procedures, and guiding exercise prescription.
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Affiliation(s)
- Mehrdad Behnia
- Pulmonary and Critical Care, University of Central Florida, Orlando, FL, USA
| | - Kathy E Sietsema
- The Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA, USA
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12
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Cross TJ, Isautier JMJ, Kelley EF, Hubbard CD, Morris SJ, Smith JR, Duke JW. A Systematic Review of Methods Used to Determine the Work of Breathing during Exercise. Med Sci Sports Exerc 2023; 55:1672-1682. [PMID: 37126027 DOI: 10.1249/mss.0000000000003187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
INTRODUCTION Measurement of the work of breathing (Wb) during exercise provides useful insights into the energetics and mechanics of the respiratory muscles across a wide range of minute ventilations. The methods and analytical procedures used to calculate the Wb during exercise have yet to be critically appraised in the literature. PURPOSE The aim of this systematic review was to evaluate the quality of methods used to measure the Wb during exercise in the available literature. METHODS We conducted an extensive search of three databases for studies that measured the Wb during exercise in adult humans. Data were extracted on participant characteristics, flow/volume and pressure devices, esophageal pressure (P oes ) catheters, and methods of Wb analysis. RESULTS A total of 120 articles were included. Flow/volume sensors used were primarily pneumotachographs ( n = 85, 70.8%), whereas the most common pressure transducer was of the variable reluctance type ( n = 63, 52.5%). Esophageal pressure was frequently obtained via balloon-tipped catheters ( n = 114, 95.0%). Few studies mentioned calibration, frequency responses, and dynamic compensation of their measurement devices. The most popular method of measuring the Wb was pressure-volume integration ( n = 51, 42.5%), followed by the modified Campbell ( n = 28, 23.3%) and Dean & Visscher diagrams ( n = 26, 21.7%). Over one-third of studies did not report the methods used to process their pressure-volume data, and the majority (60.8%) of studies used the incorrect Wb units and/or failed to discuss the limitations of their Wb measurements. CONCLUSIONS The findings of this systematic review highlight the need for the development of a standardized approach for measuring Wb, which is informative, practical, and accessible for future researchers.
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Affiliation(s)
- Troy J Cross
- Faculty of Medicine and Health, University of Sydney, NSW, AUSTRALIA
| | | | - Eli F Kelley
- Air Force Research Laboratory, 711HPW/RHBFP, Wright-Patterson Air Force Base, OH
| | - Colin D Hubbard
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ
| | - Sarah J Morris
- Faculty of Medicine and Health, University of Sydney, NSW, AUSTRALIA
| | - Joshua R Smith
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN
| | - Joseph W Duke
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ
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13
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MacAskill W, Hoffman B, Johnson MA, Sharpe GR, Rands J, Wotherspoon SE, Gevorkov Y, Kolbe‐Alexander TL, Mills DE. The effects of age on dyspnea and respiratory mechanical and neural responses to exercise in healthy men. Physiol Rep 2023; 11:e15794. [PMID: 37604647 PMCID: PMC10442526 DOI: 10.14814/phy2.15794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 08/02/2023] [Accepted: 08/02/2023] [Indexed: 08/23/2023] Open
Abstract
The respiratory muscle pressure generation and inspiratory and expiratory neuromuscular recruitment patterns in younger and older men were compared during exercise, alongside descriptors of dyspnea. Healthy younger (n = 8, 28 ± 5 years) and older (n = 8, 68 ± 4 years) men completed a maximal incremental cycling test. Esophageal, gastric (Pga ) and transdiaphragmatic pressures, and electromyography (EMG) of the crural diaphragm were measured using a micro-transducer and EMG catheter. EMG of the parasternal intercostals, sternocleidomastoids, and rectus abdominis were measured using skin surface electrodes. After the exercise test, participants completed a questionnaire to evaluate descriptors of dyspnea. Pga at end-expiration, Pga expiratory tidal swings, and the gastric pressure-time product (PTPga ) at absolute and relative minute ventilation were higher (p < 0.05) for older compared to younger men. There were no differences in EMG responses between older and younger men. Younger men were more likely to report shallow breathing (p = 0.005) than older men. Our findings showed younger and older men had similar respiratory neuromuscular activation patterns and reported different dyspnea descriptors, and that older men had greater expiratory muscle pressure generation during exercise. Greater expiratory muscle pressures in older men may be due to compensatory mechanisms designed to offset increasing airway resistance due to aging. These results may have implications for exercise-induced expiratory muscle fatigue in older men.
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Affiliation(s)
- William MacAskill
- School of Health and Medical SciencesUniversity of Southern QueenslandIpswichQueenslandAustralia
- Respiratory and Exercise Physiology Research Group, School of Health and WellbeingUniversity of Southern QueenslandIpswichQueenslandAustralia
- Centre for Health ResearchInstitute for Resilient Regions, University of Southern QueenslandIpswichQueenslandAustralia
- Rural Clinical SchoolGriffith UniversityToowoombaQueenslandAustralia
| | - Ben Hoffman
- School of Health and Medical SciencesUniversity of Southern QueenslandIpswichQueenslandAustralia
- Centre for Health ResearchInstitute for Resilient Regions, University of Southern QueenslandIpswichQueenslandAustralia
| | - Michael A. Johnson
- Exercise and Health Research Group, Sport, Health and Performance Enhancement (SHAPE) Research Centre, School of Science and TechnologyNottingham Trent UniversityNottinghamshireUK
| | - Graham R. Sharpe
- Exercise and Health Research Group, Sport, Health and Performance Enhancement (SHAPE) Research Centre, School of Science and TechnologyNottingham Trent UniversityNottinghamshireUK
| | - Joshua Rands
- School of Health and Medical SciencesUniversity of Southern QueenslandIpswichQueenslandAustralia
- Respiratory and Exercise Physiology Research Group, School of Health and WellbeingUniversity of Southern QueenslandIpswichQueenslandAustralia
| | | | - Yaroslav Gevorkov
- Institute of Vision Systems, Hamburg University of TechnologyHamburgGermany
| | - Tracy L. Kolbe‐Alexander
- School of Health and Medical SciencesUniversity of Southern QueenslandIpswichQueenslandAustralia
- Centre for Health ResearchInstitute for Resilient Regions, University of Southern QueenslandIpswichQueenslandAustralia
- UCT Research Centre for Health through Physical Activity, Lifestyle and Sport (HPALS), Division of Research Unit for Exercise Science and Sports Medicine, Faculty of Health SciencesUniversity of Cape TownCape TownSouth Africa
| | - Dean E. Mills
- School of Health and Medical SciencesUniversity of Southern QueenslandIpswichQueenslandAustralia
- Respiratory and Exercise Physiology Research Group, School of Health and WellbeingUniversity of Southern QueenslandIpswichQueenslandAustralia
- Centre for Health ResearchInstitute for Resilient Regions, University of Southern QueenslandIpswichQueenslandAustralia
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14
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Guenette JA, Milne KM, O'Donnell DE. The Lancet COPD Commission: broader questions remain. Lancet 2023; 401:1568-1569. [PMID: 37179112 DOI: 10.1016/s0140-6736(23)00555-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 03/12/2023] [Indexed: 05/15/2023]
Affiliation(s)
- Jordan A Guenette
- Centre for Heart Lung Innovation, Providence Research, The University of British Columbia and St Paul's Hospital, Vancouver, BC V6Z 1Y6, Canada; Department of Physical Therapy, The University of British Columbia, Vancouver, Canada; Division of Respiratory Medicine, The University of British Columbia, Gordon and Leslie Diamond Health Care Centre, Vancouver, Canada.
| | - Kathryn M Milne
- Centre for Heart Lung Innovation, Providence Research, The University of British Columbia and St Paul's Hospital, Vancouver, BC V6Z 1Y6, Canada; Division of Respiratory Medicine, The University of British Columbia, Gordon and Leslie Diamond Health Care Centre, Vancouver, Canada
| | - Denis E O'Donnell
- Respiratory Investigation Unit, Queen's University and Kingston General Hospital, Kingston, ON, Canada
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15
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Nicolò A, Sacchetti M. Differential control of respiratory frequency and tidal volume during exercise. Eur J Appl Physiol 2023; 123:215-242. [PMID: 36326866 DOI: 10.1007/s00421-022-05077-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 10/18/2022] [Indexed: 11/06/2022]
Abstract
The lack of a testable model explaining how ventilation is regulated in different exercise conditions has been repeatedly acknowledged in the field of exercise physiology. Yet, this issue contrasts with the abundance of insightful findings produced over the last century and calls for the adoption of new integrative perspectives. In this review, we provide a methodological approach supporting the importance of producing a set of evidence by evaluating different studies together-especially those conducted in 'real' exercise conditions-instead of single studies separately. We show how the collective assessment of findings from three domains and three levels of observation support the development of a simple model of ventilatory control which proves to be effective in different exercise protocols, populations and experimental interventions. The main feature of the model is the differential control of respiratory frequency (fR) and tidal volume (VT); fR is primarily modulated by central command (especially during high-intensity exercise) and muscle afferent feedback (especially during moderate exercise) whereas VT by metabolic inputs. Furthermore, VT appears to be fine-tuned based on fR levels to match alveolar ventilation with metabolic requirements in different intensity domains, and even at a breath-by-breath level. This model reconciles the classical neuro-humoral theory with apparently contrasting findings by leveraging on the emerging control properties of the behavioural (i.e. fR) and metabolic (i.e. VT) components of minute ventilation. The integrative approach presented is expected to help in the design and interpretation of future studies on the control of fR and VT during exercise.
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Affiliation(s)
- Andrea Nicolò
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Piazza Lauro De Bosis 6, 00135, Rome, Italy.
| | - Massimo Sacchetti
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Piazza Lauro De Bosis 6, 00135, Rome, Italy
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16
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Phillips DB, James MD, O'Donnell CJD, Vincent SG, Webb KA, de-Torres JP, Neder JA, O'Donnell DE. Physiological Predictors of Morbidity and Mortality in COPD: The Relative Importance of Reduced Inspiratory Capacity and Inspiratory Muscle Strength. J Appl Physiol (1985) 2022; 133:679-688. [PMID: 35952349 DOI: 10.1152/japplphysiol.00352.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Low resting inspiratory capacity (IC) and low maximal inspiratory pressure (MIP) have previously been linked to exertional dyspnea, exercise limitation and poor survival in chronic obstructive pulmonary disease (COPD). The interaction and relative contributions of these two related variables to important clinical outcomes are unknown. The objective of the current study was to examine the interaction between resting IC and MIP (both % predicted), exertional dyspnea, exercise capacity and long-term survival in patients with COPD. Two hundred and eighty-five patients with mild to advanced COPD completed standard lung function testing and a cycle cardiopulmonary exercise test. Multiple regression determined predictors of the exertional dyspnea-ventilation slope and peak oxygen uptake (V̇O2peak). Cox regression determined predictors of 10-year mortality. IC was associated with the dyspnea-ventilation slope (standardized β=-0.44, p<0.001), while MIP was excluded from the regression model (p=0.713). IC and MIP were included in the final model to predict V̇O2peak. However, the standardized β was greater for IC (0.49) than MIP (0.22). After adjusting for age, sex, body mass index, cardiovascular risk, airflow obstruction and diffusing capacity, resting IC was independently associated with 10-year all-cause mortality (hazard ratio=1.25, confidence interval5-95%=1.16-1.34, p<0.001), while MIP was excluded from the final model (all p=0.829). Low resting IC was consistently linked to heightened dyspnea intensity, low V̇O2peak and worse survival in COPD even after accounting for airway obstruction, inspiratory muscle strength, and diffusing capacity. These results support the use of resting IC as an important physiological biomarker closely linked to key clinical outcomes in COPD.
