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Balasubramanian A, Wise RA, Stanojevic S, Miller MR, McCormack MC. FEV 1Q: a race-neutral approach to assessing lung function. Eur Respir J 2024; 63:2301622. [PMID: 38485146 PMCID: PMC11027150 DOI: 10.1183/13993003.01622-2023] [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] [Received: 09/22/2023] [Accepted: 02/19/2024] [Indexed: 03/23/2024]
Abstract
BACKGROUND Forced expiratory volume in 1 s quotient (FEV1Q) is a simple approach to spirometry interpretation that compares measured lung function to a lower boundary. This study evaluated how well FEV1Q predicts survival compared with current interpretation methods and whether race impacts FEV1Q. METHODS White and Black adults with complete spirometry and mortality data from the National Health and Nutrition Examination Survey (NHANES) III and the United Network for Organ Sharing (UNOS) database for lung transplant referrals were included. FEV1Q was calculated as FEV1 divided by 0.4 L for females or 0.5 L for males. Cumulative distributions of FEV1 were compared across races. Cox proportional hazards models tested mortality risk from FEV1Q adjusting for age, sex, height, smoking, income and among UNOS individuals, referral diagnosis. Harrell's C-statistics were compared between absolute FEV1, FEV1Q, FEV1/height2, FEV1 z-scores and FEV1 % predicted. Analyses were stratified by race. RESULTS Among 7182 individuals from NHANES III and 7149 from UNOS, 1907 (27%) and 991 (14%), respectively, were Black. The lower boundary FEV1 values did not differ between Black and White individuals in either population (FEV1 first percentile difference ≤0.01 L; p>0.05). Decreasing FEV1Q was associated with increasing hazard ratio (HR) for mortality (NHANES III HR 1.33 (95% CI 1.28-1.39) and UNOS HR 1.18 (95% CI 1.12-1.23)). The associations were not confounded nor modified by race. Discriminative power was highest for FEV1Q compared with alternative FEV1 approaches in both Black and White individuals. CONCLUSIONS FEV1Q is an intuitive and simple race-neutral approach to interpreting FEV1 that predicts survival better than current alternative methods.
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Affiliation(s)
- Aparna Balasubramanian
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Robert A Wise
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Sanja Stanojevic
- Department of Community Health and Epidemiology, Dalhousie University, Halifax, NS, Canada
| | - Martin R Miller
- Institute of Applied Health Sciences, University of Birmingham, Birmingham, UK
| | - Meredith C McCormack
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
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Aboelhassan A, Hurst JR. FEV 1Q: what (even) is normal lung function? Eur Respir J 2024; 63:2400354. [PMID: 38575165 DOI: 10.1183/13993003.00354-2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 03/10/2024] [Indexed: 04/06/2024]
Affiliation(s)
- Arafa Aboelhassan
- Chest Department, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - John R Hurst
- UCL Respiratory, University College London, London, UK
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Chuang ML, Wang YH, Lin IF. The contribution of estimated dead space fraction to mortality prediction in patients with chronic obstructive pulmonary disease-a new proposal. PeerJ 2024; 12:e17081. [PMID: 38560478 PMCID: PMC10981412 DOI: 10.7717/peerj.17081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 02/19/2024] [Indexed: 04/04/2024] Open
Abstract
Background Mortality due to chronic obstructive pulmonary disease (COPD) is increasing. However, dead space fractions at rest (VD/VTrest) and peak exercise (VD/VTpeak) and variables affecting survival have not been evaluated. This study aimed to investigate these issues. Methods This retrospective observational cohort study was conducted from 2010-2020. Patients with COPD who smoked, met the Global Initiatives for Chronic Lung Diseases (GOLD) criteria, had available demographic, complete lung function test (CLFT), medication, acute exacerbation of COPD (AECOPD), Charlson Comorbidity Index, and survival data were enrolled. VD/VTrest and VD/VTpeak were estimated (estVD/VTrest and estVD/VTpeak). Univariate and multivariable Cox regression with stepwise variable selection were performed to estimate hazard ratios of all-cause mortality. Results Overall, 14,910 patients with COPD were obtained from the hospital database, and 456 were analyzed after excluding those without CLFT or meeting the lung function criteria during the follow-up period (median (IQR) 597 (331-934.5) days). Of the 456 subjects, 81% had GOLD stages 2 and 3, highly elevated dead space fractions, mild air-trapping and diffusion impairment. The hospitalized AECOPD rate was 0.60 ± 2.84/person/year. Forty-eight subjects (10.5%) died, including 30 with advanced cancer. The incidence density of death was 6.03 per 100 person-years. The crude risk factors for mortality were elevated estVD/VTrest, estVD/VTpeak, ≥2 hospitalizations for AECOPD, advanced age, body mass index (BMI) <18.5 kg/m2, and cancer (hazard ratios (95% C.I.) from 1.03 [1.00-1.06] to 5.45 [3.04-9.79]). The protective factors were high peak expiratory flow%, adjusted diffusing capacity%, alveolar volume%, and BMI 24-26.9 kg/m2. In stepwise Cox regression analysis, after adjusting for all selected factors except cancer, estVD/VTrest and BMI <18.5 kg/m2 were risk factors, whereas BMI 24-26.9 kg/m2 was protective. Cancer was the main cause of all-cause mortality in this study; however, estVD/VTrest and BMI were independent prognostic factors for COPD after excluding cancer. Conclusions The predictive formula for dead space fraction enables the estimation of VD/VTrest, and the mortality probability formula facilitates the estimation of COPD mortality. However, the clinical implications should be approached with caution until these formulas have been validated.
