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Kostorz-Nosal S, Jastrzębski D, Błach A, Skoczyński S. Window of opportunity for respiratory oscillometry: A review of recent research. Respir Physiol Neurobiol 2023; 316:104135. [PMID: 37536553 DOI: 10.1016/j.resp.2023.104135] [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: 05/31/2023] [Revised: 07/19/2023] [Accepted: 07/30/2023] [Indexed: 08/05/2023]
Abstract
Oscillometry has been around for almost 70 years, but there are still many unknowns. The test is performed during tidal breathing and is therefore free from patient-dependent factors that could influence the results. The Forced Oscillation Technique (FOT), which requires minimal patient cooperation, is gaining ground, particularly with elderly patients and children. In pulmonology, it is a valuable tool for assessing obstructive conditions (with a distinction between central and peripheral obstruction) and restrictive disorders (intrapulmonary and extrapulmonary). Its sensitivity allows the assessment of bronchodilator and bronchoconstrictor responses. Different lung diseases show different patterns of changes in FOT, especially studied in asthma and chronic obstructive pulmonary disease. Because of these differences, many studies have analysed the usefulness of this technique in different areas of medicine. In this paper, the authors would like to present the basics of oscillometry with the areas of its most recent clinical applications.
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Affiliation(s)
- Sabina Kostorz-Nosal
- Department of Lung Diseases and Tuberculosis, Faculty of Medical Sciences in Zabrze, Medical University of Silesia in Katowice, 41-803 Zabrze, Poland.
| | - Dariusz Jastrzębski
- Department of Lung Diseases and Tuberculosis, Faculty of Medical Sciences in Zabrze, Medical University of Silesia in Katowice, 41-803 Zabrze, Poland
| | - Anna Błach
- Department of Cardiology and Structural Heart Diseases, Medical University of Silesia, Katowice, Poland
| | - Szymon Skoczyński
- Department of Lung Diseases and Tuberculosis, Faculty of Medical Sciences in Zabrze, Medical University of Silesia in Katowice, 41-803 Zabrze, Poland
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Petersson Sjögren M, Kåredal M, Broberg K, Assarsson E, Thuresson S, Dierschke K, Hedmer M, Rissler J, Wollmer P, Löndahl J. Sensitive methods for assessment of lung health in welders and controls. Respir Med 2023; 212:107244. [PMID: 37062499 DOI: 10.1016/j.rmed.2023.107244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 04/04/2023] [Accepted: 04/05/2023] [Indexed: 04/18/2023]
Abstract
BACKGROUND Welders are exposed to gas and particle emissions that can cause severe lung disease, such as chronic obstructive pulmonary disease (COPD), a leading cause of mortality and morbidity worldwide. It is hard to detect COPD early and therefore mitigating measures may be delayed. The aim of this study was to investigate lung health in welders and evaluate new sensitive methods with potential to assess early onset pulmonary changes in occupational settings. METHODS This study assessed the lung health and symptoms in active welders (n = 28) and controls (n = 17). Lung measurements were performed with standard spirometry and new methods: airspace dimension assessment (AiDA), oscillometry, blood serum biomarkers (club cell secretory protein 16, surfactant protein D, matrix metalloproteinases, fibroblast, hepatocyte growth factor, interleukins), and one urine biomarker (desmosine). RESULTS According to spirometry measurements, all participants had normal lung function. However, prevalence of cough was significantly higher among welders compared with controls and lung changes were found in welders with the novel methods. Welders had significantly higher respiratory system resistance assessed with oscillometry, serum levels of metalloproteinases 9 and hepatocyte growth factor, compared with controls. Airspace dimensions were on average higher among welders compared with controls, but the difference was not significant. The number of welding years correlated with decreased respiratory system reactance and increased serum levels of matrix metalloproteinases 9, interleukin 6, and hepatocyte growth factor. Airspace dimension assessment indices significantly correlated with increasing levels of inflammatory markers and matrix metalloproteinases. CONCLUSIONS This study indicated the potential to use new and more sensitive methods for identification of changes in lungs when standard spirometry failed to do so.
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Affiliation(s)
- Madeleine Petersson Sjögren
- Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Lund, Sweden; NanoLund, Lund, Sweden
| | - Monica Kåredal
- NanoLund, Lund, Sweden; Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden; Department of Occupational and Environmental Medicine, Region Skåne, Lund, Sweden
| | - Karin Broberg
- Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden; Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Eva Assarsson
- Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Sara Thuresson
- Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Lund, Sweden; NanoLund, Lund, Sweden
| | - Katrin Dierschke
- Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden; Department of Occupational and Environmental Medicine, Region Skåne, Lund, Sweden
| | - Maria Hedmer
- NanoLund, Lund, Sweden; Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden; Department of Occupational and Environmental Medicine, Region Skåne, Lund, Sweden
| | - Jenny Rissler
- Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Lund, Sweden; NanoLund, Lund, Sweden; RISE Research Institutes of Sweden, Borås, Sweden
| | - Per Wollmer
- Department of Translational Medicine, Clinical Physiology and Nuclear Medicine, Lund University, Malmö, Sweden
| | - Jakob Löndahl
- Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Lund, Sweden; NanoLund, Lund, Sweden.
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Ahookhosh K, Vanoirbeek J, Vande Velde G. Lung function measurements in preclinical research: What has been done and where is it headed? Front Physiol 2023; 14:1130096. [PMID: 37035677 PMCID: PMC10073442 DOI: 10.3389/fphys.2023.1130096] [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: 12/22/2022] [Accepted: 03/10/2023] [Indexed: 04/11/2023] Open
Abstract
Due to the close interaction of lung morphology and functions, repeatable measurements of pulmonary function during longitudinal studies on lung pathophysiology and treatment efficacy have been a great area of interest for lung researchers. Spirometry, as a simple and quick procedure that depends on the maximal inspiration of the patient, is the most common lung function test in clinics that measures lung volumes against time. Similarly, in the preclinical area, plethysmography techniques offer lung functional parameters related to lung volumes. In the past few decades, many innovative techniques have been introduced for in vivo lung function measurements, while each one of these techniques has their own advantages and disadvantages. Before each experiment, depending on the sensitivity of the required pulmonary functional parameters, it should be decided whether an invasive or non-invasive approach is desired. On one hand, invasive techniques offer sensitive and specific readouts related to lung mechanics in anesthetized and tracheotomized animals at endpoints. On the other hand, non-invasive techniques allow repeatable lung function measurements in conscious, free-breathing animals with readouts related to the lung volumes. The biggest disadvantage of these standard techniques for lung function measurements is considering the lung as a single unit and providing only global readouts. However, recent advances in lung imaging modalities such as x-ray computed tomography and magnetic resonance imaging opened new doors toward obtaining both anatomical and functional information from the same scan session, without the requirement for any extra pulmonary functional measurements, in more regional and non-invasive manners. Consequently, a new field of study called pulmonary functional imaging was born which focuses on introducing new techniques for regional quantification of lung function non-invasively using imaging-based techniques. This narrative review provides first an overview of both invasive and non-invasive conventional methods for lung function measurements, mostly focused on small animals for preclinical research, including discussions about their advantages and disadvantages. Then, we focus on those newly developed, non-invasive, imaging-based techniques that can provide either global or regional lung functional readouts at multiple time-points.
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Affiliation(s)
- Kaveh Ahookhosh
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Jeroen Vanoirbeek
- Centre of Environment and Health, Department of Public Health and Primary Care, KU Leuven, Leuven, Belgium
| | - Greetje Vande Velde
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
- *Correspondence: Greetje Vande Velde,
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An analysis of alternative forced oscillation technique reporting and validation methods for within- and between-sessions in healthy adults. Sci Rep 2022; 12:13119. [PMID: 35907930 PMCID: PMC9338972 DOI: 10.1038/s41598-022-17264-2] [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: 02/03/2022] [Accepted: 07/22/2022] [Indexed: 11/08/2022] Open
Abstract
Forced oscillation technique (FOT) provides unique information on respiratory system mechanical properties complementing pulmonary function testing. However, a lack of evidence guiding acquisition/reporting of parameters has slowed clinical FOT adoption. Current European Respiratory Society (ERS) standards recommend 3-5 trials per session comprising three trials with a coefficient of variation (CoV) ≤ 10% for low-frequency resistance. We present an analysis of different combinations of trial selection methods and session validity thresholding variables (low- and mid-frequency resistance and reactance [R5, R19, X5], low-frequency reactance area [AX] and tidal volume) comparing proportion of subjects achieving valid data across two test sessions (7 ± 3 days apart) and within and between session measurement variabilities. 126 (98%) subjects achieved valid data across both sessions (2666 trials). With R5 or R19 as criteria and selection of any three trials from ≥ 4 attempts, ≥ 75% of subjects achieved validity. Furthermore, with R5 or R19 criteria and selection of any trials from ≥ 5 attempts, CoVs for resistance outcomes were reduced within session while variabilities of FOT outcomes between sessions remained consistent. Within session differences in measurement variabilities were not clinically meaningful. Our analyses support current ERS reporting recommendations for healthy adults. Future work should apply this analytic approach to patient populations.
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Lung Function Tests, Quality of Life and Telemedicine: Three Windows on the Multifaceted World of Asthma in Adolescents. CHILDREN 2022; 9:children9040476. [PMID: 35455520 PMCID: PMC9026868 DOI: 10.3390/children9040476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/15/2022] [Accepted: 03/28/2022] [Indexed: 11/17/2022]
Abstract
Asthma is a heterogeneous disease usually characterized by chronic airway inflammation and recognized as the most prevalent chronic illness among children. Despite this, the knowledge as to how asthma affects adolescents is still scarce. One of the main management problems of asthmatic adolescents is the poor adherence to pharmacological and non-pharmacological treatments. The assessment of respiratory function and the impact on quality of life are still two crucial challenges in the management of asthmatic adolescents. Additionally, the COVID-19 pandemic has prompted physicians to explore complementary management strategies including telemedicine technologies. This review aims to provide an update on the contribution of respiratory functional tests, how asthma affects quality of life of adolescents and, finally, how telemedicine contributes to the management of adolescent asthmatics during the COVID-19 pandemic.