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Affiliation(s)
- Devin B Phillips
- Respiratory Investigation Unit, Department of Medicine and Queen's University and Kingston Health Sciences Centre, Kingston, Ontario, Canada
| | - Matthew D James
- Respiratory Investigation Unit, Department of Medicine and Queen's University and Kingston Health Sciences Centre, Kingston, Ontario, Canada
| | - Conor J D O'Donnell
- Respiratory Investigation Unit, Department of Medicine and Queen's University and Kingston Health Sciences Centre, Kingston, Ontario, Canada
| | - Sandra G Vincent
- Respiratory Investigation Unit, Department of Medicine and Queen's University and Kingston Health Sciences Centre, Kingston, Ontario, Canada
| | - Katherine A Webb
- Respiratory Investigation Unit, Department of Medicine and Queen's University and Kingston Health Sciences Centre, Kingston, Ontario, Canada
| | - Juan Pablo de-Torres
- Respiratory Investigation Unit, Department of Medicine and Queen's University and Kingston Health Sciences Centre, Kingston, Ontario, Canada
| | - J Alberto Neder
- Respiratory Investigation Unit, Department of Medicine and Queen's University and Kingston Health Sciences Centre, Kingston, Ontario, Canada
| | - Denis E O'Donnell
- Respiratory Investigation Unit, Department of Medicine and Queen's University and Kingston Health Sciences Centre, Kingston, Ontario, Canada
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17
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James MD, Phillips DB, Vincent SG, Abdallah SJ, Donovan AA, de-Torres JP, Neder JA, Smith BM, Jensen D, O'Donnell DE. Exertional dyspnoea in patients with mild-to-severe chronic obstructive pulmonary disease (COPD): Neuromechanical mechanisms. J Physiol 2022; 600:4227-4245. [PMID: 35861594 DOI: 10.1113/jp283252] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 07/11/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Dyspnoea during exercise is a common and troublesome symptom reported by patients with chronic obstructive pulmonary disease (COPD) and is linked to an elevated inspiratory neural drive (IND). The precise mechanisms of elevated IND and dyspnoea across the continuum of airflow obstruction severity in COPD remains unclear. The present study sought to determine the mechanisms of elevated IND [by diaphragm EMG, EMGdi (%max)] and dyspnoea during cardiopulmonary exercise testing (CPET) across the continuum of COPD severity. There was a strong association between increasing dyspnoea intensity and EMGdi (%max) during CPET across the COPD continuum despite significant heterogeneity in underlying pulmonary gas exchange and respiratory mechanical impairments. Critical inspiratory constraints occurred at progressively lower ventilation during exercise with worsening severity of COPD. This was associated with the progressively lower resting inspiratory capacity with worsening disease severity. Earlier critical inspiratory constraint was associated with earlier neuromechanical dissociation and greater likelihood of reporting the sensation of 'unsatisfied inspiration'. ABSTRACT In patients with COPD, exertional dyspnoea generally arises when there is imbalance between ventilatory demand and capacity, but the neurophysiological mechanisms are unclear. We therefore determined if disparity between elevated inspiratory neural drive (IND) and tidal volume (VT ) responses (neuromechanical dissociation) impacted dyspnoea intensity and quality during exercise, across the COPD severity spectrum. In this two-centre, cross-sectional observational study, 89 participants with COPD divided into tertiles of FEV1 %predicted (Tertile 1 = FEV1 = 87 ± 9%, Tertile 2 = 60 ± 9%, Tertile 3 = 32 ± 8%) and 18 non-smoking controls, completed a symptom-limited cardiopulmonary exercise tests (CPET) with measurement of IND by diaphragm electromyography [EMGdi (%max)]. The association between increasing dyspnoea intensity and EMGdi (%max) during CPET was strong (r = 0.730, P < 0.001) and not different between the four groups who showed marked heterogeneity in pulmonary gas exchange and mechanical abnormalities. Significant inspiratory constraints (tidal volume/inspiratory capacity (VT /IC) ≥ 70%) and onset of neuromechanical dissociation (EMGdi (%max):VT /IC > 0.75) occurred at progressively lower V̇E from Control to Tertile 3. Lower resting IC meant earlier onset of neuromechanical dissociation, heightened dyspnoea intensity and greater propensity (93% in Tertile 3) to select qualitative descriptors of 'unsatisfied inspiration'. We concluded that, regardless of marked variation in mechanical and pulmonary gas exchange abnormalities in our study sample, exertional dyspnoea intensity was linked to the magnitude of EMGdi (%max). Moreover, onset of critical inspiratory constraints and attendant neuromechanical dissociation amplified dyspnoea intensity at higher exercise intensities. Simple measurements of IC and breathing pattern during CPET provide useful insights into mechanisms of dyspnoea and exercise intolerance in individuals with COPD. Abstract figure legend As chronic obstructive pulmonary disease severity increases, worsening gas exchange and respiratory mechanical impairment causes increased afferent receptor stimulation, increasing inspiratory neural drive at a given ventilation. The widening disparity between progressively greater inspiratory neural drive and reduced ventilatory output causes, 'neuromechanical dissociation'. This is strongly associated with a rapid increase in the intensity of dyspnea during exercise, and the onset of the sensation of 'unsatisfied inspiration'. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Matthew D James
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, ON, Canada
| | - Devin B Phillips
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, ON, Canada
| | - Sandra G Vincent
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, ON, Canada
| | - Sara J Abdallah
- Clinical Exercise and Respiratory Physiology Laboratory, Department of Kinesiology and Physical Education, Faculty of Education, McGill University, Montréal, Quebec, Canada.,Translational Research in Respiratory Diseases Program and Respiratory Epidemiology and Clinical Research Unit, Research Institute of the McGill University Health Centre, Montréal, Quebec, Canada
| | - Adamo A Donovan
- Division of Respiratory Medicine, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada
| | - Juan P de-Torres
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, ON, Canada
| | - J Alberto Neder
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, ON, Canada
| | - Benjamin M Smith
- Translational Research in Respiratory Diseases Program and Respiratory Epidemiology and Clinical Research Unit, Research Institute of the McGill University Health Centre, Montréal, Quebec, Canada.,Division of Respiratory Medicine, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada
| | - Dennis Jensen
- Clinical Exercise and Respiratory Physiology Laboratory, Department of Kinesiology and Physical Education, Faculty of Education, McGill University, Montréal, Quebec, Canada.,Translational Research in Respiratory Diseases Program and Respiratory Epidemiology and Clinical Research Unit, Research Institute of the McGill University Health Centre, Montréal, Quebec, Canada
| | - Denis E O'Donnell
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, ON, Canada
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- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, ON, Canada
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18
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Beaudry RI, Brotto AR, Varughese RA, de Waal S, Fuhr DP, Damant RW, Ferrara G, Lam GY, Smith MP, Stickland MK. Persistent dyspnea after COVID-19 is not related to cardiopulmonary impairment; a cross-sectional study of persistently dyspneic COVID-19, non-dyspneic COVID-19 and controls. Front Physiol 2022; 13:917886. [PMID: 35874528 PMCID: PMC9297912 DOI: 10.3389/fphys.2022.917886] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 06/16/2022] [Indexed: 11/21/2022] Open
Abstract
Background: Up to 53% of individuals who had mild COVID-19 experience symptoms for >3-month following infection (Long-CoV). Dyspnea is reported in 60% of Long-CoV cases and may be secondary to impaired exercise capacity (VO2peak) as a result of pulmonary, pulmonary vascular, or cardiac insult. This study examined whether cardiopulmonary mechanisms could explain exertional dyspnea in Long-CoV. Methods: A cross-sectional study of participants with Long-CoV (n = 28, age 40 ± 11 years, 214 ± 85 days post-infection) and age- sex- and body mass index-matched COVID-19 naïve controls (Con, n = 24, age 41 ± 12 years) and participants fully recovered from COVID-19 (ns-CoV, n = 14, age 37 ± 9 years, 198 ± 89 days post-infection) was conducted. Participants self-reported symptoms and baseline dyspnea (modified Medical Research Council, mMRC, dyspnea grade), then underwent a comprehensive pulmonary function test, cardiopulmonary exercise test, exercise pulmonary diffusing capacity measurement, and rest and exercise echocardiography. Results: VO2peak, pulmonary function and cardiac/pulmonary vascular parameters were not impaired in Long- or ns-CoV compared to normative values (VO2peak: 106 ± 25 and 107 ± 25%predicted, respectively) and cardiopulmonary responses to exercise were otherwise normal. When Long-CoV were stratified by clinical dyspnea severity (mMRC = 0 vs mMRC≥1), there were no between-group differences in VO2peak. During submaximal exercise, dyspnea and ventilation were increased in the mMRC≥1 group, despite normal operating lung volumes, arterial saturation, diffusing capacity and indicators of pulmonary vascular pressures. Interpretation: Persistent dyspnea after COVID-19 was not associated with overt cardiopulmonary impairment or exercise intolerance. Interventions focusing on dyspnea management may be appropriate for Long-CoV patients who report dyspnea without cardiopulmonary impairment.
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Affiliation(s)
- Rhys I. Beaudry
- Division of Pulmonary Medicine, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Andrew R. Brotto
- Division of Pulmonary Medicine, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Rhea A. Varughese
- Division of Pulmonary Medicine, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Stephanie de Waal
- Division of Pulmonary Medicine, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Desi P. Fuhr
- Division of Pulmonary Medicine, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Ronald W. Damant
- Division of Pulmonary Medicine, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Giovanni Ferrara
- Division of Pulmonary Medicine, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Grace Y. Lam
- Division of Pulmonary Medicine, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Maeve P. Smith
- Division of Pulmonary Medicine, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Michael K. Stickland
- Division of Pulmonary Medicine, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
- G.F. MacDonald Centre for Lung Health, Covenant Health, Edmonton, AB, Canada
- *Correspondence: Michael K. Stickland,
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19
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Phillips DB, Elbehairy AF, James MD, Vincent SG, Milne KM, de-Torres JP, Neder JA, Kirby M, Jensen D, Stickland MK, Guenette JA, Smith BM, Aaron SD, Tan WC, Bourbeau J, O'Donnell DE. Impaired Ventilatory Efficiency, Dyspnea and Exercise Intolerance in Chronic Obstructive Pulmonary Disease: Results from the CanCOLD Study. Am J Respir Crit Care Med 2022; 205:1391-1402. [PMID: 35333135 DOI: 10.1164/rccm.202109-2171oc] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Impaired exercise ventilatory efficiency (high ventilatory requirements for CO2 [V̇E/V̇CO2]) provides an indication of pulmonary gas exchange abnormalities in chronic obstructive pulmonary disease (COPD). OBJECTIVES To determine: 1) the association between high V̇E/V̇CO2 and clinical outcomes (dyspnea and exercise capacity) and its relationship to lung function and structural radiographic abnormalities; and 2) its prevalence in a large population-based cohort. METHODS Participants were recruited randomly from the population and underwent clinical evaluation, pulmonary function, cardiopulmonary exercise testing and chest computed tomography (CT). Impaired exercise ventilatory efficiency was defined by a nadir V̇E/V̇CO2 above the upper limit of normal (V̇E/V̇CO2>ULN), using population-based normative values. MEASUREMENTS AND MAIN RESULTS Participants included 445 never-smokers, 381 ever-smokers without airflow obstruction, 224 with GOLD 1 COPD, and 200 with GOLD 2-4 COPD. Participants with V̇E/V̇CO2>ULN were more likely to have activity-related dyspnea (Medical Research Council dyspnea scale≥2, odds ratio=1.77[1.31-2.39]) and abnormally low peak oxygen uptake (V̇O2peak<LLN, odds ratio=4.58[3.06-6.86]). The carbon monoxide transfer coefficient (KCO) had a stronger correlation with nadir V̇E/V̇CO2 (r=-0.38, p<0.001) than other relevant lung function and CT metrics. The prevalence of V̇E/V̇CO2>ULN was 24% in COPD (similar in GOLD 1 and 2-4), which was greater than in never-smokers (13%) and ever-smokers (12%). CONCLUSIONS V̇E/V̇CO2>ULN was associated with greater dyspnea and low VO2peak and was present in 24% of all participants with COPD, regardless of GOLD stage. The results show the importance of recognizing impaired exercise ventilatory efficiency as a potential contributor to dyspnea and exercise limitation, even in mild COPD.