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Affiliation(s)
- Ming-Lung Chuang
- School of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Div. Pulmonary Medicine, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Yu Hsun Wang
- Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - I-Feng Lin
- Institute of Public Health, National Yang Ming Chiao Tung University, Taipei, Taiwan
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da Silva Alves C, Barroso T, Gerardo A, Almeida T, Maduro S, Boléo-Tomé JP, Liberato H. Forced Expiratory Volume in One Second Quotient (FEV1Q) as a Prognostic Factor in Amyotrophic Lateral Sclerosis Patients: Comparing Its Predictive Value to Other Lung Function Measurements. Cureus 2024; 16:e54176. [PMID: 38496202 PMCID: PMC10941708 DOI: 10.7759/cureus.54176] [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] [Accepted: 02/12/2024] [Indexed: 03/19/2024] Open
Abstract
INTRODUCTION Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting the first and second motor neurons. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) have conventionally served as indicators of respiratory muscle strength. Recently, FEV1Q (FEV1 divided by the sex-specific first percentile values of absolute FEV1 in adults with lung disease) has been suggested as a predictor of mortality. While FVC has been utilized as a prognostic factor, FEV1Q has not yet been examined. METHODS This retrospective unicenter study evaluated FEV1Q as a predictor of mortality in ALS patients, comparing its predictive efficacy with other measurements, including FEV1, FVC, sniff nasal inspiratory pressure, and maximal inspiratory pressure. The study utilized univariate analysis for each variable employing the Cox proportional hazards model to determine the statistical significance and predictive power of each measurement. RESULTS Forty-five patients were included, female predominant (60%) and an average age at diagnosis of 69.2 ± 11 years. Almost all (95%) met the criteria for non-invasive ventilation (NIV) and initiated (93%) during the study period, a mean of 137 days after diagnosis. The mortality rate observed was 57%, occurring at a median of 398 days post-diagnosis. On average, patients underwent 1.7 pulmonary function tests, revealing a decline in various parameters, including FEV1, FEV1Q, and FVC. However, only FEV1Q was a statistically significant predictor of mortality (p < 0.0083) in a Cox regression analysis. A negative coefficient for FEV1Q indicated that higher values were associated with a reduced mortality risk, with an average FEV1Q of 2.68 observed at the time of death. CONCLUSION FEV1Q emerged as the only statistically significant predictor of mortality among the evaluated respiratory measurements in ALS patients. This study is the first to focus on applying FEV1Q in the clinical evaluation of ALS, marking an initial step in understanding its potential role in patient follow-up. However, further studies are needed before these findings can be incorporated into clinical practice.
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Affiliation(s)
| | - Tiago Barroso
- Medical Oncology Department, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisboa, PRT
| | - António Gerardo
- Pulmonology Department, Hospital Professor Doutor Fernando Fonseca, Amadora, PRT
| | - Tânia Almeida
- Pulmonology Department, Hospital Professor Doutor Fernando Fonseca, Amadora, PRT
| | - Silvia Maduro
- Pulmonology Department, Hospital Professor Doutor Fernando Fonseca, Amadora, PRT
| | | | - Hedi Liberato
- Pulmonology Department, Hospital Professor Doutor Fernando Fonseca, Amadora, PRT
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Kim YS, Hwang YI, Lee JH, Park YB, Choi CW, Jung KS, Yoo KH, Lim SY, Kim JS, Choi JY. Clinical significance of normalized airflow obstruction in patients with chronic obstructive pulmonary disease. Respir Med 2023; 218:107398. [PMID: 37659437 DOI: 10.1016/j.rmed.2023.107398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 08/17/2023] [Accepted: 08/25/2023] [Indexed: 09/04/2023]
Abstract
BACKGROUND There is ongoing debate regarding the diagnostic criteria for chronic obstructive pulmonary disease (COPD); recent studies have focused on the early COPD detection and management. Here, we compared clinical features and prognosis in patients with FEV1/FVC<0.70 at baseline, according to normalized airflow obstruction status during follow-up. METHODS We used the Korea COPD Subgroup Study (KOCOSS) cohort database, a prospective nationwide observational COPD study. Normalized obstruction (NO) was defined as FEV1/FVC ≥0.7 in the 2-year follow-up period, whereas fixed obstruction (FO) was defined as FEV1/FVC <0.7. Demographic and clinical data, 1-year exacerbation risk and difference in FEV1 decline over 2 years were compared between NO and FO groups. RESULTS Among the 670 COPD patients with post-bronchodilator FEV1/FVC <0.7 in this study, 95 (14.2%) displayed NO. Compared with the FO group, the NO group had higher FEV1, and DLCO, body mass index, as well as lower Saint George Respiratory Questionnaire, Beck Depression Index, and Beck Anxiety Index. Blood eosinophil count, IgE level, and FeNO did not significantly differ between two groups. There was no significant difference in exacerbation frequency between the two groups, but the NO group had a significant increase in FEV1 compared with the FO group during follow-up. CONCLUSION Transient airflow obstruction in the NO group may represent a clinical manifestation of early COPD; close monitoring is needed for such patients.
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Affiliation(s)
- Yun Seok Kim
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Yong Il Hwang
- Department of Internal Medicine, College of Medicine, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea
| | - Jae Ha Lee
- Department of Internal Medicine, Haeundae Paik Hospital, Inje University College of Medicine, Busan, 135-710, South Korea
| | - Yong Bum Park
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Gangdong Sacred Heart Hospital, The Hallym University, South Korea
| | - Cheon Woong Choi
- Department of Pulmonary, Allergy and Critical Care Medicine, Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea
| | - Ki-Suck Jung
- Department of Internal Medicine, College of Medicine, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea
| | - Kwang Ha Yoo
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Seong Yong Lim
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Ju Sang Kim
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Joon Young Choi
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
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Chuang ML, Wang YH. Tidal volume expandability and ventilatory efficiency as predictors of mortality in Taiwanese male patients with chronic obstructive pulmonary disease: A 10-year follow-up study - Is V̇O 2peak or FEV 1% the gold standard? Chron Respir Dis 2023; 20:14799731231220675. [PMID: 38086393 PMCID: PMC10722945 DOI: 10.1177/14799731231220675] [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: 07/19/2023] [Accepted: 11/21/2023] [Indexed: 12/17/2023] Open
Abstract
Despite our knowledge of the risk factors for mortality associated with chronic obstructive pulmonary disease (COPD), the mortality rate for this condition continues to increase. This study aimed to investigate the predictive power of physiological variables on all-cause mortality in COPD patients compared to peak oxygen uptake (V ˙ O2peak) and forced expired volume in one second (FEV1). We conducted a retrospective study of 182 COPD patients with complete lung function tests, cardiopulmonary exercise testing (CPET), and survival data. Cox regression analysis was used to estimate the hazard ratios for all-cause mortality. The median follow-up period was 6.8 (IQR 3.9-9.2) years. Out of the 182 patients in our study, sixty-two (34.1%) succumbed to various causes. Of these, 27.4% (n = 17) experienced acute exacerbations, 24.2% (n = 15) had advanced cancer, and 12.9% (n = 8) had cardiovascular disease as the primary cause of death. Another 25.8% (n = 16) passed away due to other underlying conditions, while 6.5% (n = 4) had an unknown cause of death. One patient's demise was attributed to a benign tumor, and another's to a connective tissue disease. The ratio of tidal volume to total lung capacity (VTpeak/TLC) and the ratio of minute ventilation and V ˙ O2 at nadir (V ˙ E/V ˙ O2nadir) (AUR 0.83, 95% CI 0.76-0.91) were superior predictors of all-cause mortality compared to V ˙ O2peak and FEV1%. A mortality prediction formula was derived using these variables. This study highlights the potential of VTpeak/TLC and V ˙ E/V ˙ O2nadir as predictive markers for COPD all-cause mortality in COPD. CPET is an effective tool for evaluating COPD mortality; however, the predictive equation requires further validation.