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Makan G, Dandurand RJ, Gingl Z, Hantos Z. Intra-breath changes in respiratory mechanics assessed from multi-frequency oscillometry measurements. Physiol Meas 2022; 43. [PMID: 35263717 DOI: 10.1088/1361-6579/ac5bef] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 03/09/2022] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Recent studies in respiratory system impedance (Zrs) with single-frequency oscillometry have demonstrated the utility of novel intra-breath measures of Zrs in the detection of pathological alterations in respiratory mechanics. In the present work, we addressed the feasibility of extracting intra-breath information from Zrs data sets obtained with conventional oscillometry. APPROACH Multi-frequency recordings obtained in a pulmonology practice were re-analysed to track the 11 Hz component of Zrs during normal breathing and compare the intra-breath measures to that obtained with a single 10 Hz signal in the same subjects. A non-linear model was employed to simulate changes in Zrs in the breathing cycle. The values of resistance (R) and reactance (X) at end expiration and end inspiration and their corresponding differences (R and X) were compared. MAIN RESULTS All intra-breath measures exhibited similar mean values at 10 and 11 Hz in each subject; however, the variabilities were higher at 11 Hz, especially for R and X. The poorer quality of the 11 Hz data was primarily caused by the overlapping of modulation side-lobes of adjacent oscillation frequencies. This cross-talk was enhanced by double breathing frequency components due to flow nonlinearities. SIGNIFICANCE Retrospective intra-breath assessment of large or special data bases of conventional oscillometry can be performed to better characterise respiratory mechanics in different populations and disease groups. The results also have implications in the optimum design of multiple-frequency oscillometry (avoidance of densely spaced frequencies) and the use of filtering procedures that preserve the intra-breath modulation information.
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Affiliation(s)
- Gergely Makan
- Department of Technical Informatics, University of Szeged, Árpád tér 2, Szeged, 6720, HUNGARY
| | - Ronald Jean Dandurand
- Respiratory Medicine, McGill University, 1001 Decarie Blvd, Montreal, Quebec, H3A 0G4, CANADA
| | - Zoltan Gingl
- Department of Technical Informatics, Szegedi Tudomanyegyetem, Árpád tér 2., Szeged, 6720, HUNGARY
| | - Zoltán Hantos
- Anesthesiology and Intensive Therapy, Semmelweis University, 78 Üllői út, Budapest, 1082, HUNGARY
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Kulkarni S, Kurane A, Sakate D. Impulse Oscillometry System for the Diagnosis of Wheezing Episode in Children in Office Practice. J Asthma Allergy 2022; 15:353-362. [PMID: 35320988 PMCID: PMC8935627 DOI: 10.2147/jaa.s344643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 02/21/2022] [Indexed: 11/23/2022] Open
Abstract
Background and Objective Objectively differentiating between wheezing episodes and other respiratory disorders will be helpful in treatment in office practice. The impulse oscillometry system has been useful in assessing airway resistance in children 3–6 years old. As the reference values are different in geographical regions the use of the impulse oscillometry is still limited. Comparison between the percent change in IOS parameters as compared to reference standards and changes in actual IOS parameters was done to diagnose wheezing episodes. Methodology Three to six years old children with a history of fever, cough, cold, and/or breathlessness with noisy breathing and who were not on any regular medications, whose parents gave consent were recruited in the study. The children underwent an impulse oscillometry system examination as per the guidelines. The test was repeated after they were given nebulization by salbutamol (2.5 mg) (before COVID 19 pandemic). Final diagnosis was done by following patients for 7 days. Results About 106 children were recruited in the study. Five children could not perform the IOS test. Eighteen children did not complete the follow-up. Hence, 83 children were analyzed. There were 47 males and 36 female patients. The change in actual values of AX, R5, and X20 showed statistically significant difference in wheezing episode group (p-value<0.001). The percentage change as compared to predicted values of R5 and X20 also showed a statistically significant difference in the wheezing episode group and the others group (p-value<0.001). Conclusion The change in actual values of AX, R5, X20, and resonant frequency may help to differentiate wheezing episode from other respiratory diseases.
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Affiliation(s)
- Suhas Kulkarni
- Department of Pediatrics, D.Y. Patil Medical College, Kolhapur, Maharashtra, India
- Correspondence: Suhas Kulkarni, D.Y. Patil Medical College, Kolhapur, Maharashtra, India, Tel +91 231 2601235, Fax +91 231260138, Email
| | - Anil Kurane
- Department of Pediatrics, D.Y. Patil Medical College, Kolhapur, Maharashtra, India
| | - Deepak Sakate
- Department of Statistics and Applied Mathematics, Central University of Tamil Nadu, Thiruvarur, Tamil Nadu, India
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Bizzotto D, Paganini S, Stucchi L, Palmisano Avallone M, Ramirez EM, Pompilio PP, Ferrucci F, Lavoie JP, Dellaca RL. A portable fan-based device for evaluating lung function in horses by the forced oscillation technique. Physiol Meas 2022; 43. [PMID: 35120344 DOI: 10.1088/1361-6579/ac522e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 02/04/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE The assessment of lung mechanics in horses is nowadays based on invasive methods that may require sedation. The forced oscillation technique (FOT) allows the non-invasive assessment of respiratory mechanics during spontaneous breathing, but current devices are complex, cumbersome, expensive, and difficult to be applied in horses. APPROACH We developed a portable FOT device based on a novel approach in which the pressure waveforms are generated by a servo-controlled ducted fan. This new approach allows the design of devices that are more sturdy, compact, and portable compared to already existing approaches. The prototype includes 1) a small microcontroller-based electronic board for controlling the fan and measuring flow and pressure and 2) an optimized data processing algorithm. MAIN RESULTS This device provides a maximum error of 0.06 cmH2O∙s/L and 0.15 cmH2O∙s/L in measuring respiratory resistance and reactance during in-vitro validation. A pilot study was also performed on three healthy horses and three horses with severe equine asthma (SEA) and it demonstrated good tolerability and feasibility of the new device. Total respiratory system resistance (Rrs) and reactance (Xrs) significantly differed (p<0.05) between groups. At 5Hz, Rrs was 0.66±0.02 cmH2O∙s/L and 0.94±0.07 cmH2O∙s/L in healthy and in SEA, respectively. Xrs 0.38±0.02 cmH2O∙s/L and -0.27±0.05 cmH2O∙s/L. SIGNIFICANCE This novel approach for applying FOT allowed the development of a small, affordable and portable device for the non-invasive evaluation of respiratory mechanics in spontaneously breathing horses, providing a useful new tool for improving veterinary respiratory medicine. Moreover, our results provide supporting evidence of the value of this novel approach for developing portable FOT devices also for applications in humans.
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Affiliation(s)
- Davide Bizzotto
- DEIB, Politecnico di Milano Dipartimento di Elettronica Informazione e Bioingegneria, Via Giuseppe Colombo, 40, Milano, 20133, ITALY
| | - Stefano Paganini
- DEIB, Politecnico di Milano Dipartimento di Elettronica Informazione e Bioingegneria, Via Giuseppe Colombo, 40, Milano, Milano, 20133, ITALY
| | - Luca Stucchi
- Equine Sports Medicine Lab (ESM-Lab), Università degli Studi di Milano Dipartimento di Medicina Veterinaria, Via dell'Università, 6, 26900 Lodi LO, Lodi, Lombardia, 26900, ITALY
| | - Matteo Palmisano Avallone
- DEIB, Politecnico di Milano Dipartimento di Elettronica Informazione e Bioingegneria, Via Giuseppe Colombo, 40, Milano, Milano, 20133, ITALY
| | - Esther Millares Ramirez
- Equine Asthma Laboratory, Université de Montréal Faculté de médecine vétérinaire, 3200 Rue Sicotte, Saint-Hyacinthe, QC J2S 2M2, Canada, Saint Hyacinthe, Quebec, J2S 7C6, CANADA
| | - Pasquale P Pompilio
- Restech srl, Via Melchiorre Gioia, 61, 20124 Milano MI, Milano, 20124, ITALY
| | - Francesco Ferrucci
- Equine Sports Medicine Lab (ESM-Lab), Università degli Studi di Milano Dipartimento di Medicina Veterinaria, Via dell'Università, 6, 26900 Lodi LO, Lodi, Lombardia, 26900, ITALY
| | - Jean-Pierre Lavoie
- Equine Asthma Laboratory, Université de Montréal Faculté de médecine vétérinaire, 3200 Rue Sicotte, Saint-Hyacinthe, QC J2S 2M2, Canada, Saint Hyacinthe, Quebec, J2S 2M2, CANADA
| | - Raffaele L Dellaca
- DEIB, Politecnico di Milano Dipartimento di Elettronica e Informazione, Via Giuseppe Colombo, 40, Milano, Milano, Lombardia, 20133, ITALY
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Kooner HK, McIntosh MJ, Desaigoudar V, Rayment JH, Eddy RL, Driehuys B, Parraga G. Pulmonary functional MRI: Detecting the structure-function pathologies that drive asthma symptoms and quality of life. Respirology 2022; 27:114-133. [PMID: 35008127 PMCID: PMC10025897 DOI: 10.1111/resp.14197] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 11/09/2021] [Accepted: 12/12/2021] [Indexed: 12/21/2022]
Abstract
Pulmonary functional MRI (PfMRI) using inhaled hyperpolarized, radiation-free gases (such as 3 He and 129 Xe) provides a way to directly visualize inhaled gas distribution and ventilation defects (or ventilation heterogeneity) in real time with high spatial (~mm3 ) resolution. Both gases enable quantitative measurement of terminal airway morphology, while 129 Xe uniquely enables imaging the transfer of inhaled gas across the alveolar-capillary tissue barrier to the red blood cells. In patients with asthma, PfMRI abnormalities have been shown to reflect airway smooth muscle dysfunction, airway inflammation and remodelling, luminal occlusions and airway pruning. The method is rapid (8-15 s), cost-effective (~$300/scan) and very well tolerated in patients, even in those who are very young or very ill, because unlike computed tomography (CT), positron emission tomography and single-photon emission CT, there is no ionizing radiation and the examination takes only a few seconds. However, PfMRI is not without limitations, which include the requirement of complex image analysis, specialized equipment and additional training and quality control. We provide an overview of the three main applications of hyperpolarized noble gas MRI in asthma research including: (1) inhaled gas distribution or ventilation imaging, (2) alveolar microstructure and finally (3) gas transfer into the alveolar-capillary tissue space and from the tissue barrier into red blood cells in the pulmonary microvasculature. We highlight the evidence that supports a deeper understanding of the mechanisms of asthma worsening over time and the pathologies responsible for symptoms and disease control. We conclude with a summary of approaches that have the potential for integration into clinical workflows and that may be used to guide personalized treatment planning.