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Affiliation(s)
| | - Amany F Elbehairy
- Queen's University and Kingston General Hospital, Medicine, Kingston, Ontario, Canada.,Alexandria University, Department of Chest Diseases, Faculty of Medicine, Alexandria, Egypt
| | - Matthew D James
- Queen's University, 4257, Medicine, Kingston, Ontario, Canada
| | | | - Kathryn M Milne
- The University of British Columbia, 8166, Medicine, Vancouver, British Columbia, Canada
| | | | - J Alberto Neder
- Queen's University, 4257, Medicine, Kingston, Ontario, Canada
| | - Miranda Kirby
- Ryerson University, Physics, Toronto, Ontario, Canada
| | - Dennis Jensen
- McGill University, Kinesiology & Physical Education, Montreal, Quebec, Canada
| | | | | | - Benjamin M Smith
- McGill University, Respiratory Medicine, Montreal, Quebec, Canada
| | - Shawn D Aaron
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Wan C Tan
- Providence Heart & Lung Institute, University of British Columbia, St Paul's Hospital, UBC James Hogg Research Centre, Vancouver, British Columbia, Canada
| | - Jean Bourbeau
- Montreal Chest Institute, CORE, Montreal, Quebec, Canada.,McGill University Health Centre, 54473, Montreal, Quebec, Canada
| | - Denis E O'Donnell
- Queen's University, Division of Respiratory and Critical Care Medicine, Department of Medicine, Kingston, Ontario, Canada;
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20
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Gelinas J, Harper M, Sasso J, Wright S, Melzer B, Agar G, Guenette J, duManoir G, Roman M, Rolf JD, Eves N. Phenotyping Cardiopulmonary Exercise Limitations in Chronic Obstructive Pulmonary Disease. Front Physiol 2022; 13:816586. [PMID: 35242051 PMCID: PMC8886157 DOI: 10.3389/fphys.2022.816586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/26/2022] [Indexed: 11/24/2022] Open
Abstract
Background Exercise limitation in chronic obstructive pulmonary disease (COPD) is commonly attributed to abnormal ventilatory mechanics and/or skeletal muscle function, while cardiovascular contributions remain relatively understudied. To date, the integrative exercise responses associated with different cardiopulmonary exercise limitation phenotypes in COPD have not been explored but may provide novel therapeutic utility. This study determined the ventilatory, cardiovascular, and metabolic responses to incremental exercise in patients with COPD with different exercise limitation phenotypes. Methods Patients with COPD (n = 95, FEV1:23–113%pred) performed a pulmonary function test and incremental cardiopulmonary exercise test. Exercise limitation phenotypes were classified as: ventilatory [peak ventilation (VEpeak)/maximal ventilatory capacity (MVC) ≥ 85% or MVC-VEpeak ≤ 11 L/min, and peak heart rate (HRpeak) < 90%pred], cardiovascular (VEpeak/MVC < 85% or MVC-VEpeak > 11 L/min, and HRpeak ≥ 90%pred), or combined (VEpeak/MVC ≥ 85% or MVC-VEpeak ≤ 11 L/min, and HRpeak ≥ 90%pred). Results FEV1 varied within phenotype: ventilatory (23–75%pred), combined (28–90%pred), and cardiovascular (68–113%pred). The cardiovascular phenotype had less static hyperinflation, a lower end-expiratory lung volume and larger tidal volume at peak exercise compared to both other phenotypes (p < 0.01 for all). The cardiovascular phenotype reached a higher VEpeak (60.8 ± 11.5 L/min vs. 45.3 ± 15.5 L/min, p = 0.002), cardiopulmonary fitness (VO2peak: 20.6 ± 4.0 ml/kg/min vs. 15.2 ± 3.3 ml/kg/min, p < 0.001), and maximum workload (103 ± 34 W vs. 72 ± 27 W, p < 0.01) vs. the ventilatory phenotype, but was similar to the combined phenotype. Conclusion Distinct exercise limitation phenotypes were identified in COPD that were not solely dependent upon airflow limitation severity. Approximately 50% of patients reached maximal heart rate, indicating that peak cardiac output and convective O2 delivery contributed to exercise limitation. Categorizing patients with COPD phenotypically may aid in optimizing exercise prescription for rehabilitative purposes.
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Affiliation(s)
- Jinelle Gelinas
- Centre for Heart, Lung and Vascular Health, University of British Columbia, Kelowna, BC, Canada
| | - Megan Harper
- Centre for Heart, Lung and Vascular Health, University of British Columbia, Kelowna, BC, Canada
| | - John Sasso
- Centre for Heart, Lung and Vascular Health, University of British Columbia, Kelowna, BC, Canada
| | - Stephen Wright
- Centre for Heart, Lung and Vascular Health, University of British Columbia, Kelowna, BC, Canada
| | - Bernie Melzer
- Interior Health Authority, Kelowna General Hospital, Kelowna, BC, Canada
| | - Gloria Agar
- Interior Health Authority, Kelowna General Hospital, Kelowna, BC, Canada
| | - Jordan Guenette
- Department of Physical Therapy and Centre for Heart Lung Innovation, University of British Columbia and St. Paul's Hospital, Vancouver, BC, Canada
| | - Gregory duManoir
- Centre for Heart, Lung and Vascular Health, University of British Columbia, Kelowna, BC, Canada
| | - Michael Roman
- Faculty of Medicine, University of Calgary, Calgary, AB, Canada
| | - J Douglass Rolf
- Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Neil Eves
- Centre for Heart, Lung and Vascular Health, University of British Columbia, Kelowna, BC, Canada
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21
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Dempsey JA, Neder JA, Phillips DB, O'Donnell DE. The physiology and pathophysiology of exercise hyperpnea. HANDBOOK OF CLINICAL NEUROLOGY 2022; 188:201-232. [PMID: 35965027 DOI: 10.1016/b978-0-323-91534-2.00001-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In health, the near-eucapnic, highly efficient hyperpnea during mild-to-moderate intensity exercise is driven by three obligatory contributions, namely, feedforward central command from supra-medullary locomotor centers, feedback from limb muscle afferents, and respiratory CO2 exchange (V̇CO2). Inhibiting each of these stimuli during exercise elicits a reduction in hyperpnea even in the continuing presence of the other major stimuli. However, the relative contribution of each stimulus to the hyperpnea remains unknown as does the means by which V̇CO2 is sensed. Mediation of the hyperventilatory response to exercise in health is attributed to the multiple feedback and feedforward stimuli resulting from muscle fatigue. In patients with COPD, diaphragm EMG amplitude and its relation to ventilatory output are used to decipher mechanisms underlying the patients' abnormal ventilatory responses, dynamic lung hyperinflation and dyspnea during exercise. Key contributions to these exercise-limiting responses across the spectrum of COPD severity include high dead space ventilation, an excessive neural drive to breathe and highly fatigable limb muscles, together with mechanical constraints on ventilation. Major controversies concerning control of exercise hyperpnea are discussed along with the need for innovative research to uncover the link of metabolism to breathing in health and disease.
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Affiliation(s)
- Jerome A Dempsey
- John Rankin Laboratory of Pulmonary Medicine, Department of Population Health Sciences, University of Wisconsin-Madison, Madison, WI, United States.
| | - J Alberto Neder
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre Kingston General Hospital Campus, Kingston, ON, Canada
| | - Devin B Phillips
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre Kingston General Hospital Campus, Kingston, ON, Canada
| | - Denis E O'Donnell
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre Kingston General Hospital Campus, Kingston, ON, Canada
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22
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Phillips DB, Neder JA, Elbehairy AF, Milne KM, James MD, Vincent SG, Day AG, DE-Torres JP, Webb KA, O'Donnell DE. Qualitative Components of Dyspnea during Incremental Exercise across the COPD Continuum. Med Sci Sports Exerc 2021; 53:2467-2476. [PMID: 34649264 DOI: 10.1249/mss.0000000000002741] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Evaluation of the intensity and quality of activity-related dyspnea is potentially useful in people with chronic obstructive pulmonary disease (COPD). The present study sought to examine associations between qualitative dyspnea descriptors, dyspnea intensity ratings, dynamic respiratory mechanics, and exercise capacity during cardiopulmonary exercise testing (CPET) in COPD and healthy controls. METHODS In this cross-sectional study, 261 patients with mild-to-very severe COPD (forced expiratory volume in 1 s, 62 ± 25%pred) and 94 age-matched controls (forced expiratory volume in 1 s, 114 ± 14%pred) completed an incremental cycle CPET to determine peak oxygen uptake (V˙O2peak). Throughout exercise, expired gases, operating lung volumes, and dyspnea intensity were assessed. At peak exercise, dyspnea quality was assessed using a modified 15-item questionnaire. RESULTS Logistic regression analysis revealed that among 15 dyspnea descriptors, only those alluding to the cluster "unsatisfied inspiration" were consistently associated with an increased likelihood for both critical inspiratory mechanical constraint (end-inspiratory lung volume/total lung capacity ratio ≥0.9) during exercise and reduced exercise capacity (V˙O2peak < lower limit of normal) in COPD (odds ratio (95% confidence interval), 3.26 (1.40-7.60) and 3.04 (1.24-7.45), respectively; both, P < 0.05). Thus, patients reporting "unsatisfied inspiration" (n = 177 (68%)) had an increased relative frequency of critical inspiratory mechanical constraint and low exercise capacity compared with those who did not select this descriptor, regardless of COPD severity or peak dyspnea intensity scores. CONCLUSIONS In patients with COPD, regardless of disease severity, reporting descriptors in the unsatisfied inspiration cluster complemented traditional assessments of dyspnea during CPET and helped identify patients with critical mechanical abnormalities germane to exercise intolerance.
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Affiliation(s)
- Devin B Phillips
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, CANADA
| | - J Alberto Neder
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, CANADA
| | | | | | - Matthew D James
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, CANADA
| | - Sandra G Vincent
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, CANADA
| | - Andrew G Day
- Kingston General Hospital Health Research Institute, Kingston, Ontario, CANADA
| | - Juan P DE-Torres
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, CANADA
| | - Katherine A Webb
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, CANADA
| | - Denis E O'Donnell
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, CANADA
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23
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Niro F, Dubuc B, Gaynor-Sodeifi K, Jensen D. Effect of end-inspiratory lung volume and breathing pattern on neural activation of the diaphragm and extra-diaphragmatic inspiratory muscles in healthy adults. J Appl Physiol (1985) 2021; 131:1679-1690. [PMID: 34734781 DOI: 10.1152/japplphysiol.01118.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study examined the effect of changes in end-inspiratory lung volume (EILV) and breathing pattern on neural activation of the crural diaphragm (EMGDIA) and of the sternocleidomastoid (EMGSCM), scalene (EMGSCA) and external intercostal muscles (EMGINT) at constant ventilation (V̇E). Twelve healthy adults performed a series of 30-sec breathing trials at a constant V̇E corresponding to 15% of their maximum voluntary ventilation while (i) altering EILV at a constant breathing pattern and (ii) altering breathing pattern at a constant EILV. Using a real-time visual display of each participant's spirogram, EILV was voluntarily targeted at 65% (EILV65%), 75% (EILV75%), 85% (EILV85%) and 95% (EILV95%) of each participant's inspired vital capacity, while breathing frequency (fR) was targeted at 15, 35 and 50 breaths/min using a metronome. The tidal volume needed for a participant to maintain V̇E constant across trials was achieved via changes in end-expiratory lung volume. A multipair esophageal electrode catheter was used to record EMGDIA, while surface electrodes were used to record EMGSCM, EMGSCA and EMGINT. On average, EMGDIA, EMGSCM, EMGSCA and EMGINT increased as a function of increasing EILV at constant V̇E, independent of changes in breathing pattern. The magnitudes of these increases were particularly notable in the transition from EILV85% to EILV95%, especially for EMGSCM and EMGSCA. In healthy adults, as EILV increases towards total lung capacity, progressive compensatory increases in neural activation of the diaphragm and extra-diaphragmatic inspiratory muscles are needed to support V̇E, independent of changes in breathing pattern.