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Affiliation(s)
- Ming-Lung Chuang
- Division of Pulmonary Medicine and Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan
- School of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Yu-Hsun Wang
- Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan
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7
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Chuang ML. Hierarchical stratification of the factors related to exertional dyspnoea and exercise intolerance in male COPD patients. Ann Med 2022; 54:2941-2950. [PMID: 36314466 PMCID: PMC9629069 DOI: 10.1080/07853890.2022.2135018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND The order and extent of interactions across the factors affecting exertional dyspnoea (ED) and exercise intolerance (EI) in patients with chronic obstructive pulmonary disease (COPD) are not clear. We hypothesized that lung and non-lung variables were the primary variables, ED was the secondary variable and EI was the tertiary variable. METHODS Data on demographics, blood tests, cardiac imaging, lung function tests and invasive dead space fractions (VD/VT) during incremental exercise test of 46 male COPD subjects were obtained. These variables were categorized by factor analysis and pair-wise correlation analysis was conducted. The best factor of each category was selected and then multivariate regression was conducted. RESULTS Peak tidal inspiratory flow (VT/TIpeak), VD/VTpeak and tidal lung expansion capability, and resting diffusing capacity of the lungs (DLCO)% predicted were the primary pulmonary factors most related to ED, whereas body mass index (BMI), haemoglobin and cholesterol levels were the primary non-pulmonary factors. In multivariate regression analysis, VT/TIpeak, VD/VTpeak and DLCO% were the primary factors most related to ED (r2 = 0.69); ED was most related to EI (r = -0.74 to -0.83). CONCLUSION Using hierarchical stratification and statistical methods may improve understanding of the pathophysiology of ED and EI in patients with COPD. KEY MESSAGESThe pathophysiology of exertional dyspnoea (ED) and exercise intolerance (EI) in chronic obstructive pulmonary disease (COPD) is complex. The order and extent of interactions across factors are not clear. In multivariate regression analysis, we found that tidal inspiratory flow, dead space fraction and resting diffusing capacity of the lungs % but not the non-pulmonary factors affected ED.Using correlation coefficients, we further found that ED was the secondary variable and EI was the tertiary variable.Hierarchical stratification of the important factors associated with ED and EI in patients with COPD clarifies their relationships and could be incorporated into management programmes and outcome studies for these patients.
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Affiliation(s)
- Ming-Lung Chuang
- Department of Internal Medicine, Division of Pulmonary Medicine, Chung Shan Medical University Hospital, Taichung, ROC.,School of Medicine, Chung Shan Medical University, Taichung, ROC
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8
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Wei D, Wang Q, Liu S, Tan X, Chen L, Tu R, Liu Q, Jia Y, Liu S. Influences of Two FEV1 Reference Equations (GLI-2012 and GIRH-2017) on Airflow Limitation Classification Among COPD Patients. Int J Chron Obstruct Pulmon Dis 2022; 17:2053-2065. [PMID: 36081764 PMCID: PMC9447406 DOI: 10.2147/copd.s373834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 08/17/2022] [Indexed: 11/23/2022] Open
Abstract
Objective Methods Results Conclusion
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Affiliation(s)
- Dafei Wei
- Department of Pediatrics, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, People’s Republic of China
| | - Qi Wang
- Department of Pulmonary and Critical Care Medicine, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, People’s Republic of China
| | - Shasha Liu
- Department of Pulmonary and Critical Care Medicine, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, People’s Republic of China
| | - Xiaowu Tan
- Department of Pulmonary and Critical Care Medicine, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, People’s Republic of China
| | - Lin Chen
- Department of Pulmonary and Critical Care Medicine, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, People’s Republic of China
| | - Rongfang Tu
- Department of Pulmonary and Critical Care Medicine, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, People’s Republic of China
| | - Qing Liu
- Department of Pulmonary and Critical Care Medicine, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, People’s Republic of China
| | - Yuanhang Jia
- Department of Pulmonary and Critical Care Medicine, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, People’s Republic of China
| | - Sha Liu
- Department of Pulmonary and Critical Care Medicine, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, People’s Republic of China
- Correspondence: Sha Liu, Department of Pulmonary and Critical Care Medicine, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, People’s Republic of China, Email
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Hurst JR, Han MK, Singh B, Sharma S, Kaur G, de Nigris E, Holmgren U, Siddiqui MK. Prognostic risk factors for moderate-to-severe exacerbations in patients with chronic obstructive pulmonary disease: a systematic literature review. Respir Res 2022; 23:213. [PMID: 35999538 PMCID: PMC9396841 DOI: 10.1186/s12931-022-02123-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 07/20/2022] [Indexed: 11/30/2022] Open
Abstract
Background Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. COPD exacerbations are associated with a worsening of lung function, increased disease burden, and mortality, and, therefore, preventing their occurrence is an important goal of COPD management. This review was conducted to identify the evidence base regarding risk factors and predictors of moderate-to-severe exacerbations in patients with COPD. Methods A literature review was performed in Embase, MEDLINE, MEDLINE In-Process, and the Cochrane Central Register of Controlled Trials (CENTRAL). Searches were conducted from January 2015 to July 2019. Eligible publications were peer-reviewed journal articles, published in English, that reported risk factors or predictors for the occurrence of moderate-to-severe exacerbations in adults age ≥ 40 years with a diagnosis of COPD. Results The literature review identified 5112 references, of which 113 publications (reporting results for 76 studies) met the eligibility criteria and were included in the review. Among the 76 studies included, 61 were observational and 15 were randomized controlled clinical trials. Exacerbation history was the strongest predictor of future exacerbations, with 34 studies reporting a significant association between history of exacerbations and risk of future moderate or severe exacerbations. Other significant risk factors identified in multiple studies included disease severity or bronchodilator reversibility (39 studies), comorbidities (34 studies), higher symptom burden (17 studies), and higher blood eosinophil count (16 studies). Conclusions This systematic literature review identified several demographic and clinical characteristics that predict the future risk of COPD exacerbations. Prior exacerbation history was confirmed as the most important predictor of future exacerbations. These prognostic factors may help clinicians identify patients at high risk of exacerbations, which are a major driver of the global burden of COPD, including morbidity and mortality. Supplementary Information The online version contains supplementary material available at 10.1186/s12931-022-02123-5.