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Affiliation(s)
- Harkiran K Kooner
- Robarts Research Institute, Western University, London, Ontario, Canada
- Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - Marrissa J McIntosh
- Robarts Research Institute, Western University, London, Ontario, Canada
- Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - Vedanth Desaigoudar
- Robarts Research Institute, Western University, London, Ontario, Canada
- Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - Jonathan H Rayment
- Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Rachel L Eddy
- Centre of Heart Lung Innovation, Division of Respiratory Medicine, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Bastiaan Driehuys
- Center for In Vivo Microscopy, Duke University Medical Centre, Durham, North Carolina, USA
| | - Grace Parraga
- Robarts Research Institute, Western University, London, Ontario, Canada
- Department of Medical Biophysics, Western University, London, Ontario, Canada
- Division of Respirology, Department of Medicine, Western University, London, Ontario, Canada
- School of Biomedical Engineering, Western University, London, Ontario, Canada
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Cottini M, Licini A, Lombardi C, Bagnasco D, Comberiati P, Berti A. Small airway dysfunction and poor asthma control: a dangerous liaison. Clin Mol Allergy 2021; 19:7. [PMID: 34051816 PMCID: PMC8164746 DOI: 10.1186/s12948-021-00147-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 05/22/2021] [Indexed: 01/05/2023] Open
Abstract
Asthma is a common chronic condition, affecting approximately 339 million people worldwide. The main goal of the current asthma treatment guidelines is to achieve clinical control, encompassing both the patient symptoms and limitations and the future risk of adverse asthma outcomes. Despite randomized controlled trials showing that asthma control is an achievable target, a substantial proportion of asthmatics remain poorly controlled in real life. The involvement of peripheral small airways has recently gained greater recognition in asthma, and many studies suggest that the persistent inflammation at these sites leads to small airway dysfunction (SAD), strongly contributing to a worse asthma control. Overall, the impulse oscillometry (IOS), introduced in the recent years, seems to be able to sensitively assess small airways, while conventional spirometry does not. Therefore, IOS may be of great help in characterizing SAD and guiding therapy choice. The aim of this article is to review the literature on SAD and its influence on asthma control, emphasizing the most recent evidence.
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Affiliation(s)
| | - Anita Licini
- Allergy and Pneumology Outpatient Clinic, Bergamo, Italy
| | - Carlo Lombardi
- Departmental Unit of Allergology, Immunology and Pulmonary Diseases, Fondazione Poliambulanza, Brescia, Italy
| | - Diego Bagnasco
- Allergy and Respiratory Diseases, IRCCS Policlinico San Martino, University of Genoa, Genova, Italy.
| | - Pasquale Comberiati
- Section of Pediatrics, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Alvise Berti
- Ospedale Santa Chiara and Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy.,Thoracic Disease Research Unit, Mayo Clinic, Rochester, MN, USA
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Dahl MJ, Veneroni C, Lavizzari A, Bowen S, Emerson H, Rebentisch A, Dawson E, Summers K, Pettet L, Wang Z, Null DM, Yoder BA, Dellacà RL, Albertine KH. Early extubation to noninvasive respiratory support of former preterm lambs improves long-term respiratory outcomes. Am J Physiol Lung Cell Mol Physiol 2021; 321:L248-L262. [PMID: 34009031 DOI: 10.1152/ajplung.00051.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Invasive mechanical ventilation (IMV) and exposure to oxygen-rich gas during early postnatal life are contributing factors for long-term pulmonary morbidities faced by survivors of preterm birth and bronchopulmonary dysplasia. The duration of IMV that leads to long-term pulmonary morbidities is unknown. We compared two durations of IMV (3 h vs. 6 days) during the first 6-7 days of postnatal life in preterm lambs to test the hypothesis that minimizing the duration of IMV will improve long-term respiratory system mechanics and structural outcomes later in life. Moderately preterm (∼85% gestation) lambs were supported by IMV for either 3 h or 6 days before weaning from all respiratory support to become former preterm lambs. Respiratory system mechanics and airway reactivity were assessed monthly from 1 to 6 mo of chronological postnatal age by the forced oscillation technique. Quantitative morphological measurements were made for smooth muscle accumulation around terminal bronchioles and indices of alveolar formation. Minimizing IMV to 3 h led to significantly better (P < 0.05) baseline respiratory system mechanics and less reactivity to methacholine in the first 3 mo of chronological age (2 mo corrected age), significantly less (P < 0.05) accumulation of smooth muscle around peripheral resistance airways (terminal bronchioles), and significantly better (P < 0.05) alveolarization at the end of 5 mo corrected age compared with continuous IMV for 6 days. We conclude that limiting the duration of IMV following preterm birth of fetal lambs leads to better respiratory system mechanics and structural outcomes later in life.
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Affiliation(s)
- Mar Janna Dahl
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Chiara Veneroni
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
| | - Anna Lavizzari
- U.O. di Neonatologia e Terapia Intensiva Neonatale, Department of Clinical Sciences and Community Health, University of Milan Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Sydney Bowen
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Haleigh Emerson
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Andrew Rebentisch
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Elaine Dawson
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Kyle Summers
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Luke Pettet
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Zhengming Wang
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Donald M Null
- Division of Neonatology, University of California, Davis, California
| | - Bradley A Yoder
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Raffaele L Dellacà
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
| | - Kurt H Albertine
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
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13
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Lundblad LKA, Robichaud A. Oscillometry of the respiratory system: a translational opportunity not to be missed. Am J Physiol Lung Cell Mol Physiol 2021; 320:L1038-L1056. [PMID: 33822645 PMCID: PMC8203417 DOI: 10.1152/ajplung.00222.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Airway oscillometry has become the de facto standard for quality assessment of lung physiology in laboratory animals and has demonstrated its usefulness in understanding diseases of small airways. Nowadays, it is seeing extensive use in daily clinical practice and research; however, a question that remains unanswered is how well physiological findings in animals and humans correlate? Methodological and device differences are obvious between animal and human studies. However, all devices deliver an oscillated airflow test signal and output respiratory impedance. In addition, despite analysis differences, there are ways to interpret animal and human oscillometry data to allow suitable comparisons. The potential with oscillometry is its ability to reveal universal features of the respiratory system across species, making translational extrapolation likely to be predictive. This means that oscillometry can thus help determine if an animal model displays the same physiological characteristics as the human disease. Perhaps more importantly, it can also be useful to determine whether an intervention is effective as well as to understand if it affects the desired region of the respiratory system, e.g., the periphery of the lung. Finally, findings in humans can also inform preclinical scientists and give indications as to what type of physiological changes should be observed in animal models to make them relevant as models of human disease. The present article will attempt to demonstrate the potential of oscillometry in respiratory research, an area where the development of novel therapies is plagued with a failure rate higher than in other disease areas.
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Affiliation(s)
- Lennart K A Lundblad
- Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada.,THORASYS Thoracic Medical Systems Inc., Montreal, Quebec, Canada
| | - Annette Robichaud
- SCIREQ Scientific Respiratory Equipment Inc., Montreal, Quebec, Canada
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14
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Chaiwong W, Namwongprom S, Liwsrisakun C, Pothirat C. Diagnostic Ability of Impulse Oscillometry in Diagnosis of Chronic Obstructive Pulmonary Disease. COPD 2020; 17:635-646. [PMID: 33121279 DOI: 10.1080/15412555.2020.1839042] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The diagnosis of chronic obstructive pulmonary disease (COPD) mainly relies on spirometry. Due to the complexity of spirometry, easier-to-do impulse oscillometry (IOS) has been introduced as a complementary approach to conventional pulmonary function testing. Therefore, this study aimed to assess the efficacy of the diagnostic ability of IOS for diagnosing chronic obstructive pulmonary disease (COPD). This cross-sectional study was conducted at the Lung Health Center, Chiang Mai University, Thailand, between June 2019 and January 2020. IOS and spirometry were performed with all subjects suspected of having COPD. A Receiver Operating Characteristic (ROC) curve was plotted, the area under the ROC (AuROC) and 95%CI were compared among COPD and chronic smokers. One hundred and seventeen subjects suspected of having COPD with a mean age of 68.6 ± 8.6 years old were enrolled. Of these 103 (88.0%) were male. Thirty healthy subjects were also enrolled. IOS parameters including resistance at 5 Hz (R5), resonant frequency (Fres), area under reactance (AX), heterogeneity of resistance (R5-R20), and reactance at 5 Hz (X5) demonstrated excellent overall accuracy relative to the diagnosis of COPD with an AuROC ranging from 0.80 - 0.84. The AX ≥ 8.66 cmH2O/L represented an AuROC = 0.79, with a sensitivity of 79.1% and a specificity of 78.0% for the diagnosis of COPD. IOS is a valuable tool for use in the diagnosis of COPD. It may be used in subjects who cannot carry out the spirometric procedure.