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Affiliation(s)
- Frank Niro
- Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
| | - Benjamin Dubuc
- Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
| | - Kaveh Gaynor-Sodeifi
- Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
| | - Dennis Jensen
- Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada.,Research Institute of the McGill University Health Centre, Translational Research in Respiratory Diseases Program, Montreal, Quebec, Canada.,Research Centre for Physical Activity and Health, Faculty of Education, McGill University, Montréal, Quebec, Canada
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24
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Syed N, Ryu MH, Dhillon S, Schaeffer MR, Ramsook AH, Leung JM, Ryerson CJ, Carlsten C, Guenette JA. Effects of traffic-related air pollution on exercise endurance, dyspnea and cardiorespiratory physiology in health and COPD - A randomized, placebo-controlled crossover trial. Chest 2021; 161:662-675. [PMID: 34699772 DOI: 10.1016/j.chest.2021.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/22/2021] [Accepted: 10/02/2021] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Individuals with COPD have increased sensitivity to traffic-related air pollution (TRAP) such as diesel exhaust (DE), but little is known about the acute effects of TRAP on exercise responses in COPD. RESEARCH QUESTION Does pre-exercise exposure to TRAP (DE300, PM2.5=300 μg/m3) have greater adverse effects on exercise endurance, exertional dyspnea, and cardiorespiratory responses to exercise in participants with mild-to-moderate COPD compared to former smokers with normal spirometry and healthy controls? STUDY DESIGN AND METHODS In this double-blind, randomized, placebo-controlled, crossover study, 11 healthy never-smokers, 9 ex-smokers without COPD and 9 ex-smokers with COPD were separately exposed to filtered air (FA) and DE300 for 2 hours separated by a minimum of 4 weeks. Participants performed symptom limited constant load cycling tests within 2.5 hours of exposure with detailed cardiorespiratory and exertional symptom measurements. RESULTS There was a significant negative effect of TRAP on exercise endurance time in healthy controls (DE300 vs. FA: 10.2±8.2 vs. 12.9±9.5 min, respectively; p=0.03), but not in ex-smokers without COPD (10.1±6.9 vs. 12.2±8.0 min; respectively, p=0.57) or ex-smokers with COPD (9.8±6.4 vs. 8.4±6.6 min, respectively, p=0.31). Furthermore, significant increases in inspiratory duty cycle and absolute end-expiratory and end-inspiratory lung volumes were observed, and dyspnea ratings were elevated at select submaximal measurement times only in healthy controls. INTERPRETATION: Contrary to our hypothesis, it was the healthy controls rather than the ex-smokers with and without COPD that were negatively impacted by TRAP during exercise.
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Affiliation(s)
- Nafeez Syed
- Centre for Heart Lung Innovation, The University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada; Department of Physical Therapy, The University of British Columbia, Vancouver, BC, Canada
| | - Min Hyung Ryu
- Centre for Heart Lung Innovation, The University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada; Department of Medicine, The University of British Columbia, Vancouver, BC, Canada
| | - Satvir Dhillon
- Centre for Heart Lung Innovation, The University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada
| | - Michele R Schaeffer
- Centre for Heart Lung Innovation, The University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada; Department of Physical Therapy, The University of British Columbia, Vancouver, BC, Canada
| | - Andrew H Ramsook
- Centre for Heart Lung Innovation, The University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada; Department of Physical Therapy, The University of British Columbia, Vancouver, BC, Canada
| | - Janice M Leung
- Centre for Heart Lung Innovation, The University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada; Department of Medicine, The University of British Columbia, Vancouver, BC, Canada
| | - Christopher J Ryerson
- Centre for Heart Lung Innovation, The University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada; Department of Medicine, The University of British Columbia, Vancouver, BC, Canada
| | - Christopher Carlsten
- Centre for Heart Lung Innovation, The University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada; Department of Medicine, The University of British Columbia, Vancouver, BC, Canada
| | - Jordan A Guenette
- Centre for Heart Lung Innovation, The University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada; Department of Physical Therapy, The University of British Columbia, Vancouver, BC, Canada.
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25
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Neder JA, Berton DC, Phillips DB, O'Donnell DE. Exertional ventilation/carbon dioxide output relationship in COPD: from physiological mechanisms to clinical applications. Eur Respir Rev 2021; 30:30/161/200190. [PMID: 34526312 PMCID: PMC9489189 DOI: 10.1183/16000617.0190-2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 09/30/2020] [Indexed: 01/09/2023] Open
Abstract
There is well established evidence that the minute ventilation (V′E)/carbon dioxide output (V′CO2) relationship is relevant to a number of patient-related outcomes in COPD. In most circumstances, an increased V′E/V′CO2 reflects an enlarged physiological dead space (“wasted” ventilation), although alveolar hyperventilation (largely due to increased chemosensitivity) may play an adjunct role, particularly in patients with coexistent cardiovascular disease. The V′E/V′CO2 nadir, in particular, has been found to be an important predictor of dyspnoea and poor exercise tolerance, even in patients with largely preserved forced expiratory volume in 1 s. As the disease progresses, a high nadir might help to unravel the cause of disproportionate breathlessness. When analysed in association with measurements of dynamic inspiratory constraints, a high V′E/V′CO2 is valuable to ascertain a role for the “lungs” in limiting dyspnoeic patients. Regardless of disease severity, cardiocirculatory (heart failure and pulmonary hypertension) and respiratory (lung fibrosis) comorbidities can further increase V′E/V′CO2. A high V′E/V′CO2 is a predictor of poor outcome in lung resection surgery, adding value to resting lung hyperinflation in predicting all-cause and respiratory mortality across the spectrum of disease severity. Considering its potential usefulness, the V′E/V′CO2 should be valued in the clinical management of patients with COPD. The minute ventilation/carbon dioxide production relationship is relevant to a number of patient-related outcomes in COPD. Minute ventilation/carbon dioxide production, therefore, should be valued in the clinical management of these patients.https://bit.ly/3df2upH
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Affiliation(s)
- J Alberto Neder
- Respiratory Investigation Unit and Laboratory of Clinical Exercise Physiology, Queen's University and Kingston General Hospital, Kingston, ON, Canada
| | - Danilo C Berton
- Respiratory Investigation Unit and Laboratory of Clinical Exercise Physiology, Queen's University and Kingston General Hospital, Kingston, ON, Canada.,Division of Respiratory Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Devin B Phillips
- Respiratory Investigation Unit and Laboratory of Clinical Exercise Physiology, Queen's University and Kingston General Hospital, Kingston, ON, Canada
| | - Denis E O'Donnell
- Respiratory Investigation Unit and Laboratory of Clinical Exercise Physiology, Queen's University and Kingston General Hospital, Kingston, ON, Canada
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26
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James MD, Phillips DB, Elbehairy AF, Milne KM, Vincent SG, Domnik NJ, de Torres JP, Neder JA, O'Donnell DE. Mechanisms of Exertional Dyspnea in Patients with Mild COPD and a Low Resting DL CO. COPD 2021; 18:501-510. [PMID: 34496691 DOI: 10.1080/15412555.2021.1932782] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Patients with mild chronic obstructive pulmonary disease (COPD) and lower resting diffusing capacity for carbon monoxide (DLCO) often report troublesome dyspnea during exercise although the mechanisms are not clear. We postulated that in such individuals, exertional dyspnea is linked to relatively high inspiratory neural drive (IND) due, in part, to the effects of reduced ventilatory efficiency. This cross-sectional study included 28 patients with GOLD I COPD stratified into two groups with (n = 15) and without (n = 13) DLCO less than the lower limit of normal (<LLN; Global Lung Function Initiative criteria) and 16 healthy controls. We compared dyspnea (Borg scale), IND (by diaphragm electromyography), ventilatory equivalent for CO2 (V̇E/V̇CO2), and respiratory mechanics during incremental cycle exercise in the three groups. Spirometry and resting lung volumes were similar between COPD groups. During exercise, dyspnea, IND and V̇E/V̇CO2 were higher at equivalent work rates (WR) in the DLCO<LLN group compared with the other two groups (all p < 0.05). In patients with DLCO<LLN, severe respiratory mechanical constraints, indicated by end-inspiratory lung volume of approximately 90% of total lung capacity, occurred at a lower WR than the other two groups (p < 0.05). The dyspnea/IND relationship was similar across groups; therefore, the increased dyspnea at a standardized WR in the low DLCO<LLN group reflected the higher corresponding IND. Higher dyspnea ratings in patients with mild COPD and DLCO<LLN were associated with higher IND and V̇E/V̇CO2 at a given work rate. Higher ventilatory requirements in the DLCO<LLN group accelerated dynamic mechanical abnormalities earlier in exercise, further increasing IND and dyspnea.
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Affiliation(s)
- Matthew D James
- Respiratory Investigation Unit, Department of Medicine, Queen's University, and Kingston Health Sciences Centre, Kingston, Ontario, Canada
| | - Devin B Phillips
- Respiratory Investigation Unit, Department of Medicine, Queen's University, and Kingston Health Sciences Centre, Kingston, Ontario, Canada
| | - Amany F Elbehairy
- Respiratory Investigation Unit, Department of Medicine, Queen's University, and Kingston Health Sciences Centre, Kingston, Ontario, Canada.,Department of Chest Diseases, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Kathryn M Milne
- Respiratory Investigation Unit, Department of Medicine, Queen's University, and Kingston Health Sciences Centre, Kingston, Ontario, Canada.,Centre for Heart Lung Innovation, Providence Health Care Research Institute, University of British Colombia, St. Paul's Hospital, Vancouver, British Columbia, Canada.,Division of Respiratory Medicine, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sandra G Vincent
- Respiratory Investigation Unit, Department of Medicine, Queen's University, and Kingston Health Sciences Centre, Kingston, Ontario, Canada
| | - Nicolle J Domnik
- Respiratory Investigation Unit, Department of Medicine, Queen's University, and Kingston Health Sciences Centre, Kingston, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Juan P de Torres
- Respiratory Investigation Unit, Department of Medicine, Queen's University, and Kingston Health Sciences Centre, Kingston, Ontario, Canada
| | - J Alberto Neder
- Respiratory Investigation Unit, Department of Medicine, Queen's University, and Kingston Health Sciences Centre, Kingston, Ontario, Canada
| | - Denis E O'Donnell
- Respiratory Investigation Unit, Department of Medicine, Queen's University, and Kingston Health Sciences Centre, Kingston, Ontario, Canada
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Cross TJ, Gideon EA, Morris SJ, Coriell CL, Hubbard CD, Duke JW. A comparison of methods used to quantify the work of breathing during exercise. J Appl Physiol (1985) 2021; 131:1123-1133. [PMID: 34410846 DOI: 10.1152/japplphysiol.00411.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mechanical work of breathing (Wb) is an insightful tool used to assess respiratory mechanics during exercise. There are several different methods used to calculate the Wb, however, each approach having its own distinct advantages/disadvantages. To date, a comprehensive assessment of the differences in the components of Wb between these methods is lacking. We therefore sought to compare the values of Wb during graded exercise as determined via the four most popular methods: 1) pressure-volume integration; 2) the Hedstrand diagram; 3) the Otis diagram; and the 4) modified Campbell diagram. Forty-two participants (30 ± 15 yr; 16 women) performed graded cycling to volitional exhaustion. Esophageal pressure-volume loops were obtained throughout exercise. These data were used to calculate the total Wb and, where possible, its subcomponents of inspiratory and expiratory, resistive and elastic Wb, using each of the four methods. Our results demonstrate that the components of Wb were indeed different between methods across the minute ventilations engendered by graded exercise. Importantly, however, no systematic pattern in these differences could be observed. Our findings indicate that the values of Wb obtained during exercise are uniquely determined by the specific method chosen to compute its value-no two methods yield identical results. Because there is currently no "gold-standard" for measuring the Wb, it is emphasized that future investigators be cognizant of the limitations incurred by their chosen method, such that observations made by others may be interpreted with greater context, and transparency.NEW & NOTEWORTHY The measurement of the work of breathing (Wb) during exercise provides us with deep insights into respiratory (patho)physiology, and sheds light on the putative factors which lead to respiratory muscle fatigue. There are 4 popular methods available to determine the Wb. Our study demonstrates that no two of these methods produce identical values of Wb during exercise. This paper also discusses the practical and theoretical limitations of each method.
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Affiliation(s)
- Troy J Cross
- Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia.,Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | - Elizabeth A Gideon
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
| | - Sarah J Morris
- Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Catherine L Coriell
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
| | - Colin D Hubbard
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
| | - Joseph W Duke
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
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Neder JA, de Torres JP, O'Donnell DE. Recent Advances in the Physiological Assessment of Dyspneic Patients with Mild COPD. COPD 2021; 18:374-384. [PMID: 33902376 DOI: 10.1080/15412555.2021.1913110] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
There is growing recognition that a sizable fraction of COPD patients with forced expiratory volume in one second (FEV1)/forced vital capacity ratio below the lower limit of normal but preserved FEV1 reports out-of-proportion dyspnea relative to the severity of airflow limitation. Most physicians, however, assume that patients' breathlessness is unlikely to reflect the negative physiological consequences of COPD vis-à-vis FEV1 normalcy. This concise review integrates the findings of recent studies which uncovered the key pathophysiological features shared by these patients: poor pulmonary gas exchange efficiency (increased "wasted" ventilation) and gas trapping. These abnormalities are associated with two well-known causes of exertional dyspnea: heightened ventilation relative to metabolic demand and critically low inspiratory reserves, respectively. From a clinical standpoint, a low diffusion capacity associated with increased residual volume (RV) and/or RV/total lung capacity ratio might uncover these disturbances, identifying the subset of patients in whom exertional dyspnea is causally related to "mild" COPD.