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Affiliation(s)
- John R Hurst
- UCL Respiratory, University College London, London, WC1E 6BT, UK.
| | - MeiLan K Han
- Division of Pulmonary and Critical Care, University of Michigan, Ann Arbor, MI, USA
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Stanojevic S, Kaminsky DA, Miller MR, Thompson B, Aliverti A, Barjaktarevic I, Cooper BG, Culver B, Derom E, Hall GL, Hallstrand TS, Leuppi JD, MacIntyre N, McCormack M, Rosenfeld M, Swenson ER. ERS/ATS technical standard on interpretive strategies for routine lung function tests. Eur Respir J 2022; 60:2101499. [PMID: 34949706 DOI: 10.1183/13993003.01499-2021] [Citation(s) in RCA: 345] [Impact Index Per Article: 172.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 11/18/2021] [Indexed: 01/21/2023]
Abstract
BACKGROUND Appropriate interpretation of pulmonary function tests (PFTs) involves the classification of observed values as within/outside the normal range based on a reference population of healthy individuals, integrating knowledge of physiological determinants of test results into functional classifications and integrating patterns with other clinical data to estimate prognosis. In 2005, the American Thoracic Society (ATS) and European Respiratory Society (ERS) jointly adopted technical standards for the interpretation of PFTs. We aimed to update the 2005 recommendations and incorporate evidence from recent literature to establish new standards for PFT interpretation. METHODS This technical standards document was developed by an international joint Task Force, appointed by the ERS/ATS with multidisciplinary expertise in conducting and interpreting PFTs and developing international standards. A comprehensive literature review was conducted and published evidence was reviewed. RESULTS Recommendations for the choice of reference equations and limits of normal of the healthy population to identify individuals with unusually low or high results are discussed. Interpretation strategies for bronchodilator responsiveness testing, limits of natural changes over time and severity are also updated. Interpretation of measurements made by spirometry, lung volumes and gas transfer are described as they relate to underlying pathophysiology with updated classification protocols of common impairments. CONCLUSIONS Interpretation of PFTs must be complemented with clinical expertise and consideration of the inherent biological variability of the test and the uncertainty of the test result to ensure appropriate interpretation of an individual's lung function measurements.
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Affiliation(s)
- Sanja Stanojevic
- Dept of Community Health and Epidemiology, Dalhousie University, Halifax, NS, Canada
| | - David A Kaminsky
- Pulmonary Disease and Critical Care Medicine, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - Martin R Miller
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - Bruce Thompson
- Physiology Service, Dept of Respiratory Medicine, The Alfred Hospital and School of Health Sciences, Swinburne University of Technology, Melbourne, Australia
| | - Andrea Aliverti
- Dept of Electronics, Information and Bioengineering (DEIB), Politecnico di Milano, Milan, Italy
| | - Igor Barjaktarevic
- Division of Pulmonary and Critical Care Medicine, University of California, Los Angeles, CA, USA
| | - Brendan G Cooper
- Lung Function and Sleep, Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Bruce Culver
- Dept of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Washington, Seattle, WA, USA
| | - Eric Derom
- Dept of Respiratory Medicine, Ghent University, Ghent, Belgium
| | - Graham L Hall
- Children's Lung Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute and School of Allied Health, Faculty of Health Science, Curtin University, Bentley, Australia
| | - Teal S Hallstrand
- Dept of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Washington, Seattle, WA, USA
| | - Joerg D Leuppi
- University Clinic of Medicine, Cantonal Hospital Basel, Liestal, Switzerland
- University Clinic of Medicine, University of Basel, Basel, Switzerland
| | - Neil MacIntyre
- Division of Pulmonary, Allergy, and Critical Care Medicine, Dept of Medicine, Duke University Medical Center, Durham, NC, USA
| | - Meredith McCormack
- Pulmonary Function Laboratory, Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
| | | | - Erik R Swenson
- Dept of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Washington, Seattle, WA, USA
- VA Puget Sound Health Care System, Seattle, WA, USA
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Chuang ML, Tsai CF, Ueng KC, Weng JH, Tsai MF, Lo CH, Chen GB, Sia SK, Chuang YT, Wu TC, Kao PF, Hsieh MJ. The Impact of Oxygen Pulse and Its Curve Patterns on Male Patients with Heart Failure, Chronic Obstructive Pulmonary Disease, and Healthy Controls—Ejection Fractions, Related Factors and Outcomes. J Pers Med 2022; 12:jpm12050703. [PMID: 35629127 PMCID: PMC9146512 DOI: 10.3390/jpm12050703] [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: 04/01/2022] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 12/04/2022] Open
Abstract
Oxygen pulse (O2P) is a function of stroke volume and cellular oxygen extraction and O2P curve pattern (O2PCP) can provide continuous measurements of O2P. However, measurements of these two components are difficult during incremental maximum exercise. As cardiac function is evaluated using ejection fraction (EF) according to the guidelines and EF can be obtained using first-pass radionuclide ventriculography, the aim of this study was to investigate associations of O2P%predicted and O2PCP with EF in patients with heart failure with reduced or mildly reduced ejection fraction (HFrEF/HFmrEF) and chronic obstructive pulmonary disease (COPD), and also in normal controls. This was a prospective observational cross-sectional study. Correlations of resting left ventricular EF, dynamic right and left ventricular EFs and outcomes with O2P% and O2PCP across the three participant groups were analyzed. A total of 237 male subjects were screened and 90 were enrolled (27 with HFrEF/HFmrEF, 30 with COPD and 33 normal controls). O2P% and the proportions of the three types of O2PCP were similar across the three groups. O2P% reflected dynamic right and left ventricular EFs in the control and HFrEF/HFmrEF groups, but did not reflect resting left ventricular EF in all participants. O2PCP did not reflect resting or dynamic ventricular EFs in any of the subjects. A decrease in O2PCP was significantly related to nonfatal cardiac events in the HFrEF/HFmrEF group (log rank test, p = 0.01), whereas O2P% and O2PCP did not predict severe acute exacerbations of COPD. The findings of this study may clarify the utility of O2P and O2PCP, and may contribute to the currently used interpretation algorithm and the strategy for managing patients, especially those with HFrEF/HFmrEF. (Trial registration number NCT05189301.)