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Affiliation(s)
- Warawut Chaiwong
- Division of Pulmonary, Critical Care, and Allergy, Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.,Clinical Epidemiology and Clinical Statistic Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Sirianong Namwongprom
- Clinical Epidemiology and Clinical Statistic Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.,Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Chalerm Liwsrisakun
- Division of Pulmonary, Critical Care, and Allergy, Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Chaicharn Pothirat
- Division of Pulmonary, Critical Care, and Allergy, Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
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15
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Hajdarevic B, Herrmann J, Fonseca da Cruz A, Kaczka DW. System identification of proportional solenoid valve dynamics. INTERNATIONAL JOURNAL OF MODELLING IDENTIFICATION AND CONTROL 2020; 34:103-115. [PMID: 33184571 PMCID: PMC7654981 DOI: 10.1504/ijmic.2020.10032851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We present a system identification technique for the characterisation of the linearity and dynamic response of a PSOL valve and its corresponding electronic control unit (ECU) using bandlimited white noise, as well as pseudo random "non-sum non-difference" (NSND) waveforms consisting of mutually prime frequencies to mitigate the effects of nonlinear distortions. The parameters of several transfer function models were simultaneously estimated from the voltage-flow frequency response using a nonlinear gradient descent technique. Candidate transfer function models were assessed using the mean squared residual (MSR) criterion and the corrected Akaike information criterion (AICc). The MSR yielded a transfer function consisting of 10 poles and 9 zeros, while the AICc yielded a simpler transfer function consisting of 5 poles and 3 zeros. Monte Carlo analysis demonstrated fragile stability for the MSR-selected model with respect to varying parameter values within estimated uncertainties, yet a robust stability for the AICc-selected model.
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Affiliation(s)
- Bakir Hajdarevic
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242 USA
- Department of Anesthesia, University of Iowa, Iowa City, IA 52242 USA
| | - Jacob Herrmann
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242 USA
- Department of Anesthesia, University of Iowa, Iowa City, IA 52242 USA
| | | | - David W. Kaczka
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242 USA
- Department of Anesthesia, University of Iowa, Iowa City, IA 52242 USA
- Department of Radiology, University of Iowa, Iowa City, IA 52242 USA
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16
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New developments in respiratory medicine: a primary immunodeficiency perspective. Curr Opin Allergy Clin Immunol 2020; 20:549-556. [PMID: 32941317 DOI: 10.1097/aci.0000000000000690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW To consider recent developments in respiratory medicine that are of relevance to clinicians caring for adults affected by primary immunodeficiency disorders. RECENT FINDINGS We consider impulse oscillometry, new bronchoscopic techniques for sampling, MRI and PET, the concept of the human airway microbiome, and new treatment approaches for bronchiectasis and interstitial lung disease to better understand the future of respiratory care for people with PID. SUMMARY New approaches to the diagnosis and management of respiratory manifestations of PID have been driven by better understanding of the lung in health and disease, progress in imaging and sampling modalities, and new therapeutics.
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17
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Yasuo M, Kitaguchi Y, Tokoro Y, Kosaka M, Wada Y, Kinjo T, Ushiki A, Yamamoto H, Hanaoka M. Differences Between Central Airway Obstruction and Chronic Obstructive Pulmonary Disease Detected with the Forced Oscillation Technique. Int J Chron Obstruct Pulmon Dis 2020; 15:1425-1434. [PMID: 32606651 PMCID: PMC7310967 DOI: 10.2147/copd.s246126] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 05/24/2020] [Indexed: 12/13/2022] Open
Abstract
Background Obstructive ventilatory disturbances occur in both chronic obstructive pulmonary disease (COPD), a typical disease representative of peripheral airway obstruction, and central airway obstruction (CAO). Pulmonary function tests (PFTs), which depend on patient effort, are traditionally used to evaluate lung function. The forced oscillation technique (FOT) is an effort-independent method for examining lung function during tidal breathing. The FOT is used universally to assess respiratory function in patients with COPD. Several studies have measured FOT to assess ventilatory disturbances in CAO. The results showed that FOT measurements in patients with CAO were similar to those reported in patients with COPD. However, no studies have compared FOT measurements directly between CAO and COPD. The aim of this study was to identify differences in ventilatory disturbances between peripheral and central airway obstructions in COPD and CAO, before patients received pharmacological therapy or bronchoscopic interventions, respectively. Patients and Methods We retrospectively included 16 patients with CAO (10 cases of tracheal obstruction and 6 cases of bronchial obstruction) and 75 treatment-naïve patients with COPD (60 cases in Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage II and 15 cases in GOLD stage III) that were admitted from December 2013 to May 2017. Prior to treatment, patients were examined with the FOT and PFTs. Results All parameters measured with the FOT in the inspiratory phase were significantly worse in patients with CAO than in patients with COPD. The PFTs showed that the CAO group had a significantly lower peak expiratory flow rate. In the airway wall thickening phenotype of COPD, a difference between the inspiratory and expiratory phases of the resonance frequency (ΔFres) was the best indicator for distinguishing between peripheral and central airway obstructions. Conclusion This study compared differences between CAO and COPD (mainly GOLD stage II). We found that the FOT measurement, ΔFres, was the optimal indicator of the difference between the airway wall thickening COPD phenotype and CAO. Thus, the difference might be due to mechanical changes that occur in COPD with airway wall thickening.
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Affiliation(s)
- Masanori Yasuo
- The First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan
| | - Yoshiaki Kitaguchi
- The First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan
| | - Yayoi Tokoro
- The First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan
| | - Makoto Kosaka
- The First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan
| | - Yosuke Wada
- The First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan
| | - Takumi Kinjo
- The First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan
| | - Atsuhito Ushiki
- The First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan
| | - Hiroshi Yamamoto
- The First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan
| | - Masayuki Hanaoka
- The First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan
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18
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Zannin E, Aarli BB, Govoni L, Pompilio PP, Baldi S, Hardie JA, Dellacà RL. Effect of stimulating waveform and of data processing on respiratory impedance measurement. Physiol Meas 2020; 41:055005. [DOI: 10.1088/1361-6579/ab87b1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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19
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Bednarek M, Grabicki M, Piorunek T, Batura-Gabryel H. "Current place of impulse oscillometry in the assessment of pulmonary diseases.". Respir Med 2020; 170:105952. [PMID: 32843158 DOI: 10.1016/j.rmed.2020.105952] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 12/01/2022]
Abstract
In 1956, a diagnostic tool using the forced oscillation technique (FOT) was developed to examine respiratory functions. A modification of this method is impulse oscillometry (IOS). In the latter, a loudspeaker delivers to the respiratory system a regular, square pressure wave at a constant frequency from which all other individual frequencies are derived using spectral analysis. The usefulness of IOS has been examined in relation to COPD, asthma, interstitial lung diseases, obstructive sleep apnea, and other conditions. The greatest advantage, most notable in children, is the ability to monitor the course of a disease and to assess the response to therapy in a simple way, i.e., minimal requirements for the cooperation of the patient, rapid and reproducible measurements. The IOS shows similar or even higher sensitivity than spirometry in detecting small airways dysfunction (SAD). The most well-known result observed in peripheral airways disease (PAD) is the frequency dependence of resistance. Importantly, the abnormal resistance at a specific frequency may occur with normal spirometry in those with early PAD. Moreover, IOS is particularly useful if the patient cannot perform effort dependent exhalation. Despite its advantages, the technique is still poorly found in official worldwide recommendations. Nonetheless, considering the promising results of many studies, an increase in interest in IOS is expected, and it could soon be on par with standard pulmonary function tests. The aim of this work is to present the basics, current views, and various aspects of IOS. To carry out our analysis, we searched for relevant publications on PubMed, Web of Science. Original and review articles were selected and discussed.
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Affiliation(s)
- Marcin Bednarek
- Poznan University of Medical Sciences, Department of Pulmonology, Allergology and Respiratory Oncology, ul. Szamarzewskiego 84, 60-569, Wielkopolska, Poznan, Poland.
| | - Marcin Grabicki
- Poznan University of Medical Sciences, Department of Pulmonology, Allergology and Respiratory Oncology, ul. Szamarzewskiego 84, 60-569, Wielkopolska, Poznan, Poland
| | - Tomasz Piorunek
- Poznan University of Medical Sciences, Department of Pulmonology, Allergology and Respiratory Oncology, ul. Szamarzewskiego 84, 60-569, Wielkopolska, Poznan, Poland
| | - Halina Batura-Gabryel
- Poznan University of Medical Sciences, Department of Pulmonology, Allergology and Respiratory Oncology, ul. Szamarzewskiego 84, 60-569, Wielkopolska, Poznan, Poland
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20
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King GG, Bates J, Berger KI, Calverley P, de Melo PL, Dellacà RL, Farré R, Hall GL, Ioan I, Irvin CG, Kaczka DW, Kaminsky DA, Kurosawa H, Lombardi E, Maksym GN, Marchal F, Oppenheimer BW, Simpson SJ, Thamrin C, van den Berge M, Oostveen E. Technical standards for respiratory oscillometry. Eur Respir J 2020; 55:13993003.00753-2019. [PMID: 31772002 DOI: 10.1183/13993003.00753-2019] [Citation(s) in RCA: 282] [Impact Index Per Article: 70.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 10/15/2019] [Indexed: 12/11/2022]
Abstract
Oscillometry (also known as the forced oscillation technique) measures the mechanical properties of the respiratory system (upper and intrathoracic airways, lung tissue and chest wall) during quiet tidal breathing, by the application of an oscillating pressure signal (input or forcing signal), most commonly at the mouth. With increased clinical and research use, it is critical that all technical details of the hardware design, signal processing and analyses, and testing protocols are transparent and clearly reported to allow standardisation, comparison and replication of clinical and research studies. Because of this need, an update of the 2003 European Respiratory Society (ERS) technical standards document was produced by an ERS task force of experts who are active in clinical oscillometry research.The aim of the task force was to provide technical recommendations regarding oscillometry measurement including hardware, software, testing protocols and quality control.The main changes in this update, compared with the 2003 ERS task force document are 1) new quality control procedures which reflect use of "within-breath" analysis, and methods of handling artefacts; 2) recommendation to disclose signal processing, quality control, artefact handling and breathing protocols (e.g. number and duration of acquisitions) in reports and publications to allow comparability and replication between devices and laboratories; 3) a summary review of new data to support threshold values for bronchodilator and bronchial challenge tests; and 4) updated list of predicted impedance values in adults and children.