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Affiliation(s)
- J Alberto Neder
- Laboratory of Clinical Exercise Physiology and Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University & Kingston General Hospital, Kingston, ON, Canada
| | - Juan P de Torres
- Laboratory of Clinical Exercise Physiology and Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University & Kingston General Hospital, Kingston, ON, Canada
| | - Denis E O'Donnell
- Laboratory of Clinical Exercise Physiology and Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Queen's University & Kingston General Hospital, Kingston, ON, Canada
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Phillips DB, James MD, Elbehairy AF, Milne KM, Vincent SG, Domnik NJ, de-Torres JP, Neder JA, O'Donnell DE. Reduced exercise tolerance in mild chronic obstructive pulmonary disease: The contribution of combined abnormalities of diffusing capacity for carbon monoxide and ventilatory efficiency. Respirology 2021; 26:786-795. [PMID: 33829588 DOI: 10.1111/resp.14045] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 02/26/2021] [Accepted: 03/08/2021] [Indexed: 01/15/2023]
Abstract
BACKGROUND AND OBJECTIVE The combination of both reduced resting diffusing capacity of the lung for carbon monoxide (DLCO ) and ventilatory efficiency (increased ventilatory requirement for CO2 clearance [V˙E /V˙CO2 ]) has been linked to exertional dyspnoea and exercise intolerance in chronic obstructive pulmonary disease (COPD) but the underlying mechanisms are poorly understood. The current study examined if low resting DLCO and higher exercise ventilatory requirements were associated with earlier critical dynamic mechanical constraints, dyspnoea and exercise limitation in patients with mild COPD. METHODS In this retrospective analysis, we compared V˙E /V˙CO2 , dynamic inspiratory reserve volume (IRV), dyspnoea and exercise capacity in groups of patients with Global Initiative for Chronic Obstructive Lung Disease stage 1 COPD with (1) a resting DLCO at or greater than the lower limit of normal (≥LLN; Global Lung Function Initiative reference equations [n = 44]) or (2) below the <LLN (n = 33), and age- and sex-matched healthy controls (n = 81). RESULTS Spirometry and resting lung volumes were similar in the two COPD groups. During exercise, V˙E /V˙CO2 (nadir and slope) was consistently higher in the DLCO < LLN compared with the other groups (all p < 0.05). The DLCO < LLN group had lower IRV and greater dyspnoea intensity at standardized submaximal work rates and lower peak work rate and oxygen uptake than the other two groups (all p < 0.05). CONCLUSION Reduced exercise capacity in patients with DLCO < LLN was related to higher ventilatory requirements, a faster rate of decline in dynamic IRV and greater dyspnoea during exercise. These simple measurements should be considered for the clinical evaluation of unexplained exercise intolerance in individuals with ostensibly mild COPD.
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Affiliation(s)
- Devin B Phillips
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, Canada
| | - Matthew D James
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, Canada
| | - Amany F Elbehairy
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, Canada.,Department of Chest Diseases, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Kathryn M Milne
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, Canada.,Department of Medicine Clinician Investigator Program, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sandra G Vincent
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, Canada
| | - Nicolle J Domnik
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, Canada
| | - Juan P de-Torres
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, Canada
| | - J Alberto Neder
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, Canada
| | - Denis E O'Donnell
- Respiratory Investigation Unit, Department of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston General Hospital Campus, Kingston, Ontario, Canada
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30
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Cherian M, Jensen D, Tan WC, Mursleen S, Goodall EC, Nadeau GA, Awan AM, Marciniuk DD, Walker BL, Aaron SD, O'Donnell DE, Chapman KR, Maltais F, Hernandez P, Sin DD, Benedetti A, Bourbeau J. Dyspnoea and symptom burden in mild-moderate COPD: the Canadian Cohort Obstructive Lung Disease Study. ERJ Open Res 2021; 7:00960-2020. [PMID: 33898621 PMCID: PMC8053913 DOI: 10.1183/23120541.00960-2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 12/21/2020] [Indexed: 12/31/2022] Open
Abstract
Studies assessing dyspnoea and health-related quality of life (HRQoL) in chronic obstructive pulmonary disease (COPD) have focussed on patients in clinical settings, not the general population. The aim of this analysis was to compare the prevalence and severity of dyspnoea and impaired HRQoL in individuals with and without COPD from the general population, focussing on mild-moderate COPD. Analysis of the 3-year Canadian Cohort Obstructive Lung Disease (CanCOLD) study included four subgroups: mild COPD (Global Initiative for Chronic Obstructive Lung Disease (GOLD) 1); moderate COPD (GOLD 2); non-COPD smokers; and non-COPD never-smokers. The primary outcome was dyspnoea (Medical Research Council (MRC) scale), and the secondary outcome was HRQoL (COPD Assessment Test (CAT) score; Saint George's Respiratory Questionnaire (SGRQ) score). Subgroups were analysed by sex, physician-diagnosed COPD status and exacerbations. 1443 participants (mild COPD (n=397); moderate COPD (n=262(; smokers (n=449) and never-smokers (n=335)) were studied. People with mild COPD were more likely to report more severe dyspnoea (MRC 2 versus 1) than those without COPD (OR (95% CI) 1.42 (1.05-1.91)), and non-COPD never-smokers (OR (95%CI) 1.64 (1.07-2.52)). Among people with mild COPD, more severe dyspnoea was reported in women versus men (MRC2 versus 1; OR (95% CI) 3.70 (2.23-6.14)); people with, versus without, physician-diagnosed COPD (MRC2 versus 1; OR (95% CI) 3.27 (1.71-6.23)), and people with versus without recent exacerbations (MRC2 versus 1; ≥2 versus 0 exacerbations: OR (95% CI) 3.62 (1.02-12.86); MRC ≥3 versus 1; 1 versus 0 exacerbation: OR (95% CI): 9.24 (2.01-42.42)). Similar between-group differences were obtained for CAT and SGRQ scores. Careful assessment of dyspnoea and HRQoL could help identify individuals for earlier diagnosis and treatment.
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Affiliation(s)
- Mathew Cherian
- Division of Respiratory Medicine, Dept of Medicine, McGill University Health Centre, Montreal, QC, Canada
| | - Dennis Jensen
- Clinical Exercise and Respiratory Physiology Laboratory, Dept of Kinesiology and Physical Education, Faculty of Education, McGill University, Montréal, QC, Canada
- Research Institute of the McGill University Health Centre, Translational Research in Respiratory Diseases Program and Respiratory Epidemiology and Clinical Research Unit, Montréal, QC, Canada
- Research Centre for Physical Activity and Health, Faculty of Education, McGill University, Montréal, QC, Canada
| | - Wan C. Tan
- Centre for Heart Lung Innovation, Dept of Medicine, University of British Columbia, Vancouver, BC, Canada
| | | | | | | | | | - Darcy D. Marciniuk
- Respiratory Research Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Brandie L. Walker
- Division of Respirology, Dept of Medicine, University of Calgary, Calgary, AB, Canada
| | - Shawn D. Aaron
- The Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | | | - Kenneth R. Chapman
- Asthma and Airway Centre, University Health Network and University of Toronto, Toronto, ON, Canada
| | - François Maltais
- Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC, Canada
| | - Paul Hernandez
- Faculty of Medicine, Division of Respirology, Dalhousie University, Halifax, NS, Canada
| | - Don D. Sin
- Centre for Heart Lung Innovation, Dept of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Andrea Benedetti
- Depts of Medicine and of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, QC, Canada
- Respiratory Epidemiology and Clinical Research Unit, McGill University, Montreal, QC, Canada
| | - Jean Bourbeau
- Division of Respiratory Medicine, Dept of Medicine, McGill University Health Centre, Montreal, QC, Canada
- Research Institute of the McGill University Health Centre, Translational Research in Respiratory Diseases Program and Respiratory Epidemiology and Clinical Research Unit, Montréal, QC, Canada
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31
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Sieck DC, Sieck GC. Improving gas exchange and exercise tolerance in mild COPD patients. J Physiol 2021; 599:1943-1944. [PMID: 33576012 DOI: 10.1113/jp281323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 02/08/2021] [Indexed: 11/08/2022] Open
Affiliation(s)
| | - Gary C Sieck
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
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32
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Phillips DB, Domnik NJ, Elbehairy AF, Preston ME, Milne KM, James MD, Vincent SG, Ibrahim-Masthan M, Neder JA, O’Donnell DE. Elevated exercise ventilation in mild COPD is not linked to enhanced central chemosensitivity. Respir Physiol Neurobiol 2021; 284:103571. [DOI: 10.1016/j.resp.2020.103571] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 10/27/2020] [Accepted: 11/01/2020] [Indexed: 11/25/2022]
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Phillips DB, Brotto AR, Ross BA, Bryan TL, Wong EYL, Meah VL, Fuhr DP, van Diepen S, Stickland MK. Inhaled nitric oxide improves ventilatory efficiency and exercise capacity in patients with mild COPD: A randomized-control cross-over trial. J Physiol 2021; 599:1665-1683. [PMID: 33428233 DOI: 10.1113/jp280913] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 12/22/2020] [Indexed: 01/01/2023] Open
Abstract
KEY POINTS Patients with mild chronic obstructive pulmonary disease (COPD) have an elevated ventilatory equivalent to CO2 production ( V ̇ E / V ̇ C O 2 ) during exercise, secondary to increased dead space ventilation. The reason for the increased dead space is unclear, although pulmonary microvascular dysfunction and the corresponding capillary hypoperfusion is a potential mechanism. Despite emerging evidence that mild COPD is associated with pulmonary microvascular dysfunction, limited research has focused on experimentally modulating the pulmonary microvasculature during exercise in mild COPD. The present study sought to examine the effect of inhaled nitric oxide (iNO), a selective pulmonary vasodilator, on V ̇ E / V ̇ C O 2 , dyspnoea and exercise capacity in patients with mild COPD. Experimental iNO increased peak oxygen uptake in mild COPD, secondary to reduced V ̇ E / V ̇ C O 2 and dyspnoea. This is the first study to demonstrate that experimental manipulation of the pulmonary circulation alone, can positively impact dyspnoea and exercise capacity in mild COPD. ABSTRACT Patients with mild chronic obstructive pulmonary disease (COPD) have an exaggerated ventilatory response to exercise, contributing to dyspnoea and exercise intolerance. Previous research in mild COPD has demonstrated an elevated ventilatory equivalent to CO2 production ( V ̇ E / V ̇ C O 2 ) during exercise, secondary to increased dead space ventilation. The reason for the increased dead space is unclear, although pulmonary microvascular dysfunction and the corresponding capillary hypoperfusion is a potential mechanism. The present study tested the hypothesis that inhaled nitric oxide (iNO), a selective pulmonary vasodilator, would lower V ̇ E / V ̇ C O 2 and dyspnoea, and improve exercise capacity in patients with mild COPD. In this multigroup randomized-control cross-over study, 15 patients with mild COPD (FEV1 = 89 ± 11% predicted) and 15 healthy controls completed symptom-limited cardiopulmonary exercise tests while breathing normoxic gas or 40 ppm iNO. Compared with placebo, iNO significantly increased peak oxygen uptake (1.80 ± 0.14 vs. 1.53 ± 0.10 L·min-1 , P < 0.001) in COPD, whereas no effect was observed in controls. At an equivalent work rate of 60 W, iNO reduced V ̇ E / V ̇ C O 2 by 3.8 ± 4.2 units (P = 0.002) and dyspnoea by 1.1 ± 1.2 Borg units (P < 0.001) in COPD, whereas no effect was observed in controls. Operating lung volumes and oxygen saturation were unaffected by iNO in both groups. iNO increased peak oxygen uptake in COPD, secondary to reduced V ̇ E / V ̇ C O 2 and dyspnoea. These data suggest that mild COPD patients demonstrate pulmonary microvascular dysfunction that contributes to increased V ̇ E / V ̇ C O 2 , dyspnoea and exercise intolerance. This is the first study to demonstrate that experimental manipulation of the pulmonary circulation alone, can positively impact dyspnoea and exercise capacity in mild COPD.