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Affiliation(s)
- Ming-Lung Chuang
- Division of Pulmonary Medicine and Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung 40201, Taiwan; (G.-B.C.); (T.-C.W.)
- School of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan; (C.-F.T.); (K.-C.U.); (J.-H.W.); (S.-K.S.); (Y.-T.C.); (P.-F.K.)
- Correspondence: (M.-L.C.); (M.-J.H.)
| | - Chin-Feng Tsai
- School of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan; (C.-F.T.); (K.-C.U.); (J.-H.W.); (S.-K.S.); (Y.-T.C.); (P.-F.K.)
- Division of Cardiology, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung 40201, Taiwan;
| | - Kwo-Chang Ueng
- School of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan; (C.-F.T.); (K.-C.U.); (J.-H.W.); (S.-K.S.); (Y.-T.C.); (P.-F.K.)
- Division of Cardiology, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung 40201, Taiwan;
| | - Jui-Hung Weng
- School of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan; (C.-F.T.); (K.-C.U.); (J.-H.W.); (S.-K.S.); (Y.-T.C.); (P.-F.K.)
- Department of Nuclear Medicine, Chung Shan Medical University Hospital, Taichung 40201, Taiwan
| | - Ming-Fong Tsai
- Department of Nuclear Medicine, Chiayi Chang Gung Memorial Hospital, Chang Gung Medical Foundation, Chiayi 61301, Taiwan;
| | - Chien-Hsien Lo
- Division of Cardiology, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung 40201, Taiwan;
- Institute of Medicine, School of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan
| | - Gang-Bin Chen
- Division of Pulmonary Medicine and Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung 40201, Taiwan; (G.-B.C.); (T.-C.W.)
| | - Sung-Kien Sia
- School of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan; (C.-F.T.); (K.-C.U.); (J.-H.W.); (S.-K.S.); (Y.-T.C.); (P.-F.K.)
- Division of Cardiology, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung 40201, Taiwan;
| | - Yao-Tsung Chuang
- School of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan; (C.-F.T.); (K.-C.U.); (J.-H.W.); (S.-K.S.); (Y.-T.C.); (P.-F.K.)
- Division of Cardiology, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung 40201, Taiwan;
| | - Tzu-Chin Wu
- Division of Pulmonary Medicine and Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung 40201, Taiwan; (G.-B.C.); (T.-C.W.)
| | - Pan-Fu Kao
- School of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan; (C.-F.T.); (K.-C.U.); (J.-H.W.); (S.-K.S.); (Y.-T.C.); (P.-F.K.)
- Department of Nuclear Medicine, Chung Shan Medical University Hospital, Taichung 40201, Taiwan
| | - Meng-Jer Hsieh
- Department of Respiratory Therapy, Chang Gung University, Taoyuan 33303, Taiwan
- Department of Pulmonary and Critical Care Medicine, Chiayi Chang Gung Memorial Hospital, Chang Gung Medical Foundation, Chiayi 61301, Taiwan
- Correspondence: (M.-L.C.); (M.-J.H.)
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12
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Chuang ML, Hsieh BYT, Lin IF. Prediction and types of dead-space fraction during exercise in male chronic obstructive pulmonary disease patients. Medicine (Baltimore) 2022; 101:e28800. [PMID: 35147114 PMCID: PMC8830857 DOI: 10.1097/md.0000000000028800] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 01/19/2022] [Indexed: 11/30/2022] Open
Abstract
A high dead space (VD) to tidal volume (VT) ratio during peak exercise (VD/VTpeak) is a sensitive and consistent marker of gas exchange abnormalities; therefore, it is important in patients with chronic obstructive pulmonary disease (COPD). However, it is necessary to use invasive methods to obtain VD/VTpeak, as noninvasive methods, such as end-tidal PCO2 (PETCO2peak) and PETCO2 adjusted with Jones' equation (PJCO2peak) at peak exercise, have been reported to be inconsistent with arterial PCO2 at peak exercise (PaCO2peak). Hence, this study aimed to generate prediction equations for VD/VTpeak using statistical techniques, and to use PETCO2peak and PJCO2peak to calculate the corresponding VD/VTpeaks (i.e., VD/VTpeakETVD/VTpeakJ).A total of 46 male subjects diagnosed with COPD who underwent incremental cardiopulmonary exercise tests with PaCO2 measured via arterial catheterization were enrolled. Demographic data, blood laboratory tests, functional daily activities, chest radiography, two-dimensional echocardiography, and lung function tests were assessed.In multivariate analysis, diffusing capacity, vital capacity, mean inspiratory tidal flow, heart rate, and oxygen pulse at peak exercise were selected with a predictive power of 0.74. There were no significant differences in the PCO2peak values and the corresponding VD/VTpeak values across the three types (both p = NS).In subjects with COPD, VD/VTpeak can be estimated using statistical methods and the PETCO2peak and PJCO2peak. These methods may have similar predictive power and thus can be used in clinical practice.