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Affiliation(s)
- Gregory G King
- Dept of Respiratory Medicine and Airway Physiology and Imaging Group, Royal North Shore Hospital and The Woolcock Institute of Medical Research, The University of Sydney, Sydney, Australia
| | - Jason Bates
- Dept of Medicine, Pulmonary/Critical Care Division, University of Vermont, Larner College of Medicine, Burlington, VT, USA
| | - Kenneth I Berger
- Division of Pulmonary, Critical Care, and Sleep Medicine, NYU School of Medicine and André Cournand Pulmonary Physiology Laboratory, Belleuve Hospital, New York, NY, USA
| | - Peter Calverley
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Pedro L de Melo
- Institute of Biology and Faculty of Engineering, Department of Physiology, Biomedical Instrumentation Laboratory, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Raffaele L Dellacà
- Dipartimento di Elettronica, Informazione e Bioingegneria - DEIB, Politecnico di Milano University, Milano, Italy
| | - Ramon Farré
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona-IDIBAPS, Barcelona, Spain.,CIBER de Enfermedades Respiratorias, Madrid, Spain
| | - Graham L Hall
- Children's Lung Health, Telethon Kids Institute, School of Physiotherapy and Exercise Science, Curtin University, Perth, Australia
| | - Iulia Ioan
- Dept of Pediatric Lung Function Testing, Children's Hospital, Vandoeuvre-lès-Nancy, France.,EA 3450 DevAH - Laboratory of Physiology, Faculty of Medicine, University of Lorraine, Vandoeuvre-lès-Nancy, France
| | - Charles G Irvin
- Dept of Medicine, Pulmonary/Critical Care Division, University of Vermont, Larner College of Medicine, Burlington, VT, USA
| | - David W Kaczka
- Depts of Anesthesia, Biomedical Engineering and Radiology, University of Iowa, Iowa City, IA, USA
| | - David A Kaminsky
- Dept of Medicine, Pulmonary/Critical Care Division, University of Vermont, Larner College of Medicine, Burlington, VT, USA
| | - Hajime Kurosawa
- Dept of Occupational Health, Tohoku University School of Medicine, Sendai, Japan
| | - Enrico Lombardi
- Pediatric Pulmonary Unit, Meyer Pediatric University Hospital, Florence, Italy
| | - Geoffrey N Maksym
- School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada
| | - François Marchal
- Dept of Pediatric Lung Function Testing, Children's Hospital, Vandoeuvre-lès-Nancy, France.,EA 3450 DevAH - Laboratory of Physiology, Faculty of Medicine, University of Lorraine, Vandoeuvre-lès-Nancy, France
| | - Beno W Oppenheimer
- Division of Pulmonary, Critical Care, and Sleep Medicine, NYU School of Medicine and André Cournand Pulmonary Physiology Laboratory, Belleuve Hospital, New York, NY, USA
| | - Shannon J Simpson
- Children's Lung Health, Telethon Kids Institute, School of Physiotherapy and Exercise Science, Curtin University, Perth, Australia
| | - Cindy Thamrin
- Dept of Respiratory Medicine and Airway Physiology and Imaging Group, Royal North Shore Hospital and The Woolcock Institute of Medical Research, The University of Sydney, Sydney, Australia
| | - Maarten van den Berge
- University of Groningen, University Medical Center Groningen, Dept of Pulmonary Diseases, Groningen, The Netherlands
| | - Ellie Oostveen
- Dept of Respiratory Medicine, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium
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21
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Veneroni C, Dahl MJ, Lavizzari A, Dawson E, Rebentisch A, Studstill S, Bowen S, Albertine KH, Dellaca RL. Non-invasive measurements of respiratory system mechanical properties by the forced oscillation technique in spontaneously breathing, mixed-breed, normal term lambs from birth to five months of age. Physiol Meas 2019; 40:105007. [PMID: 31341100 DOI: 10.1088/1361-6579/ab3493] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE To provide a non-invasive approach to monitoring lung function in spontaneously breathing lambs, from birth to five months of life, by the forced oscillation technique (FOT). This report describes the experimental set-up, data processing, and identification of normal predicted values of resistance (Rrs) and reactance (Xrs) of the respiratory system, along with normal bronchodilator response for bronchial reversibility testing. APPROACH Rrs and Xrs at 5, 11, and 19 Hz were measured monthly for five months in 20 normal term lambs that breathed spontaneously. In seven lambs, repeated measurements also were made within the first month of life (at 3, 7, 14, and 21 d of life). We determined the repeatability and reproducibility of the measurements and characterized the relationship between lung mechanics and age, sex, and body dimensions, using regression analysis, and measured changes in lung mechanics in response to inhaled bronchodilator. MAIN RESULTS The measurements provided repeatable and reproducible data. Rrs decreased, whereas Xrs increased, with growth from birth through the first two months of life, after which no statistically significant differences were detected. We identified normal value equations for Rrs and Xrs and for each of the measured anthropometric variables. Respiratory system mechanics were not affected by the bronchodilator. SIGNIFICANCE The FOT provides reliable non-invasive measurement of respiratory system mechanics in spontaneously breathing term lambs from birth to five months of age. The methods and normal reference values defined in this study will facilitate testing of the pathophysiological consequences of preterm birth and prolonged respiratory support on respiratory system mechanics.
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Affiliation(s)
- Chiara Veneroni
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milano, Italy. Co-first and co-last authors. Author to whom any correspondence should be addressed
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22
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I Say IOS You Say AOS: Comparative Bias in Respiratory Impedance Measurements. Lung 2019; 197:473-481. [PMID: 31273438 PMCID: PMC6647162 DOI: 10.1007/s00408-019-00247-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/24/2019] [Indexed: 12/02/2022]
Abstract
Background The forced oscillation technique (FOT) measures respiratory impedance during normal tidal breathing and requires minimal patient cooperation. Objective To compare IOS and AOS devices in patients with asthma and COPD. Methods We compared two different FOT devices, namely impulse oscillometry using a loudspeaker (IOS: Jaeger Masterscreen) and airwave oscillometry using a vibrating mesh (AOS: Thorasys Tremoflo) for pre- and post-bronchodilator measurements in 84 patients with asthma and COPD. Results The overall pattern of measurement bias was for higher resistance with IOS and higher reactance with AOS, this being the case in asthma and COPD separately. There were small but significantly higher values using IOS for resistance at 5 Hz (R5) and 20(19) Hz (R20(19)). In converse, values for reactance at 5 Hz (X5), reactance area (AX) and resonant frequency (Fres) were significantly higher using AOS but to a much larger extent. The difference in AX between devices was more pronounced in COPD than in asthma. Salbutamol reversibility as % change was greater in asthma than COPD patients with AX but not FEV1. Conclusion Our study showed evidence of better agreement for resistance than reactance when comparing IOS and AOS, perhaps inferring that AOS may be more sensitive at measuring reactance in patients with airflow obstruction. Electronic supplementary material The online version of this article (10.1007/s00408-019-00247-y) contains supplementary material, which is available to authorised users.
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23
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Faria ACD, Carvalho ARS, Guimarães ARM, Lopes AJ, Melo PL. Association of respiratory integer and fractional-order models with structural abnormalities in silicosis. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2019; 172:53-63. [PMID: 30902127 DOI: 10.1016/j.cmpb.2019.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 01/23/2019] [Accepted: 02/06/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND AND OBJECTIVE Integer and fractional-order models have emerged as powerful methods for obtaining information regarding the anatomical or pathophysiological changes that occur during respiratory diseases. However, the precise interpretation of the model parameters in light of the lung structural changes is not known. This study analyzed the associations of the integer and fractional-order models with structural changes obtained using multidetector computed tomography densitometry (MDCT) and pulmonary function analysis. METHODS Integer and fractional-order models were adjusted to data obtained using the forced oscillation technique (FOT). The results obtained in controls (n = 20) were compared with those obtained in patients with silicosis (n = 32), who were submitted to spirometry, body plethysmograph, FOT, diffusing capacity of the lungs for carbon monoxide (DLCO), and MDCT. The diagnostic accuracy was also investigated using ROC analysis. RESULTS The observed changes in the integer and fractional-order models were consistent with the pathophysiology of silicosis. The integer-order model showed association only between inertance and the non-aerated compartment (R = -0.69). This parameter also presented the highest associations with spirometry (R = 0.81), plethysmography (-0.61) and pulmonary diffusion (R = 0.53). Considering the fractional-order model, the increase in the poorly aerated and non-aerated regions presented direct correlations with the fractional inertance (R = 0.48), respiratory damping (R = 0.37) and hysteresivity (R = 0.54) and inverse associations with its fractional exponent (R = -0.62) and elastance (-0.35). Significant associations were also observed with spirometry (R = 0.63), plethysmography (0.37) and pulmonary diffusion (R = 0.51). Receiver operator characteristic analysis showed a higher accuracy in the FrOr model (0.908) than the eRIC model (0.789). CONCLUSIONS Our study has shown clear associations of the integer and fractional-order parameters with anatomical changes obtained via MDCT and pulmonary function measurements. These findings help to elucidate the physiological interpretation of the integer and fractional-order parameters and provide evidence that these parameters are reflective of the abnormal changes in silicosis. We also observed that the fractional-order model showed smaller curve-fitting errors, which resulted in a higher diagnostic accuracy than that of the eRIC model. Taken together, these results provide strong motivation for further studies exploring the clinical and scientific use of these models in respiratory medicine.
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Affiliation(s)
- Alvaro C D Faria
- Biomedical Instrumentation Laboratory, Institute of Biology Roberto Alcantara Gomes, State University of Rio de Janeiro, Rio de Janeiro, Brazil; Laboratory of Clinical and Experimental Research in Vascular Biology (BioVasc), State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Alysson Roncally Silva Carvalho
- Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Laboratory of Pulmonary Engineering, Biomedical Engineering Program, Alberto Luis Coimbra Institute of Postgraduation and Research in Engineering, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Alan Ranieri Medeiros Guimarães
- Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Laboratory of Pulmonary Engineering, Biomedical Engineering Program, Alberto Luis Coimbra Institute of Postgraduation and Research in Engineering, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Agnaldo J Lopes
- Pulmonary Function Laboratory, Pedro Ernesto University Hospital, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Pedro L Melo
- Biomedical Instrumentation Laboratory, Institute of Biology Roberto Alcantara Gomes, State University of Rio de Janeiro, Rio de Janeiro, Brazil; Laboratory of Clinical and Experimental Research in Vascular Biology (BioVasc), State University of Rio de Janeiro, Rio de Janeiro, Brazil.