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Affiliation(s)
- Devin B Phillips
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Andrew R Brotto
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Bryan A Ross
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Tracey L Bryan
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Eric Y L Wong
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Victoria L Meah
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Desi P Fuhr
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Sean van Diepen
- Department of Critical Care and Division of Cardiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Michael K Stickland
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,G.F. MacDonald Centre for Lung Health, Covenant Health, Edmonton, Alberta, Canada
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Rodrigues A, Louvaris Z, Dacha S, Janssens W, Pitta F, Vogiatzis I, Gosselink R, Langer D. Differences in Respiratory Muscle Responses to Hyperpnea or Loaded Breathing in COPD. Med Sci Sports Exerc 2020; 52:1126-1134. [PMID: 31876666 DOI: 10.1249/mss.0000000000002222] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION We aimed to compare acute mechanical and metabolic responses of the diaphragm and rib cage inspiratory muscles during two different types of respiratory loading in patients with chronic obstructive pulmonary disease. METHODS In 16 patients (age, 65 ± 13 yr; 56% male; forced expiratory volume in the first second, 60 ± 6%pred; maximum inspiratory pressure, 82 ± 5%pred), assessments of respiratory muscle EMG, esophageal pressure (Pes) and gastric pressures, breathing pattern, and noninvasive assessments of systemic (V˙O2, cardiac output, oxygen delivery and extraction) and respiratory muscle hemodynamic and oxygenation responses (blood flow index, oxygen delivery index, deoxyhemoglobin concentration, and tissues oxygen saturation [StiO2]), were performed during hyperpnea and loaded breathing. RESULTS During hyperpnea, breathing frequency, minute ventilation, esophageal and diaphragm pressure-time product per minute, cardiac output, and V˙O2 were higher than during loaded breathing (P < 0.05). Average inspiratory Pes and transdiaphragmatic pressure per breath, scalene (SCA), sternocleidomastoid, and intercostal muscle activation were higher during loading breathing compared with hyperpnea (P < 0.05). Higher transdiaphragmatic pressure during loaded breathing compared with hyperpnea was mostly due to higher inspiratory Pes (P < 0.05). Diaphragm activation, inspiratory and expiratory gastric pressures, and rectus abdominis muscle activation did not differ between the two conditions (P > 0.05). SCA-blood flow index and oxygen delivery index were lower, and SCA-deoxyhemoglobin concentration was higher during loaded breathing compared with hyperpnea. Furthermore, SCA and intercostal muscle StiO2 were lower during loaded breathing compared with hyperpnea (P < 0.05). CONCLUSION Greater inspiratory muscle effort during loaded breathing evoked larger rib cage and neck muscle activation compared with hyperpnea. In addition, lower SCA and intercostal muscle StiO2 during loaded breathing compared with hyperpnea indicates a mismatch between inspiratory muscle oxygen delivery and utilization induced by the former condition.
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Affiliation(s)
| | | | | | | | - Fabio Pitta
- Laboratory of Research in Respiratory Physiotherapy (LFIP), Department of Physiotherapy, Universidade Estadual de Londrina (UEL), Londrina, BRAZIL
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Elbehairy AF, Faisal A, McIsaac H, Domnik NJ, Milne KM, James MD, Neder JA, O'Donnell DE. Mechanisms of orthopnoea in patients with advanced COPD. Eur Respir J 2020; 57:13993003.00754-2020. [PMID: 32972985 DOI: 10.1183/13993003.00754-2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 09/15/2020] [Indexed: 01/18/2023]
Abstract
Many patients with severe chronic obstructive pulmonary disease (COPD) report an unpleasant respiratory sensation at rest, which is further amplified by adoption of a supine position (orthopnoea). The mechanisms of this acute symptomatic deterioration are poorly understood.Sixteen patients with advanced COPD and a history of orthopnoea and 16 age- and sex-matched healthy controls underwent pulmonary function tests (PFTs) and detailed sensory-mechanical measurements including inspiratory neural drive (IND) assessed by diaphragm electromyography (EMGdi), oesophageal pressure (P es) and gastric pressure (P ga), in both sitting and supine positions.Patients had severe airflow obstruction (forced expiratory volume in 1 s (FEV1): 40±18% pred) and lung hyperinflation. Regardless of the position, patients had lower inspiratory capacity (IC) and higher IND for a given tidal volume (V T) (i.e. greater neuromechanical dissociation (NMD)), higher intensity of breathing discomfort, higher minute ventilation (V'E) and higher breathing frequency (f B) compared with controls (all p<0.05). For controls in a supine position, IC increased by 0.48 L versus sitting erect, with a small drop in V'E, mainly due to reduced f B (all p<0.05). By contrast, IC remained unaltered in patients with COPD, but dynamic lung compliance (C Ldyn) decreased (p<0.05) in the supine position. Breathing discomfort, inspiratory work of breathing (WOB), inspiratory effort, IND, NMD and neuroventilatory uncoupling all increased in COPD patients in the supine position (p<0.05), but not in the healthy controls. Orthopnoea was associated with acute changes in IND (r=0.65, p=0.01), neuroventilatory uncoupling (r=0.76, p=0.001) and NMD (r=0.73, p=0.002).In COPD, onset of orthopnoea coincided with an abrupt increase in elastic loading of the inspiratory muscles in recumbency, in association with increased IND and greater NMD of the respiratory system.
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Affiliation(s)
- Amany F Elbehairy
- Division of Respiratory Medicine, Dept of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, ON, Canada.,Dept of Chest Diseases, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Azmy Faisal
- Dept of Sport and Exercise Sciences, Manchester Metropolitan University, Manchester, UK.,Faculty of Physical Education for Men, Alexandria University, Alexandria, Egypt
| | - Hannah McIsaac
- Division of Respiratory Medicine, Dept of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, ON, Canada
| | - Nicolle J Domnik
- Division of Respiratory Medicine, Dept of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, ON, Canada
| | - Kathryn M Milne
- Division of Respiratory Medicine, Dept of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, ON, Canada.,Clinician Investigator Program, Dept of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Matthew D James
- Division of Respiratory Medicine, Dept of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, ON, Canada
| | - J Alberto Neder
- Division of Respiratory Medicine, Dept of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, ON, Canada
| | - Denis E O'Donnell
- Division of Respiratory Medicine, Dept of Medicine, Queen's University and Kingston Health Sciences Centre, Kingston, ON, Canada
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36
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Milne KM, Domnik NJ, Phillips DB, James MD, Vincent SG, Neder JA, O'Donnell DE. Evaluation of Dynamic Respiratory Mechanical Abnormalities During Conventional CPET. Front Med (Lausanne) 2020; 7:548. [PMID: 33072774 PMCID: PMC7533639 DOI: 10.3389/fmed.2020.00548] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/31/2020] [Indexed: 12/21/2022] Open
Abstract
Assessment of the ventilatory response to exercise is important in evaluating mechanisms of dyspnea and exercise intolerance in chronic cardiopulmonary diseases. The characteristic mechanical derangements that occur during exercise in chronic respiratory conditions have previously been determined in seminal studies using esophageal catheter pressure-derived measurements. In this brief review, we examine the emerging role and clinical utility of conventional assessment of dynamic respiratory mechanics during exercise testing. Thus, we provide a physiologic rationale for measuring operating lung volumes, breathing pattern, and flow-volume loops during exercise. We consider standardization of inspiratory capacity-derived measurements and their practical implementation in clinical laboratories. We examine the evidence that this iterative approach allows greater refinement in evaluation of ventilatory limitation during exercise than traditional assessments of breathing reserve. We appraise the available data on the reproducibility and responsiveness of this methodology. In particular, we review inspiratory capacity measurement and derived operating lung volumes during exercise. We demonstrate, using recent published data, how systematic evaluation of dynamic mechanical constraints, together with breathing pattern analysis, can provide valuable insights into the nature and extent of physiological impairment contributing to exercise intolerance in individuals with common chronic obstructive and restrictive respiratory disorders.
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Affiliation(s)
- Kathryn M Milne
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Kingston Health Sciences Centre & Queen's University, Kingston, ON, Canada.,Clinician Investigator Program, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Nicolle J Domnik
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Kingston Health Sciences Centre & Queen's University, Kingston, ON, Canada
| | - Devin B Phillips
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Kingston Health Sciences Centre & Queen's University, Kingston, ON, Canada
| | - Matthew D James
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Kingston Health Sciences Centre & Queen's University, Kingston, ON, Canada
| | - Sandra G Vincent
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Kingston Health Sciences Centre & Queen's University, Kingston, ON, Canada
| | - J Alberto Neder
- Laboratory of Clinical Exercise Physiology, Division of Respirology, Department of Medicine, Kingston Health Sciences Centre & Queen's University, Kingston, ON, Canada
| | - Denis E O'Donnell
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Kingston Health Sciences Centre & Queen's University, Kingston, ON, Canada
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Camargo PF, Ditomaso-Luporini L, de Carvalho LCS, Goulart CDL, Sebold R, Dos Santos PB, Roscani MG, Borghi-Silva A. Association Between the Predictors of Functional Capacity and Heart Rate Off-Kinetics in Patients with Chronic Obstructive Pulmonary Disease. Int J Chron Obstruct Pulmon Dis 2020; 15:1977-1986. [PMID: 32884254 PMCID: PMC7438181 DOI: 10.2147/copd.s260284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/21/2020] [Indexed: 01/10/2023] Open
Abstract
Background The heart rate (HR) kinetics as well as other predictors of functional capacity such as the Chronic Obstructive Pulmonary Disease (COPD) Assessment Test (CAT), the Duke Activity Status Index (DASI) and the handgrip strength (HGS) represent important tools in assessing the impact of COPD on exercise performance and health status of individuals with COPD. Purpose To verify the relationship between functional capacity, measured using the six-minute walking test (6MWT), with the HR off-kinetics, HGS and the DASI and CAT scores. Methods For this cross-sectional study, 29 subjects with COPD underwent body composition, pulmonary function and cardiac function tests. Subsequently, the DASI and CAT questionnaires and HGS test were performed. The beat-to-beat R-R intervals (IRR) were collected in rest, during the test and in recovery after the 6MWT. The HR off-kinetics was obtained during a 360-second period in post-exercise recovery through the HR mono-exponential decay. Results Moderate correlations were observed between: 1) walked distance (WD) in the 6MWT and the CAT and DASI scores (r= −0.58, p=0.001 and r= 0.58, p=0.001, respectively); 2) WD and HGS (r=0.37, p=0.05); 3) and WD and HR off-kinetics (τ; r= −0.54, p=0.002 and MRT; r= −0.55, p=0.002, respectively). Conclusion The 6MWT performance is a direct measurement to evaluate functional capacity. Additionally, it is related to other direct and indirect markers for functional evaluation in patients with COPD. These results suggest the application of these tools in clinical practice, based on the accessibility, non-invasive character and easy applicability of these methods.
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Affiliation(s)
- Patrícia Faria Camargo
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Sao Paulo, Brazil
| | - Luciana Ditomaso-Luporini
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Sao Paulo, Brazil
| | - Luiz Carlos Soares de Carvalho
- Center for Science and Technology in Energy and Sustainability of Federal University of Reconcavo da Bahia, Feira de Santana, Bahia, Brazil
| | - Cássia da Luz Goulart
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Sao Paulo, Brazil
| | - Rayane Sebold
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Sao Paulo, Brazil.,Course of Physiotherapy, Central Paulista University Center, Sao Carlos, Sao Paulo, Brazil
| | - Polliana Batista Dos Santos
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Sao Paulo, Brazil
| | - Meliza Goi Roscani
- Medicine Department, Federal University of Sao Carlos, Sao Carlos, Sao Paulo, Brazil
| | - Audrey Borghi-Silva
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Sao Paulo, Brazil
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James MD, Milne KM, Phillips DB, Neder JA, O'Donnell DE. Dyspnea and Exercise Limitation in Mild COPD: The Value of CPET. Front Med (Lausanne) 2020; 7:442. [PMID: 32903547 PMCID: PMC7438541 DOI: 10.3389/fmed.2020.00442] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/06/2020] [Indexed: 01/09/2023] Open
Abstract
The majority of smokers with chronic obstructive pulmonary disease (COPD) have mild airflow limitation as determined by simple spirometry. Although small airway dysfunction is the hallmark of COPD, many studies attest to complex heterogeneous physiological impairments beyond increased airway resistance. These impairments are related to inflammation of lung parenchyma and its microvasculature, which is obscured by simple spirometry. Recent studies using advanced radiological imaging have highlighted significant structural abnormalities in smokers with relatively preserved spirometry. These important studies have generated considerable interest and have reinforced the pressing need to better understand the physiological consequences of various morphological abnormalities, and their impact on the clinical outcomes and natural history of COPD. The overarching objective of this review is to provide a concise overview of the importance and utility of cardiopulmonary exercise testing (CPET) in clinical and research settings. CPET uniquely allows evaluation of integrated abnormalities of the respiratory, cardio-circulatory, metabolic, peripheral muscle and neurosensory systems during increases in physiologic stress. This brief review examines the results of recent studies in mild COPD that have uncovered consistent derangements in pulmonary gas exchange and development of “restrictive” dynamic mechanics that together contribute to exercise intolerance. We examine the evidence that compensatory increases in inspiratory neural drive from respiratory control centers are required during exercise in mild COPD to maintain ventilation commensurate with increasing metabolic demand. The ultimate clinical consequences of this high inspiratory neural drive are earlier onset of critical respiratory mechanical constraints and increased perceived respiratory discomfort at relatively low exercise intensities.