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Affiliation(s)
- Ming-Lung Chuang
- Division of Pulmonary Medicine and Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan, ROC
- School of Medicine, Chung Shan Medical University, Taichung, Taiwan, ROC
| | | | - I-Feng Lin
- Institute of Public Health, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC
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López-Campos JL, Carrasco Hernández L, Ruiz-Duque B, Reinoso-Arija R, Caballero-Eraso C. Step-Up and Step-Down Treatment Approaches for COPD: A Holistic View of Progressive Therapies. Int J Chron Obstruct Pulmon Dis 2021; 16:2065-2076. [PMID: 34285480 PMCID: PMC8285922 DOI: 10.2147/copd.s275943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 06/19/2021] [Indexed: 11/30/2022] Open
Abstract
Recent advances in inhaled drugs and a clearer definition of the disease have made the task of managing COPD more complex. Different proposals have been put forward which combine all the available treatments and the different clinical presentations in an effort to select the best therapeutic options for each clinical context. As COPD is a chronic progressive disease, the escalation of therapy has traditionally been considered the most natural way to tackle it. However, the notion of COPD as a constantly progressing disease has recently been challenged and, in specific areas, this points to the possibility of a de-escalation in treatment. In this context, the clinician requires simple, specific recommendations to guide these changes in treatment in their daily clinical practice. To accomplish this, the first step must be a correct evaluation and an accurate initial preliminary diagnosis of the patient's condition. Thereafter, the first escalation in therapy must be introduced with caution as the disease progresses, since clinical trials are not designed with clinical decision-making in mind. During this escalation, three possibilities are open to change the current treatment for a different one within the same family, to increase non-pharmacological interventions or to increase the pharmacological therapies. Beyond that point, a patient with persistent symptoms represents a complex clinical scenario which requires a specialized approach, including the evaluation of different respiratory and non-respiratory comorbidities. Unfortunately, there are few de-escalation studies available, and these are mainly observational in nature. The debate on de-escalation in pharmacological treatment, therefore, involves two main discussion points: the withdrawal of bronchodilators and the withdrawal of inhaled steroids. Altogether, the scheme for modifying treatment must be more personalized than just adding molecules, and the therapeutic response and its conditioning factors should be evaluated at each step before proceeding further.
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Affiliation(s)
- Jose Luis López-Campos
- Unidad Médico-Quirúrgica de Enfermedades Respiratorias, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/Universidad de Sevilla, Seville, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
| | - Laura Carrasco Hernández
- Unidad Médico-Quirúrgica de Enfermedades Respiratorias, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/Universidad de Sevilla, Seville, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
| | - Borja Ruiz-Duque
- Unidad Médico-Quirúrgica de Enfermedades Respiratorias, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/Universidad de Sevilla, Seville, Spain
| | - Rocio Reinoso-Arija
- Unidad Médico-Quirúrgica de Enfermedades Respiratorias, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/Universidad de Sevilla, Seville, Spain
| | - Candelaria Caballero-Eraso
- Unidad Médico-Quirúrgica de Enfermedades Respiratorias, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/Universidad de Sevilla, Seville, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
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Miller MR, Cooper BG. Reduction in TLco and survival in a clinical population. Eur Respir J 2021; 58:13993003.02046-2020. [PMID: 33863741 DOI: 10.1183/13993003.02046-2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 03/29/2021] [Indexed: 11/05/2022]
Abstract
How best to express the level of lung gas transfer (TLco) function has not been properly explored. We used the most recent clinical data from 13 829 patients (54% male, 10% non-European ancestry), median age 60.5 years (range 20-97), median survival 3.5 years (range 0-20) to determine how best to express TLco function in terms of its relation to survival. The proportion of subjects of non-European ancestry with Global Lung Function Initiative (GLI) TLco z-scores above predicted was reduced but was significantly increased between -1.5 to -3.5 suggesting the need for ethnicity appropriate equations. Applying GLI FVC ethnicity methodology to GLI TLco z-scores removed this ethnic bias and was used for all subsequent analysis. TLco z-scores using the GLI equations were compared with Miller's US equations with median TLco z-scores being -1.43 and -1.50 for GLI and Miller equations respectively (interquartile range -2.8 to -0.3 and -2.4 to -0.7, respectively). GLI TLco z-scores gave the best Cox regression model for predicting survival. A previously proposed six-tier grading system for level of lung function did not show much separation in survival risk in the less severe grades. A new four-tier grading based on z-scores of -1.645, -3 and -5 showed better separation of risk with hazard ratio for all-cause mortality of 2.0, 3.4 and 6.6 with increasing severity. Using GLI FVC ethnicity methodology to GLI TLco predictions removed ethnic bias and may be the best approach until relevant datasets are available.
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Affiliation(s)
| | - Brendan G Cooper
- Lung Function & Sleep, Queen Elizabeth Hospital, University Hospital Birmingham NHS Foundation Trust, Birmingham, UK
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Bhatta L, Leivseth L, Mai XM, Henriksen AH, Carslake D, Chen Y, Martinez-Camblor P, Langhammer A, Brumpton BM. Spirometric Classifications of Chronic Obstructive Pulmonary Disease Severity as Predictive Markers for Clinical Outcomes: The HUNT Study. Am J Respir Crit Care Med 2021; 203:1033-1037. [PMID: 33332249 PMCID: PMC8048755 DOI: 10.1164/rccm.202011-4174le] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Laxmi Bhatta
- Norwegian University of Science and TechnologyTrondheim, Norway
| | | | - Xiao-Mei Mai
- Norwegian University of Science and TechnologyTrondheim, Norway
| | - Anne Hildur Henriksen
- Norwegian University of Science and TechnologyTrondheim, Norway
- Trondheim University HospitalTrondheim, Norway
| | - David Carslake
- MRC Integrative Epidemiology Unit at the University of BristolBristol, United Kingdom
| | - Yue Chen
- University of OttawaOttawa, Ontario, Canada
| | | | - Arnulf Langhammer
- Norwegian University of Science and Technology, Levanger, Norwayand
- Nord-Trøndelag Hospital Trust, Levanger, Norway
| | - Ben Michael Brumpton
- Norwegian University of Science and TechnologyTrondheim, Norway
- Trondheim University HospitalTrondheim, Norway
- MRC Integrative Epidemiology Unit at the University of BristolBristol, United Kingdom
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16
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Chuang ML, Hsieh BYT, Lin IF. Resting Dead Space Fraction as Related to Clinical Characteristics, Lung Function, and Gas Exchange in Male Patients with Chronic Obstructive Pulmonary Disease. Int J Gen Med 2021; 14:169-177. [PMID: 33568934 PMCID: PMC7868954 DOI: 10.2147/ijgm.s291555] [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: 11/11/2020] [Accepted: 12/30/2020] [Indexed: 12/16/2022] Open
Abstract
Background Measures of forced expired volume in one second % predicted (FEV1%), residual volume to total lung capacity ratio (RV/TLC) and diffusing capacity for carbon monoxide measurements (DLCO) are the standard lung function test for evaluating patients with chronic obstructive pulmonary disease (COPD). The dead space fraction (VD/VT) has been shown to be a robust marker of gas exchange abnormality. However, the use of VD/VT has gradually become less common. As VD/VT measured at rest (VD/VTR) has been successfully used in non-COPD conditions, it was hypothesized that in COPD the VD/VTR was more sensitive than the standard lung function test in correlation with clinical characteristics and gas exchange. This study aimed to test the hypothesis and to identify the variables relevant to VD/VTR. Methods A total of 46 male subjects with COPD were enrolled. Clinical characteristics included demographic data, oxygen-cost diagram (OCD), and image studies for pulmonary hypertension. The standard lung function was obtained. To calculate VD/VT, invasive arterial blood gas and pulmonary gas exchange (PGX) were measured. The variables relevant to VD/VTR were analyzed by multiple linear regression. Results Compared to lung function, VD/VTR was more frequently and significantly related to smoking, carboxyhemoglobin level, pulmonary hypertension and PaCO2 (all p <0.05) whereas FEV1% was more related to lung function test, PaO2 and OCD score. VD/VTR and FEV1% were highly related to resting gas exchange but RV/TLC and DLCO% were not. Cigarette consumption, the equivalent for CO2 output, arterial oxyhemoglobin saturation, and the product of tidal volume and inspiratory duty cycle were identified as the parameters relevant to VD/VTR with a power of 0.72. Conclusion Compared to lung function test, VD/VTR is more related to clinical characteristics and is a comprehensive marker of resting gas exchange. Further studies are warranted to provide a noninvasive measurement of VD/VTR. Registration Number MOST 106-2314-B-040-025 and CSH-2019-C-30.