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24
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Alamdari HH, El-Sankary K, Maksym GN. Time-Varying Respiratory Mechanics as a Novel Mechanism Behind Frequency Dependence of Impedance: A Modeling Approach. IEEE Trans Biomed Eng 2019; 66:2433-2446. [PMID: 30596567 DOI: 10.1109/tbme.2018.2890055] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Frequency dependence of respiratory mechanics is a well-established behavior of the respiratory system and is known to be an indicator of severity of obstructive disease, attributed to both tissue viscoelasticity and heterogeneity of airflow in the lung. Despite the fact that respiratory parameters are known to vary in time, often amplified in disease, all analysis methods assume stationarity or short-time stationarity in the parameters used to describe the respiratory system, and the effects of this assumption have not yet been examined in any detail. Here, using a generalized approach, we developed a theory for time-varying respiratory mechanics in time-frequency domain for analysis of linear time-varying systems, then, we analyzed the same respiratory system model with time-varying parameters in the time domain. Both time-frequency domain and time-domain derivations revealed a striking correlation between time-varying behavior of the respiratory system and frequency dependence of resistance. Remarkably, this phenomenon arose from the amplitude of time variations of the elastance. This links two mechanisms that are known to increase in obstructive disease: apparent low frequency increases in resistance and the time variations of reactance.
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Longitudinal changes in pulmonary function and respiratory impedance of rheumatoid arthritis. Respir Physiol Neurobiol 2018; 261:1-8. [PMID: 30583069 DOI: 10.1016/j.resp.2018.12.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/14/2018] [Accepted: 12/21/2018] [Indexed: 11/20/2022]
Abstract
The aim of this study was to examine long-term changes in pulmonary function and respiratory impedance (Zrs) as assessed by forced oscillation technique (FOT) of rheumatoid arthritis (RA)-related pulmonary disorders. Data of 42 RA patients who underwent pulmonary function tests and Zrs measurements at least twice at a >900-day interval were retrospectively reviewed. Zrs, respiratory resistance (Rrs) and reactance (Xrs), were measured as a function of oscillatory frequency from 4 to 36 Hz. The Rrs and difference between inspiratory and expiratory phases of Xrs were significantly decreased. Annual changes in Xrs parameters significantly correlated with those of spirometric parameters. Zrs parameters were significantly different between the low (the lower 75 percentile of incidence) and high (the top quartile) frequency of adverse respiratory event groups. The Zrs combined with spirometry may be beneficial to evaluate alterations in respiratory functions of RA.
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Comparison of two methods of determining lung de-recruitment, using the forced oscillation technique. Eur J Appl Physiol 2018; 118:2213-2224. [PMID: 30062516 DOI: 10.1007/s00421-018-3949-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 07/21/2018] [Indexed: 10/28/2022]
Abstract
Airway closure has proved to be important in a number of respiratory diseases and may be the primary functional defect in asthma. A surrogate measure of closing volume can be identified using the forced oscillation technique (FOT), by performing a deflation maneuver and examining the resultant reactance (Xrs) lung volume relationship. This study aims to determine if a slow vital capacity maneuver can be used instead of this deflation maneuver and compare it to existing more complex techniques. Three subject groups were included in the study; healthy (n = 29), asthmatic (n = 18), and COPD (n = 10) for a total of 57 subjects. Reactance lung volume curves were generated via FOT recordings during two different breathing manoeuvres (both pre and post bronchodilator). The correlation and agreement between surrogate closing volume (Volcrit) and reactance (Xrscrit) at this volume was analysed. The changes in Volcrit and Xrscrit pre and post bronchodilator were also analysed. Across all three subject groups, the two different measures of Volcrit were shown to be statistically equivalent (p > 0.05) and demonstrated a strong fit to the data (R2 = 0.49, 0.78, 0.59, for asthmatic, COPD and healthy subject groups, respectively). A bias was evident between the two measurements of Xrscrit with statistically different means (p < 0.05). However, the two measurements of Xrscrit displayed the same trends. In conclusion, we have developed an alternative technique for measuring airway closure from FOT recordings. The technique delivers equivalent and possibly more sensitive results to previous methods while being simple and easily performed by the patient.
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What can we learn about COPD from impulse oscillometry? Respir Med 2018; 139:106-109. [PMID: 29857993 DOI: 10.1016/j.rmed.2018.05.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/14/2018] [Accepted: 05/06/2018] [Indexed: 11/24/2022]
Abstract
Impulse oscillometry (IOS) is the most commonly used type of forced oscillation technique in clinical practice, although relatively little is known about its application in COPD. Resistance at 20 Hz (R20) is unrelated to COPD severity and does not improve with bronchodilatation or bronchoconstriction, inferring a lack of large airway involvement in COPD. Peripheral airway resistance expressed as frequency dependent heterogeneity between 5 Hz and 20 Hz (R5-R20), and peripheral airway compliance as area under the reactance curve (AX), are both closely related to COPD severity and exacerbations. Both R5-R20 and AX markedly improve in response to long acting bronchodilators, while AX appears to be more sensitive than R5-R20 in response to bronchoconstriction. Future studies may be directed to assess if IOS in combination with spirometry is more sensitive at predicting future exacerbations. Perhaps AX might also be useful as a screening tool in early stage disease or to monitor long term decline in COPD.
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Linhas R, Lima F, Coutinho D, Almeida J, Neves S, Oliveira A, Ladeira I, Lima R, Campainha S, Guimarães M. Role of the impulse oscillometry in the evaluation of tracheal stenosis. Pulmonology 2018; 24:224-230. [PMID: 29627402 DOI: 10.1016/j.pulmoe.2017.12.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 11/26/2017] [Accepted: 12/11/2017] [Indexed: 10/17/2022] Open
Abstract
INTRODUCTION AND OBJECTIVES Tracheal stenosis is a rare and challenging disease. Bronchoscopy is the gold standard for diagnosis and assessment but brings inherent risks. Spirometry is commonly used to access obstructions but is not always feasible due to patient related factors. We therefore considered impulse oscillometry (IOS) as a non-invasive method to quantify airway obstruction and its potential use for diagnosis and follow-up of tracheal stenosis. MATERIALS AND METHODS Patients with confirmed tracheal stenosis were recruited between January 1st, 2015 and December 31st, 2016. Before bronchoscopy, all subjects underwent IOS and spirometry; for patients submitted to interventional bronchoscopy the same techniques were also performed after the procedure. We assessed the correlation between IOS measurements and airway narrowing as well as between IOS and spirometry values. RESULTS Twenty-one patients were included. Tracheal narrowing was inversely correlated with X5% (r -0.442, p 0.045) and positively correlated with FEV1/PEF (r 0.467, p 0.033). The stenosis length was inversely correlated with PEF and PEF% (r -0.729, p=0.001 and r -0.707, p=0.002, respectively). There was a strong correlation between spirometric and IOS values. We did not find any significant differences between pre- and post-intervention IOS values for patients assessed after interventional bronchoscopy. CONCLUSIONS Our study showed a weak correlation between X5% and tracheal narrowing making it unclear whether IOS can be used for physiological assessment of patients with tracheal stenosis. Stenosis length correlated with PEF making it a potential predictor of successful surgical approach. The correlation between IOS and spirometric values makes IOS a potential alternative in patients with suspected tracheal stenosis who are not able to perform spirometry. Larger scale studies should clarify the role of IOS in this pathology.
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Affiliation(s)
- R Linhas
- Department of Pulmonology, Centro Hospitalar Vila Nova de Gaia/Espinho, EPE, Portugal.
| | - F Lima
- Department of Pulmonology, Centro Hospitalar Vila Nova de Gaia/Espinho, EPE, Portugal
| | - D Coutinho
- Bronchoscopy Unit, Centro Hospitalar de Vila Nova de Gaia/Espinho, EPE, Portugal
| | - J Almeida
- Bronchoscopy Unit, Centro Hospitalar de Vila Nova de Gaia/Espinho, EPE, Portugal
| | - S Neves
- Bronchoscopy Unit, Centro Hospitalar de Vila Nova de Gaia/Espinho, EPE, Portugal
| | - A Oliveira
- Bronchoscopy Unit, Centro Hospitalar de Vila Nova de Gaia/Espinho, EPE, Portugal
| | - I Ladeira
- Respiratory Physiopathology Laboratory, Centro Hospitalar de Vila Nova de Gaia/Espinho, EPE, Portugal
| | - R Lima
- Respiratory Physiopathology Laboratory, Centro Hospitalar de Vila Nova de Gaia/Espinho, EPE, Portugal
| | - S Campainha
- Bronchoscopy Unit, Centro Hospitalar de Vila Nova de Gaia/Espinho, EPE, Portugal
| | - M Guimarães
- Respiratory Physiopathology Laboratory, Centro Hospitalar de Vila Nova de Gaia/Espinho, EPE, Portugal
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Forty years of reference values for respiratory system impedance in adults: 1977–2017. Respir Med 2018; 136:37-47. [DOI: 10.1016/j.rmed.2018.01.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 01/22/2018] [Accepted: 01/27/2018] [Indexed: 11/22/2022]
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Zannin E, Dellaca' RL, Dognini G, Marconi L, Perego M, Pillow JJ, Tagliabue PE, Ventura ML. Effect of frequency on pressure cost of ventilation and gas exchange in newborns receiving high-frequency oscillatory ventilation. Pediatr Res 2017; 82:994-999. [PMID: 28665929 DOI: 10.1038/pr.2017.151] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 06/09/2017] [Indexed: 11/09/2022]
Abstract
BackgroundWe hypothesized that ventilating at the resonant frequency of the respiratory system optimizes gas exchange while limiting the mechanical stress to the lung in newborns receiving high-frequency oscillatory ventilation (HFOV). We characterized the frequency dependence of oscillatory mechanics, gas exchange, and pressure transmission during HFOV.MethodsWe studied 13 newborn infants with a median (interquartile range) gestational age of 29.3 (26.4-30.4) weeks and body weight of 1.00 (0.84-1.43) kg. Different frequencies (5, 8, 10, 12, and 15 Hz) were tested, keeping carbon dioxide diffusion coefficient (DCO2) constant. Oscillatory mechanics and transcutaneous blood gas were measured at each frequency. The attenuation of pressure swings (ΔP) from the airways opening to the distal end of the tracheal tube (TT) and to the alveolar compartment was mathematically estimated.ResultsBlood gases were unaffected by frequency. The mean (SD) resonant frequency was 16.6 (3.5) Hz. Damping of ΔP increased with frequency and with lung compliance. ΔP at the distal end of the TT was insensitive to frequency, whereas ΔP at the peripheral level decreased with frequency.ConclusionThere is no optimal frequency for gas exchange when DCO2 is held constant. Greater attenuation of oscillatory pressure at higher frequencies offers more protection from barotrauma, especially in patients with poor compliance.