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Affiliation(s)
- Matthew D James
- Respiratory Investigation Unit, Department of Medicine, Queen's University, Kingston, ON, Canada
| | - Kathryn M Milne
- Respiratory Investigation Unit, Department of Medicine, Queen's University, Kingston, ON, Canada.,Clinician Investigator Program, University of British Colombia, Vancouver, BC, Canada
| | - Devin B Phillips
- Respiratory Investigation Unit, Department of Medicine, Queen's University, Kingston, ON, Canada
| | - J Alberto Neder
- Laboratory of Clinical and Exercise Physiology, Department of Medicine, Queen's University, Kingston, ON, Canada
| | - Denis E O'Donnell
- Respiratory Investigation Unit, Department of Medicine, Queen's University, Kingston, ON, Canada
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Inspiratory neural drive and dyspnea in interstitial lung disease: Effect of inhaled fentanyl. Respir Physiol Neurobiol 2020; 282:103511. [PMID: 32758677 DOI: 10.1016/j.resp.2020.103511] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 07/03/2020] [Accepted: 07/27/2020] [Indexed: 11/20/2022]
Abstract
BACKGROUND Exertional dyspnea in interstitial lung disease (ILD) remains difficult to manage despite advances in disease-targeted therapies. Pulmonary opioid receptors present a potential therapeutic target for nebulized fentanyl to provide dyspnea relief. METHODS ILD patients were characterized with reference to healthy volunteers. A randomized, double-blind, placebo-controlled crossover comparison of 100 mcg nebulized fentanyl vs placebo on dyspnea intensity and inspiratory neural drive (IND) during constant work rate (CWR) cycle exercise was performed in 21 ILD patients. RESULTS Dyspnea intensity in ILD increased in association with an increase in IND (diaphragm activation) from a high resting value of 16.66 ± 6.52 %-60.04 ± 12.52 % of maximum (r = 0.798, p < 0.001). At isotime during CWR exercise, Borg dyspnea intensity ratings with fentanyl vs placebo were 4.1 ± 1.2 vs 3.8 ± 1.2, respectively (p = 0.174), and IND responses were also similar. CONCLUSION IND rose sharply during constant work rate exercise in association with dyspnea intensity in mild to moderate ILD but was not different after nebulized fentanyl compared with placebo.
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Phillips DB, Collins SÉ, Stickland MK. Measurement and Interpretation of Exercise Ventilatory Efficiency. Front Physiol 2020; 11:659. [PMID: 32714201 PMCID: PMC7344219 DOI: 10.3389/fphys.2020.00659] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/25/2020] [Indexed: 12/19/2022] Open
Abstract
Cardiopulmonary exercise testing (CPET) is a method for evaluating pulmonary and cardiocirculatory abnormalities, dyspnea, and exercise tolerance in healthy individuals and patients with chronic conditions. During exercise, ventilation (V˙E) increases in proportion to metabolic demand [i.e., carbon dioxide production (V˙CO2)] to maintain arterial blood gas and acid-base balance. The response of V˙E relative to V˙CO2 (V˙E/V˙CO2) is commonly termed ventilatory efficiency and is becoming a common physiological tool, in conjunction with other key variables such as operating lung volumes, to evaluate exercise responses in patients with chronic conditions. A growing body of research has shown that the V˙E/V˙CO2 response to exercise is elevated in conditions such as chronic heart failure (CHF), pulmonary hypertension (PH), interstitial lung disease (ILD), and chronic obstructive pulmonary disease (COPD). Importantly, this potentiated V˙E/V˙CO2 response contributes to dyspnea and exercise intolerance. The clinical significance of ventilatory inefficiency is demonstrated by findings showing that the elevated V˙E/V˙CO2 response to exercise is an independent predictor of mortality in patients with CHF, PH, and COPD. In this article, the underlying physiology, measurement, and interpretation of exercise ventilatory efficiency during CPET are reviewed. Additionally, exercise ventilatory efficiency in varying disease states is briefly discussed.
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Affiliation(s)
- Devin B Phillips
- Clinical Physiology Laboratory, Division of Pulmonary Medicine, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada.,Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, AB, Canada
| | - Sophie É Collins
- Clinical Physiology Laboratory, Division of Pulmonary Medicine, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada.,Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada
| | - Michael K Stickland
- Clinical Physiology Laboratory, Division of Pulmonary Medicine, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada.,G.F. MacDonald Centre for Lung Health, Covenant Health, Edmonton, AB, Canada
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Enright P, Fragoso CV. GPs should not try to detect mild COPD. NPJ Prim Care Respir Med 2020; 30:20. [PMID: 32393734 PMCID: PMC7214409 DOI: 10.1038/s41533-020-0176-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 04/07/2020] [Indexed: 11/08/2022] Open
Affiliation(s)
- Paul Enright
- Department of Medicine, the University of Arizona, Tucson, AZ, USA.
| | - Carlos Vaz Fragoso
- Clinical Epidemiology Research Center, VA Connecticut Healthcare System, Mailcode 151B, West Haven, CT, USA.
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Ross BA, Brotto AR, Fuhr DP, Phillips DB, van Diepen S, Bryan TL, Stickland MK. The supine position improves but does not normalize the blunted pulmonary capillary blood volume response to exercise in mild COPD. J Appl Physiol (1985) 2020; 128:925-933. [PMID: 32163328 DOI: 10.1152/japplphysiol.00890.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Patients with mild chronic obstructive pulmonary disease (COPD) demonstrate resting pulmonary vascular dysfunction as well as a blunted pulmonary diffusing capacity (DLCO) and pulmonary capillary blood volume (VC) response to exercise. The transition from the upright to supine position increases central blood volume and perfusion pressure, which may overcome microvascular dysfunction in an otherwise intact alveolar-capillary interface. The present study examined whether the supine position normalized DLCO and VC responses to exercise in mild COPD. Sixteen mild COPD participants and 13 age-, gender-, and height-matched controls completed DLCO maneuvers at rest and during exercise in the upright and supine position. The multiple FIO2-DLCO method was used to determine DLCO, VC, and membrane diffusion capacity (DM). All three variables were adjusted for alveolar volume (DLCOAdj, VCAdj, and DMAdj). The supine position reduced alveolar volume similarly in both groups, but oxygen consumption and cardiac output were unaffected. DLCOAdj, DMAdj, and VCAdj were all lower in COPD. These same variables all increased with upright and supine exercise in both groups. DLCOAdj was unaffected by the supine position. VCAdj increased in the supine position similarly in both groups. DMAdj was reduced in the supine position in both groups. While the supine position increased exercise VCAdj in COPD, the increase was of similar magnitude to healthy controls; therefore, exercise VC remained blunted in COPD. The persistent reduction in exercise DLCO and VC when supine suggests that pulmonary vascular destruction is a contributing factor to the blunted DLCO and VC response to exercise in mild COPD.NEW & NOTEWORTHY Patients with mild chronic obstructive pulmonary disease demonstrate a combination of reversible pulmonary microvascular dysfunction and irreversible pulmonary microvascular destruction.
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Affiliation(s)
- Bryan A Ross
- Faculty of Medicine and Dentistry, Division of Pulmonary Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Andrew R Brotto
- Faculty of Medicine and Dentistry, Division of Pulmonary Medicine, University of Alberta, Edmonton, Alberta, Canada.,Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Desi P Fuhr
- Faculty of Medicine and Dentistry, Division of Pulmonary Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Devin B Phillips
- Faculty of Medicine and Dentistry, Division of Pulmonary Medicine, University of Alberta, Edmonton, Alberta, Canada.,Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Sean van Diepen
- Faculty of Medicine and Dentistry, Division of Cardiology, Department of Critical Care, University of Alberta, Edmonton, Alberta, Canada
| | - Tracey L Bryan
- Faculty of Medicine and Dentistry, Division of Pulmonary Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Michael K Stickland
- Faculty of Medicine and Dentistry, Division of Pulmonary Medicine, University of Alberta, Edmonton, Alberta, Canada.,G.F. MacDonald Centre for Lung Health, Covenant Health, Edmonton, Alberta, Canada
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de Carvalho Junior LCS, Trimer R, Zangrando KL, Arêas GPT, Caruso FR, Bonjorno Junior JC, Oliveira CR, Mendes R, Borghi-Silva A. Overlap syndrome: the coexistence of OSA further impairs cardiorespiratory fitness in COPD. Sleep Breath 2020; 24:1451-1462. [PMID: 31898188 DOI: 10.1007/s11325-019-02002-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 12/11/2019] [Accepted: 12/18/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Cardiorespiratory fitness (CRF) is an important prognostic marker in chronic obstructive pulmonary disease (COPD). Obstructive sleep apnea (OSA) also negatively affects exercise tolerance. However, the impact of their association on CRF has not been evaluated. We hypothesized that patients with overlap syndrome would demonstrate a greater impairment in CRF, particularly those with severe COPD. METHODS Individuals with COPD were recruited. First, subjects underwent clinical and spirometry evaluation. Next, home-based sleep evaluation was performed. Subjects with an apnea-hypopnea index (AHI) < 15 episodes/h were allocated to the COPD group and those with an AHI ≥ 15 episodes/h to the overlap group. On the second visit, subjects underwent a cardiopulmonary exercise test. Subsequently, they were divided into four groups according to the severity of COPD and coexistence of OSA: COPDI/II; overlap I/II; COPDIII/IV; and overlap III/IV. RESULTS Of the 268 subjects screened, 31 were included. The overlap group exhibited higher values for peak carbon dioxide (COPD: 830 [678-1157]; overlap: 1127 [938-1305] mm Hg; p < 0.05), minute ventilation (COPD: 31 [27-45]; overlap: 48 [37-55] L; p < 0.05), and peak systolic blood pressure (COPD: 180 [169-191]; overlap: 220 [203-227] mm Hg; p <; 0.001) and peak diastolic blood pressure COPD: 100 [93-103]; overlap: 110 [96-106] mm Hg; p < 0.001). COPD severity associated with OSA produced a negative impact on exercise time (COPDIII/IV: 487 ± 102; overlap III/IV: 421 ± 94 s), peak oxygen uptake (COPDIII/IV: 12 ± 2; overlap III/IV: 9 ± 1 ml.Kg.min-1 ; p < 0.05) and circulatory power (COPDIII/IV: 2306 ± 439; overlap III/IV: 2162 ± 340 ml/kg/min.mmHg; p < 0.05). CONCLUSION Overlap syndrome causes greater hemodynamic and ventilatory demand at the peak of dynamic exercise. In addition, OSA overlap in individuals with more severe COPD impairs CRF.
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Affiliation(s)
| | - Renata Trimer
- University of Santa Cruz do Sul, Santa Cruz do Sul, Brazil
| | - Katiany Lopes Zangrando
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Rodovia Washington Luis, KM 235, Monjolinho, São Carlos, SP, 13565-905, Brazil
| | | | - Flávia Rossi Caruso
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Rodovia Washington Luis, KM 235, Monjolinho, São Carlos, SP, 13565-905, Brazil
| | | | | | - Renata Mendes
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Rodovia Washington Luis, KM 235, Monjolinho, São Carlos, SP, 13565-905, Brazil
| | - Audrey Borghi-Silva
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Rodovia Washington Luis, KM 235, Monjolinho, São Carlos, SP, 13565-905, Brazil.