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Affiliation(s)
- Ming-Lung Chuang
- Division of Pulmonary Medicine and Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan, 40201, Republic of China.,School of Medicine, Chung Shan Medical University, Taichung, Taiwan, 40201, Republic of China
| | | | - I-Feng Lin
- Institute of Public Health, National Yang Ming University, Taipei, Taiwan, 11221, Republic of China
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Chuang ML. Mechanisms affecting exercise ventilatory inefficiency-airflow obstruction relationship in male patients with chronic obstructive pulmonary disease. Respir Res 2020; 21:206. [PMID: 32762752 PMCID: PMC7409645 DOI: 10.1186/s12931-020-01463-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 07/22/2020] [Indexed: 12/12/2022] Open
Abstract
Background Exercise ventilatory inefficiency is usually defined as high ventilation (\documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}}\mathrm{CO}2 $$\end{document}V˙CO2). The inefficiency may be lowered when airflow obstruction is severe because \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}}\mathrm{E} $$\end{document}V˙E cannot be adequately increased in response to exercise. However, the ventilatory inefficiency-airflow obstruction relationship differs to a varying degree. This has been hypothesized to be affected by increased dead space fraction of tidal volume (VD/VT), acidity, hypoxemia, and hypercapnia. Methods A total of 120 male patients with chronic obstructive pulmonary disease were enrolled. Lung function and incremental exercise tests were conducted, and \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}}\mathrm{E}/\dot{\mathrm{V}}\mathrm{CO}2\mathrm{S} $$\end{document}V˙E/V˙CO2S) and intercept (\documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}}\mathrm{E}/\dot{\mathrm{V}}\mathrm{CO}2\mathrm{I} $$\end{document}V˙E/V˙CO2I) were obtained by linear regression. Arterial blood gas analysis was also performed in 47 of the participants during exercise tests. VD/VT and lactate level were measured. Results VD/VTpeak was moderately positively related to \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}}\mathrm{E}/\dot{\mathrm{V}}\mathrm{CO}2\mathrm{S} $$\end{document}V˙E/V˙CO2S (r = 0.41) and negatively related to forced expired volume in 1 sec % predicted (FEV1%) (r = − 0.27), and hence the FEV1%- \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}}\mathrm{E}/\dot{\mathrm{V}}\mathrm{CO}2\mathrm{S} $$\end{document}V˙E/V˙CO2S relationship was paradoxical. The higher the \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}}\mathrm{E}/\dot{\mathrm{V}}\mathrm{CO}2\mathrm{S} $$\end{document}V˙E/V˙CO2S, the higher the pH and PaO2, and the lower the PaCO2 and exercise capacity. \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}}\mathrm{E}/\dot{\mathrm{V}}\mathrm{CO}2\mathrm{I} $$\end{document}V˙E/V˙CO2I was marginally related to VD/VTrest. The higher the \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}}\mathrm{E}/\dot{\mathrm{V}}\mathrm{CO}2\mathrm{I} $$\end{document}V˙E/V˙CO2I, the higher the inspiratory airflow, work rate, and end-tidal PCO2peak. Conclusion 1) Dead space ventilation perturbs the airflow- \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}}\mathrm{E}/\dot{\mathrm{V}}\mathrm{CO}2\mathrm{S} $$\end{document}V˙E/V˙CO2S relationship, 2) increasing ventilation thereby increases \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}}\mathrm{E}/\dot{\mathrm{V}}\mathrm{CO}2\mathrm{S} $$\end{document}V˙E/V˙CO2S to maintain biological homeostasis, and 3) the physiology- \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}}\mathrm{E}/\dot{\mathrm{V}}\mathrm{CO}2\mathrm{I} $$\end{document}V˙E/V˙CO2I relationships are inconsistent in the current and previous studies. Trial Registration MOST 106–2314-B-040-025.
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Affiliation(s)
- Ming-Lung Chuang
- Department of Internal Medicine and Division of Pulmonary Medicine, Chung Shan Medical University Hospital, #110, Section 1, Chien-Kuo North Road, South District, Taichung, 40201, Taiwan, Republic of China. .,School of Medicine, Chung Shan Medical University, Taichung, 40201, Taiwan, Republic of China.