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Affiliation(s)
- Emanuela Zannin
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di, Milano University, Milan, Italy
| | - Raffaele L Dellaca'
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di, Milano University, Milan, Italy
| | - Giulia Dognini
- Obstetric and Pediatric Department, Neonatal Intensive Care Unit, Fondazione MBBM-ASST, Monza, Italy
| | - Lara Marconi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di, Milano University, Milan, Italy
| | - Martina Perego
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di, Milano University, Milan, Italy
| | - Jane J Pillow
- Centre for Neonatal Research and Education, School of Anatomy, Physiology and Human Biology, University of Western Australia, Perth, WA, Australia
| | - Paolo E Tagliabue
- Obstetric and Pediatric Department, Neonatal Intensive Care Unit, Fondazione MBBM-ASST, Monza, Italy
| | - Maria Luisa Ventura
- Obstetric and Pediatric Department, Neonatal Intensive Care Unit, Fondazione MBBM-ASST, Monza, Italy
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Responsiveness to bronchodilator procaterol in COPD as assessed by forced oscillation technique. Respir Physiol Neurobiol 2017; 240:41-47. [PMID: 28238903 DOI: 10.1016/j.resp.2017.02.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/21/2017] [Indexed: 12/23/2022]
Abstract
The aim of this retrospective study was to assess responses to a bronchodilator by forced oscillation technique (FOT) and to relate the results of respiratory impedance (Zrs) to spirometric parameters in patients with chronic obstructive pulmonary disease (COPD). Zrs was measured as a function of frequency from 4 to 36Hz before and after inhalation of procaterol, a short-acting β2-agonist (n=60). Respiratory resistance (Rrs) and reactance (Xrs) were significantly frequency-dependent, and inspiratory and expiratory phases were different both before and after procaterol inhalation. The Rrs at 4Hz and Xrs at 4-20Hz during a whole breath were significantly improved after procaterol inhalation. The response to procaterol inhalation varied among patients, and changes in Xrs at 4Hz significantly correlated with% change in forced expiratory volume in one second and changes in forced vital capacity. Taken together, Zrs, and specifically Xrs parameters, are sensitive to acute physiological responses to a bronchodilator in COPD.
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Lorx A, Czövek D, Gingl Z, Makan G, Radics B, Bartusek D, Szigeti S, Gál J, Losonczy G, Sly PD, Hantos Z. Airway dynamics in COPD patients by within-breath impedance tracking: effects of continuous positive airway pressure. Eur Respir J 2017; 49:49/2/1601270. [DOI: 10.1183/13993003.01270-2016] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 11/08/2016] [Indexed: 11/05/2022]
Abstract
Tracking of the within-breath changes of respiratory mechanics using the forced oscillation technique may provide outcomes that characterise the dynamic behaviour of the airways during normal breathing.We measured respiratory resistance (Rrs) and reactance (Xrs) at 8 Hz in 55 chronic obstructive pulmonary disease (COPD) patients and 20 healthy controls, and evaluated Rrs and Xrs as functions of gas flow (V′) and volume (V) during normal breathing cycles. In 12 COPD patients, additional measurements were made at continuous positive airway pressure (CPAP) levels of 4, 8, 14 and 20 hPa.The Rrs and Xrsversus V′ and V relationships displayed a variety of loop patterns, allowing characterisation of physiological and pathological processes. The main outcomes emerging from the within-breath analysis were the Xrsversus V loop area (AXV) quantifying expiratory flow limitation, and the tidal change in Xrs during inspiration (ΔXI) reflecting alteration in lung inhomogeneity in COPD. With increasing CPAP, AXV and ΔXI approached the normal ranges, although with a large variability between individuals, whereas mean Rrs remained unchanged.Within-breath tracking of Rrs and Xrs allows an improved assessment of expiratory flow limitation and functional inhomogeneity in COPD; thereby it may help identify the physiological phenotypes of COPD and determine the optimal level of respiratory support.
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Zannin E, Doni D, Ventura ML, Fedeli T, Rigotti C, Dellacá RL, Tagliabue PE. Relationship between Mean Airways Pressure, Lung Mechanics, and Right Ventricular Output during High-Frequency Oscillatory Ventilation in Infants. J Pediatr 2017; 180:110-115. [PMID: 27745747 DOI: 10.1016/j.jpeds.2016.09.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 07/28/2016] [Accepted: 09/08/2016] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To characterize changes in lung mechanics and right ventricular output (RVO) during incremental/decremental continuous distending pressure (CDP) maneuvers in newborn infants receiving high-frequency oscillatory ventilation, with the aim of evaluating when open lung maneuvers are needed and whether they are beneficial. STUDY DESIGN Thirteen infants on high-frequency oscillatory ventilation were studied with a median (IQR) gestational age of 261 (253-291) weeks and median (IQR) body weight of 810 (600-1020) g. CDP was increased stepwise from 8 cmH2O to a maximum pressure and subsequently decreased until oxygenation deteriorated or a CDP of 8 cmH2O was reached. The lowest CDP that maintained good oxygenation was considered the clinically optimal CDP. At each CDP, the following variables were evaluated: oxygenation, respiratory system reactance (Xrs), and RVO by Doppler echocardiography. RESULTS At maximal CDP reached during the trial, 19 [1] cmH2O (mean [SEM]), oxygenation markedly improved, and Xrs and RVO decreased. During deflation, oxygenation remained stable over a wide range of CDP settings, Xrs returned to the baseline values, and RVO increased but the baseline values were not readily restored in all patients. CONCLUSION These results suggest that Xrs and RVO are more sensitive than oxygenation to overdistension and they may be useful in clinical practice to guide open lung maneuvers.
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Affiliation(s)
- Emanuela Zannin
- Department of Electronics, Informatics and Bioengineering, Politecnico di Milano University, Milan, Italy
| | - Daniela Doni
- Neonatal Intensive Care Unit, Fondazione MBBM, Monza, Italy
| | | | - Tiziana Fedeli
- Neonatal Intensive Care Unit, Fondazione MBBM, Monza, Italy
| | | | - Raffaele L Dellacá
- Department of Electronics, Informatics and Bioengineering, Politecnico di Milano University, Milan, Italy
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Gochicoa-Rangel L, Vargas MH, Alonso-Gómez JL, Rodríguez-Moreno L, Martínez-Briseño D, Baños-Mejía O, Torre-Bouscoulet L. Respiratory impedance in patients with Duchenne muscular dystrophy. Pediatr Pulmonol 2016; 51:1072-1079. [PMID: 27129130 DOI: 10.1002/ppul.23434] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 01/09/2016] [Accepted: 02/23/2016] [Indexed: 12/27/2022]
Abstract
UNLABELLED Impulse oscillometry (IOS) evaluates non-effort-dependent respiratory mechanics, and thus it may be useful to evaluate patients with Duchenne muscular dystrophy (DMD). OBJECTIVES We aimed (1) to describe the behavior of IOS parameters in patients with DMD, and compare it to those from a control group; (2) to determine whether resistances and reactances differ in relation to the severity of DMD; and (3) to compare IOS parameters with spirometry and maximal inspiratory (MIP) and expiratory (MEP) pressures. METHODS Children and adolescents (<20 years old) with biopsy-confirmed DMD and age-paired subjects were cross-sectionally evaluated. All results were transformed to z scores with respect to the healthy subjects (reference population). RESULTS Anthropometric characteristics did not differ between the 31 patients and 69 controls included in the study. Compared with controls, patients with DMD had higher IOS resistances and lower reactances. As expected, FEV1 and FVC were lower in patients and always declined as age increased. By contrast, MIP and MEP were lower-than-normal in youngest patients, tended to improve around puberty initiation, and declined thereafter. In general, there was a poor correlation between IOS parameters and spirometric variables or respiratory pressures, excepting for X20 Hz, which had an inverse correlation with FEV1 . Interestingly, IOS resistances were higher in patients with less disability (lower Vignos score; better FVC), but tended to be normalized in advanced stages of the disease. CONCLUSION This study showed that IOS is feasible in children and adolescents with DMD and yields information about respiratory function not achievable with the usual forced techniques. Pediatr Pulmonol. 2016;51:1072-1079. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Laura Gochicoa-Rangel
- Departamento de Fisiología Respiratoria, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Calzada de Tlalpan 4502, Colonia Sección XVI, CP 14080, México DF, México.,Centro de Evaluación del Paciente Asmático Infantil, Centro Médico Santa Teresa, Texcoco, Estado de México, México
| | - Mario H Vargas
- Departamento de Investigación en Hiperreactividad Bronquial, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", México DF, México
| | - José Luis Alonso-Gómez
- Departamento de Fisiología Respiratoria, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Calzada de Tlalpan 4502, Colonia Sección XVI, CP 14080, México DF, México
| | - Luis Rodríguez-Moreno
- Centro de Evaluación del Paciente Asmático Infantil, Centro Médico Santa Teresa, Texcoco, Estado de México, México
| | - David Martínez-Briseño
- Departamento de Epidemiología y Ciencias Sociales en Salud, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", México DF, México
| | - Omar Baños-Mejía
- Departamento de Rehabilitación Pulmonar, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", México DF, México
| | - Luis Torre-Bouscoulet
- Departamento de Fisiología Respiratoria, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Calzada de Tlalpan 4502, Colonia Sección XVI, CP 14080, México DF, México.