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Fallahtafti F, Curtze C, Samson K, Yentes JM. Chronic obstructive pulmonary disease patients increase medio-lateral stability and limit changes in antero-posterior stability to curb energy expenditure. Gait Posture 2020; 75:142-148. [PMID: 31683184 PMCID: PMC6889081 DOI: 10.1016/j.gaitpost.2019.10.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 10/09/2019] [Accepted: 10/16/2019] [Indexed: 02/02/2023]
Abstract
BACKGROUND A relationship exists between step width and energy expenditure, yet the contribution of dynamic stability to energy expenditure is not completely understood. Chronic obstructive pulmonary disease (COPD) patients' energy expenditure is increased due to airway obstruction. Further, they have a higher prevalence of falls and balance deficits compared to controls. RESEARCH QUESTION Is dynamic stability different between COPD patients and controls; and is the association between dynamic stability and energy expenditure different between groups? METHODS Seventeen COPD patients (64.3 ± 7.6years) and 23 controls (59.9 ± 6.6years) walked on a treadmill at three speeds: self-selected walking speed (SSWS), -20%SSWS, and +20%SSWS. Mean and variability (standard deviation) of the anterior-posterior (AP) and medio-lateral (ML) margins of stability (MOS) were compared between groups and speed conditions, while controlling for covariates. Additionally, their association to metabolic power was examined. RESULTS The association between stability and power did not significantly differ between groups. However, increased metabolic power was associated with decreased MOS AP mean (p < 0.0001), independent of speed. Increased MOS AP variability (p = 0.01) and increased SSWS (p's < 0.05) were associated with increased metabolic power. The MOS ML mean for COPD patients was greater than that of healthy patients (p = 0.02). MOS AP mean decreased as speed increased and differed by group (p = 0.048). For COPD patients, a plateau was observed at SSWS and did not decrease further at +20%SSWS compared to controls. MOS AP variability (p < 0.0001), MOS ML mean (p < 0.0001), and MOS ML variability (p = 0.003) decreased as speed increased and did not differ by group. SIGNIFICANCE Patients with COPD operate at the upper limit of their metabolic reserve due to an increased cost of breathing. To compensate for their lack of stability, they walked with larger margins of stability in the ML direction, instead of changing the stability margins in the AP direction, due to its association with energy expenditure.
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Affiliation(s)
- Farahnaz Fallahtafti
- Department of Biomechanics, University of Nebraska at Omaha, 6160 University Drive South, Omaha, NE 68182-0860, United States.
| | - Carolin Curtze
- Department of Biomechanics, University of Nebraska at Omaha, 6160 University Drive South, Omaha, NE 68182-0860, United States.
| | - Kaeli Samson
- Department of Biostatistics, University of Nebraska Medical Center, 984375 Nebraska Medical Center, Omaha, NE 68198-4375, United States.
| | - Jennifer M Yentes
- Department of Biomechanics, University of Nebraska at Omaha, 6160 University Drive South, Omaha, NE 68182-0860, United States.
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O'Donnell DE, Milne KM, James MD, de Torres JP, Neder JA. Dyspnea in COPD: New Mechanistic Insights and Management Implications. Adv Ther 2020; 37:41-60. [PMID: 31673990 PMCID: PMC6979461 DOI: 10.1007/s12325-019-01128-9] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Indexed: 12/29/2022]
Abstract
Dyspnea is the most common symptom experienced by patients with chronic obstructive pulmonary disease (COPD). To avoid exertional dyspnea, many patients adopt a sedentary lifestyle which predictably leads to extensive skeletal muscle deconditioning, social isolation, and its negative psychological sequalae. This "dyspnea spiral" is well documented and it is no surprise that alleviation of this distressing symptom has become a key objective highlighted across COPD guidelines. In reality, this important goal is often difficult to achieve, and successful symptom management awaits a clearer understanding of the underlying mechanisms of dyspnea and how these can be therapeutically manipulated for the patients' benefit. Current theoretical constructs of the origins of activity-related dyspnea generally endorse the classical demand-capacity imbalance theory. Thus, it is believed that disruption of the normally harmonious relationship between inspiratory neural drive (IND) to breathe and the simultaneous dynamic response of the respiratory system fundamentally shapes the expression of respiratory discomfort in COPD. Sadly, the symptom of dyspnea cannot be eliminated in patients with advanced COPD with relatively fixed pathophysiological impairment. However, there is evidence that effective symptom palliation is possible for many. Interventions that reduce IND, without compromising alveolar ventilation (VA), or that improve respiratory mechanics and muscle function, or that address the affective dimension, achieve measurable benefits. A common final pathway of dyspnea relief and improved exercise tolerance across the range of therapeutic interventions (bronchodilators, exercise training, ambulatory oxygen, inspiratory muscle training, and opiate medications) is reduced neuromechanical dissociation of the respiratory system. These interventions, singly and in combination, partially restore more harmonious matching of excessive IND to ventilatory output achieved. In this review we propose, on the basis of a thorough review of the recent literature, that effective dyspnea amelioration requires combined interventions and a structured multidisciplinary approach, carefully tailored to meet the specific needs of the individual.
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Affiliation(s)
- Denis E O'Donnell
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Kingston Health Sciences Centre and Queen's University, Kingston, ON, Canada.
| | - Kathryn M Milne
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Kingston Health Sciences Centre and Queen's University, Kingston, ON, Canada
- Clinician Investigator Program, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Matthew D James
- Respiratory Investigation Unit, Division of Respirology, Department of Medicine, Kingston Health Sciences Centre and Queen's University, Kingston, ON, Canada
| | - Juan Pablo de Torres
- Division of Respirology, Department of Medicine, Kingston Health Sciences Centre and Queen's University, Kingston, ON, Canada
| | - J Alberto Neder
- Division of Respirology, Department of Medicine, Kingston Health Sciences Centre and Queen's University, Kingston, ON, Canada
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Phillips DB, Collins SÉ, Bryan TL, Wong EYL, McMurtry MS, Bhutani M, Stickland MK. The effect of carotid chemoreceptor inhibition on exercise tolerance in chronic obstructive pulmonary disease: A randomized-controlled crossover trial. Respir Med 2019; 160:105815. [PMID: 31739245 DOI: 10.1016/j.rmed.2019.105815] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 10/24/2019] [Accepted: 11/05/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND Patients with chronic obstructive pulmonary disease (COPD) have an exaggerated ventilatory response to exercise, contributing to exertional dyspnea and exercise intolerance. We recently demonstrated enhanced activity and sensitivity of the carotid chemoreceptor (CC) in COPD which may alter ventilatory and cardiovascular regulation and negatively affect exercise tolerance. We sought to determine whether CC inhibition improves ventilatory and cardiovascular regulation, dyspnea and exercise tolerance in COPD. METHODS Twelve mild-moderate COPD patients (FEV1 83 ± 15 %predicted) and twelve age- and sex-matched healthy controls completed two time-to-symptom limitation (TLIM) constant load exercise tests at 75% peak power output with either intravenous saline or low-dose dopamine (2 μg·kg-1·min-1, order randomized) to inhibit the CC. Ventilatory responses were evaluated using expired gas data and dyspnea was evaluated using a modified Borg scale. Inspiratory capacity maneuvers were performed to determine operating lung volumes. Cardiac output was estimated using impedance cardiography and vascular conductance was calculated as cardiac output/mean arterial pressure (MAP). RESULTS At a standardized exercise time of 4-min and at TLIM; ventilation, operating volumes and dyspnea were unaffected by dopamine in COPD patients and controls. In COPD, dopamine decreased MAP and increased vascular conductance at all time points. In controls, dopamine increased vascular conductance at TLIM, while MAP was unaffected. CONCLUSION There was no change in time to exhaustion in either group with dopamine. These data suggest that the CC plays a role in cardiovascular regulation during exercise in COPD; however, ventilation, dyspnea and exercise tolerance were unaffected by CC inhibition in COPD patients.
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Affiliation(s)
- Devin B Phillips
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Canada; Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Canada
| | - Sophie É Collins
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Canada; Faculty of Rehabilitation Medicine, University of Alberta, Canada
| | - Tracey L Bryan
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Canada
| | - Eric Y L Wong
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Canada
| | - M Sean McMurtry
- Division of Cardiology, Faculty of Medicine and Dentistry, University of Alberta, Canada
| | - Mohit Bhutani
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Canada
| | - Michael K Stickland
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Canada; G.F. MacDonald Centre for Lung Health, Covenant Health, Edmonton, Alberta, Canada.
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Singh D, D'Urzo AD, Donohue JF, Kerwin EM. Weighing the evidence for pharmacological treatment interventions in mild COPD; a narrative perspective. Respir Res 2019; 20:141. [PMID: 31286970 PMCID: PMC6615221 DOI: 10.1186/s12931-019-1108-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 06/24/2019] [Indexed: 12/15/2022] Open
Abstract
There is increasing focus on understanding the nature of chronic obstructive pulmonary disease (COPD) during the earlier stages. Mild COPD (Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage 1 or the now-withdrawn GOLD stage 0) represents an early stage of COPD that may progress to more severe disease. This review summarises the disease burden of patients with mild COPD and discusses the evidence for treatment intervention in this subgroup. Overall, patients with mild COPD suffer a substantial disease burden that includes persistent or potentially debilitating symptoms, increased risk of exacerbations, increased healthcare utilisation, reduced exercise tolerance and physical activity, and a higher rate of lung function decline versus controls. However, the evidence for treatment efficacy in these patients is limited due to their frequent exclusion from clinical trials. Careful assessment of disease burden and the rate of disease progression in individual patients, rather than a reliance on spirometry data, may identify patients who could benefit from earlier treatment intervention.
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Affiliation(s)
- Dave Singh
- University of Manchester, Medicines Evaluation Unit, Manchester University NHS Foundation Trust, Manchester, M23 9QZ, UK.
| | - Anthony D D'Urzo
- Department of Family and Community Medicine, University of Toronto, Toronto, Ontario, Canada
| | - James F Donohue
- Division of Pulmonary Diseases & Critical Care Medicine, University of North Carolina Pulmonary Critical Medicine, Chapel Hill, North Carolina, USA
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O’Donnell DE, Milne KM, Vincent SG, Neder JA. Unraveling the Causes of Unexplained Dyspnea. Clin Chest Med 2019; 40:471-499. [DOI: 10.1016/j.ccm.2019.02.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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O’Donnell DE, James MD, Milne KM, Neder JA. The Pathophysiology of Dyspnea and Exercise Intolerance in Chronic Obstructive Pulmonary Disease. Clin Chest Med 2019; 40:343-366. [DOI: 10.1016/j.ccm.2019.02.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Hanania NA, O'Donnell DE. Activity-related dyspnea in chronic obstructive pulmonary disease: physical and psychological consequences, unmet needs, and future directions. Int J Chron Obstruct Pulmon Dis 2019; 14:1127-1138. [PMID: 31213793 PMCID: PMC6538882 DOI: 10.2147/copd.s188141] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 04/01/2019] [Indexed: 12/27/2022] Open
Abstract
Dyspnea is a distressing, debilitating, and near-ubiquitous symptom affecting patients with COPD. In addition to the functional consequences of dyspnea, which include activity limitation and reduced exercise tolerance, it is important to consider its psychological impact on patients with COPD, such as onset of depression or anxiety. Moreover, the anticipation of dyspnea itself can have a significant effect on patients' emotions and behavior, with patients frequently self-limiting physical activity to avoid what has become the hallmark symptom of COPD. Dyspnea is, therefore, a key target for COPD treatments. Pharmacologic treatments can optimize respiratory mechanics, provide symptom relief, and reduce patients' increased inspiratory neural drive to breathe. However, it is important to acknowledge the value of non-pharmacologic interventions, such as pulmonary rehabilitation and patient self-management education, which have proven to be invaluable tools for targeting the affective components of dyspnea. Furthermore, it is important to encourage maintenance of physical activity to optimize long-term patient outcomes. Here, we review the physiological and psychological consequences of activity-related dyspnea in COPD, assess the efficacy of modern management strategies in improving this common respiratory symptom, and discuss key unmet clinical and research needs that warrant further immediate attention.
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Affiliation(s)
- Nicola A Hanania
- Department of Medicine, Section of Pulmonary and Critical Care, Baylor College of Medicine, Houston, TX, USA
| | - Denis E O'Donnell
- Division of Respirology, Department of Medicine, Queen's University, Kingston, Ontario, Canada
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