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Anane I, Guezguez F, Knaz H, Ben Saad H. How to Stage Airflow Limitation in Stable Chronic Obstructive Pulmonary Disease Male Patients? Am J Mens Health 2020; 14:1557988320922630. [PMID: 32475199 PMCID: PMC7263160 DOI: 10.1177/1557988320922630] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
No study has evaluated the utility of different classifications of chronic obstructive pulmonary disease (COPD) airflow limitation (AFL) in terms of the refined “ABCD” classification of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) or in terms of the impacts on quality of life. This study aimed to compare some relevant health outcomes (i.e., GOLD classification and quality-of-life scores) between COPD patients having “light” and “severe” AFL according to five COPD AFL classifications. It was a cross-sectional prospective study including 55 stable COPD male patients. The COPD assessment test (CAT), the VQ11 quality-of-life questionnaire, a spirometry, and a bronchodilator test were performed. The patients were divided into GOLD “A/B” and “C/D.” The following five classifications of AFL severity, based on different post-bronchodilator forced expiratory volume in 1 s (FEV1) expressions, were applied: FEV1%pred: “light” (≥50), “severe” (<50); FEV1z-score: “light” (≥−3), “severe” (<−3); FEV1/height2: “light” (≥0.40), “severe” (<0.40); FEV1/height3: “light” (≥0.29), “severe” (<0.29); and FEV1Quotient: “light” (≥2.50), “severe” (<2.50). The percentages of the patients with “severe” AFL were significantly influenced by the applied classification of the AFL severity (89.1 [FEV1z-score], 63.6 [FEV1%pred], 41.8 [FEV1/height3], 40.0 [FEV1Quotient], and 25.4 [FEV1/height2]; Cochrane test = 91.49, df = 4). The CAT and VQ11 scores were significantly different between the patients having “light” and “severe” AFL. In GOLD “C/D” patients, only the FEV1Quotient was able to distinguish between the two AFL severities. To conclude, the five classifications of COPD AFL were not similar when compared with regard to some relevant health outcomes.
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Affiliation(s)
- Ichraf Anane
- Laboratory of Physiology and Functional Explorations, Farhat HACHED Hospital, Sousse, Tunisia.,Heart Failure (LR12SP09) Research Laboratory, Farhat HACHED Hospital, Sousse, Tunisia
| | - Fatma Guezguez
- Laboratory of Physiology and Functional Explorations, Farhat HACHED Hospital, Sousse, Tunisia.,Heart Failure (LR12SP09) Research Laboratory, Farhat HACHED Hospital, Sousse, Tunisia
| | - Hend Knaz
- Laboratory of Physiology and Functional Explorations, Farhat HACHED Hospital, Sousse, Tunisia
| | - Helmi Ben Saad
- Laboratory of Physiology and Functional Explorations, Farhat HACHED Hospital, Sousse, Tunisia.,Laboratory of Physiology, Faculty of Medicine of Sousse, University of Sousse, Tunisia
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Abstract
RATIONALE Current guidelines recommend using forced expiratory volume in 1 second (FEV1) % predicted to categorize the severity of airflow obstruction. There are limitations to using FEV1 % predicted for this purpose, including bias associated with demographic factors and the inability to correct for "lung size." Other methods for grading the severity of airflow obstruction have been proposed to address these limitations. OBJECTIVES Our objectives were to categorize airflow obstruction severity using these methods and then determine which method results in a categorization most closely associated with mortality. METHODS Study subjects were patients aged 40-80 years tested in our pulmonary function test laboratories in the period 2002 to 2013 with airflow obstruction based on an FEV1/forced vital capacity (FVC) less than the lower limit of normal. Categorization of airflow obstruction severity was determined using four methods: FEV1 % predicted; FEV1 % predicted adjusted by FVC % predicted; FEV1/FVC confidence interval approach; and FEV1 z-scores. Receiver operating characteristic curve analysis was used to determine which categorization method best predicts 5-year survival. RESULTS We identified 2,000 patients with airflow obstruction. Important differences in the categorization of airflow obstruction severity were observed using the different methods. More patients were categorized as having severe obstruction using FEV1 % predicted and FEV1 z-scores compared with FEV1 % predicted adjusted by FVC % predicted and FEV1/FVC confidence interval approach. FEV1 % predicted was the best predictor of 5-year survival among the four methods studied. CONCLUSIONS In our study, categorizing airflow obstruction severity using FEV1 % predicted best predicted 5-year survival. This validates the current guideline recommendation that FEV1 % predicted be used to categorize the severity of airflow obstruction.
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Chuang ML, Lin IF. Investigating the relationships among lung function variables in chronic obstructive pulmonary disease in men. PeerJ 2019; 7:e7829. [PMID: 31592356 PMCID: PMC6777488 DOI: 10.7717/peerj.7829] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 09/04/2019] [Indexed: 02/02/2023] Open
Abstract
Background In patients with chronic obstructive pulmonary disease (COPD), the independent contributions of individual lung function variables to outcomes may be lower when they are modelled together if they are collinear. In addition, lung volume measurements may not be necessary after spirometry data have been obtained. However, these hypotheses depend on whether forced vital capacity (FVC) can predict total lung capacity (TLC). Moreover, the definitions of hyperinflation and air trapping according to lung function variables overlap and need be clarified. Therefore, the aim of this study was to evaluate the relationships among various lung function parameters to elucidate these issues. Methods Demographic data and 26 parameters of full lung function were measured in 94 men with COPD and analyzed using factor and correlation analyses. Results Factor analysis revealed five latent factors. Inspiratory capacity (IC)/TLC and residual volume (RV)/TLC were most strongly correlated with all other lung volumes. IC/TLC, RV/TLC, and functional residual capacity (FRC)/TLC were collinear and were potential markers of air trapping, whereas TLC%, FRC%, and RV% were collinear and were potential markers of hyperinflation. RV/TLC >0.4 (or IC/TLC <0.4) was comparable with the ratio of forced expiratory volume in one second (FEV1) and FVC <0.7. FVC% and FEV1% were poorly correlated with TLC%. The correlation study showed that TLC%, RV/TLC, and FEV1% could be used to represent individual latent factors for hyperinflation, air trapping, inspiration, expiration, and obstruction. Combined with diffusion capacity%, these four factors could be used to represent comprehensive lung function. Conclusions This study identified collinear relationships among individual lung function variables and thus selecting variables with close relationships for correlation studies should be performed with caution. This study also differentiated variables for air trapping and lung hyperinflation. Lung volume measurements are still required even when spirometry data are available. Four out of 26 lung function variables from individual latent factors could be used to concisely represent lung function.
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Affiliation(s)
- Ming-Lung Chuang
- Division of Pulmonary Medicine, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan.,School of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - I-Feng Lin
- Institute of Public Health, National Yang Ming University, Taipei, Taiwan
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Culver BH. Assessment of severity and prognosis in COPD: moving beyond percent of predicted. Eur Respir J 2018; 52:52/2/1801005. [PMID: 30072543 DOI: 10.1183/13993003.01005-2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 06/13/2018] [Indexed: 11/05/2022]
Affiliation(s)
- Bruce H Culver
- Division of Pulmonary, Critical Care and Sleep Medicine, Dept of Medicine, University of Washington, Seattle, WA, USA
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