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Abstract
Measurements of resonant frequencies in the human chest, and of how resonant frequency varies with the subject's mass, height, chest size and sex, were undertaken as a pilot study on a sample of 15 volunteers. These were obtained by measuring the acceleration response of the chest when a force was applied to the back at a range of frequencies, and noting the peak response frequency. It is foreseen that mechanical stimulation of the chest at the appropriate frequency might form a useful part of physiotherapy treatment offered to patients with particular chest disorders. The results suggest that the chest resonant frequency is sensitive to the subject's mass and chest size, but is less dependent on height. Typical values found were 25 Hz for males and 33 Hz for females.
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Affiliation(s)
- M J Goodwin
- School of Engineering, Staffordshire University
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Czövek D, Shackleton C, Hantos Z, Taylor K, Kumar A, Chacko A, Ware RS, Makan G, Radics B, Gingl Z, Sly PD. Tidal changes in respiratory resistance are sensitive indicators of airway obstruction in children. Thorax 2016; 71:907-15. [PMID: 27178219 DOI: 10.1136/thoraxjnl-2015-208182] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 04/17/2016] [Indexed: 11/04/2022]
Abstract
RATIONALE Individual assessment of airway obstruction in preschool-age children requires sensitive and specific lung function methods with low demand of cooperation. Although the forced oscillation technique (FOT) is feasible in young children, conventional measurements of respiratory impedance (Zrs) have limited diagnostic power in individuals. OBJECTIVE To find descriptors of within-breath Zrs that are sensitive indicators of airway obstruction during tidal breathing in children. METHODS Zrs was measured with (i) a standard multifrequency FOT (4-26 Hz) to assess the mean values of resistance and reactance for whole breaths and (ii) a 10 Hz signal to track the within-breath changes. Various Zrs measures obtained in healthy children (n=75) and those with acute wheeze (n=31) were investigated with receiver operator characteristic (ROC) analysis. The cut-off values obtained for airway obstruction were then tested in children with recurrent wheeze (n=20) before and after administration of salbutamol. RESULTS The largest area under the ROC curve (0.95) was observed for the tidal changes of resistance between the zero-flow values (ΔR). The ΔR cut-off value of 1.42 hPa s/L detected airway obstruction with sensitivity of 92% and specificity of 89% in children with acute wheeze and distinguished children with recurrent wheeze (16/20 above the cut-off value) from healthy children (22/23 below the cut-off value). Furthermore, ΔR significantly decreased after salbutamol in wheezy children but remained unchanged in healthy children. CONCLUSIONS New lung function measure ΔR is able to detect airway obstruction with high sensitivity and specificity and is suitable for use in lung function testing in young children.
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Affiliation(s)
- Dorottya Czövek
- Children's Lung, Environment and Asthma Research Team, University of Queensland, Brisbane, Queensland, Australia Child Health Research Centre, University of Queensland, Brisbane, Queensland, Australia
| | - Claire Shackleton
- Children's Lung, Environment and Asthma Research Team, University of Queensland, Brisbane, Queensland, Australia Child Health Research Centre, University of Queensland, Brisbane, Queensland, Australia
| | - Zoltán Hantos
- Children's Lung, Environment and Asthma Research Team, University of Queensland, Brisbane, Queensland, Australia Child Health Research Centre, University of Queensland, Brisbane, Queensland, Australia Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary Department of Pulmonology, University of Szeged, Szeged, Hungary
| | - Kate Taylor
- Children's Lung, Environment and Asthma Research Team, University of Queensland, Brisbane, Queensland, Australia
| | - Anushma Kumar
- Children's Lung, Environment and Asthma Research Team, University of Queensland, Brisbane, Queensland, Australia
| | - Archana Chacko
- Children's Lung, Environment and Asthma Research Team, University of Queensland, Brisbane, Queensland, Australia
| | - Robert S Ware
- Child Health Research Centre, University of Queensland, Brisbane, Queensland, Australia
| | - Gergely Makan
- Department of Technical Informatics, University of Szeged, Szeged, Hungary
| | - Bence Radics
- Department of Pulmonology, University of Szeged, Szeged, Hungary
| | - Zoltán Gingl
- Department of Technical Informatics, University of Szeged, Szeged, Hungary
| | - Peter D Sly
- Children's Lung, Environment and Asthma Research Team, University of Queensland, Brisbane, Queensland, Australia Child Health Research Centre, University of Queensland, Brisbane, Queensland, Australia
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Faria ACD, Veiga J, Lopes AJ, Melo PL. Forced oscillation, integer and fractional-order modeling in asthma. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2016; 128:12-26. [PMID: 27040828 DOI: 10.1016/j.cmpb.2016.02.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 01/04/2016] [Accepted: 02/16/2016] [Indexed: 06/05/2023]
Abstract
The purpose of this study was to evaluate the use of fractional-order (FrOr) modeling in asthma. To this end, three FrOr models were compared with traditional parameters and an integer-order model (InOr). We investigated which model would best fit the data, the correlation with traditional lung function tests and the contribution to the diagnostic of airway obstruction. The data consisted of forced oscillation (FO) measurements obtained from healthy (n=22) and asthmatic volunteers with mild (n=22), moderate (n=19) and severe (n=19) obstructions. The first part of this study showed that a FrOr was the model that best fit the data (relative distance: FrOr=4.3±2.4; InOr=5.1±2.6%). The correlation analysis resulted in reasonable (R=0.36) to very good (R=0.77) associations between FrOr parameters and spirometry. The closest associations were observed between parameters related to peripheral airway obstruction, showing a clear relationship between the FrOr models and lung mechanics. Receiver-operator analysis showed that FrOr parameters presented a high potential to contribute to the detection of the mild obstruction in a clinical setting. The accuracy [area under the Receiver Operating Characteristic curve (AUC)] observed in these parameters (AUC=0.954) was higher than that observed in traditional FO parameters (AUC=0.732) and that obtained from the InOr model (AUC=0.861). Patients with moderate and severe obstruction were identified with high accuracy (AUC=0.972 and 0.977, respectively). In conclusion, the results obtained are in close agreement with asthma pathology, and provide evidence that FO measurement associated with FrOr models is a non-invasive, simple and radiation-free method for the detection of biomechanical abnormalities in asthma.
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Affiliation(s)
- Alvaro C D Faria
- Biomedical Instrumentation Laboratory, Institute of Biology Roberto Alcantara Gomes and Laboratory of Clinical and Experimental Research in Vascular Biology (BioVasc), State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Juliana Veiga
- Biomedical Instrumentation Laboratory, Institute of Biology Roberto Alcantara Gomes and Laboratory of Clinical and Experimental Research in Vascular Biology (BioVasc), State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Agnaldo J Lopes
- Pulmonary Function Laboratory, Pedro Ernesto University Hospital, Brazil
| | - Pedro L Melo
- Biomedical Instrumentation Laboratory, Institute of Biology Roberto Alcantara Gomes and Laboratory of Clinical and Experimental Research in Vascular Biology (BioVasc), State University of Rio de Janeiro, Rio de Janeiro, Brazil.
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Sokai R, Ito S, Iwano S, Uchida A, Aso H, Kondo M, Ishiguro N, Kojima T, Hasegawa Y. Respiratory mechanics measured by forced oscillation technique in rheumatoid arthritis-related pulmonary abnormalities: frequency-dependence, heterogeneity and effects of smoking. SPRINGERPLUS 2016; 5:335. [PMID: 27064652 PMCID: PMC4792822 DOI: 10.1186/s40064-016-1952-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 02/29/2016] [Indexed: 11/10/2022]
Abstract
Rheumatoid arthritis (RA)-related pulmonary disorders specifically airway abnormalities and interstitial pneumonia (IP) are important extra-articular manifestations. The forced oscillation technique (FOT) is a useful method to assess respiratory impedance, respiratory resistance (Rrs) and reactance (Xrs), at different oscillatory frequencies during tidal breathing. The aim of this study was to characterize the respiratory mechanics of patients with RA and to relate them to parameters of the pulmonary function test and findings of chest CT images. Respiratory impedance of RA patients (n = 69) was measured as a function of frequency from 4 to 36 Hz using the FOT device and compared with that of healthy subjects (n = 10). Data were retrospectively reviewed. Patients were female-dominant (60.9 %) and 95.7 % had abnormal CT findings including airway and parenchymal abnormalities. Thirty-seven of 69 patients (53.6 %) were smokers. Rrs was significantly frequency-dependent in RA patients but not in the healthy subjects. Xrs were significantly frequency-dependent in both RA and healthy groups. Rrs was significantly higher during an expiratory phase in both RA and healthy groups. Xrs was significantly lower (more negative) during an expiratory phase than that during an inspiratory phase in RA patients but not in healthy subjects. Xrs of the RA group was significantly more negative than that of the normal control. There was no difference in impedance parameters between the airway lesion dominant (n = 27) and IP dominant groups (n = 23) in the RA group. The impedance parameters of the RA group significantly correlated with most parameters of the pulmonary function test. In pulmonary function test results, % of the predicted value for forced expiratory flow from 25 to 75 % of forced vital capacity was significantly lower and % of the predicted value for diffusing capacity of the lung for carbon monoxide was higher in the airway lesion dominant group than those in the IP dominant group. Krebs von den Lungen-6, a serum indicator of IP, was significantly higher in the IP group than that in the airway lesion dominant group. Taken together, the impedance results reflect abnormalities in pulmonary functions and structures in patients with RA.
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Affiliation(s)
- Risa Sokai
- Department of Respiratory Medicine, Nagoya University School of Medicine, Nagoya, 466-8550 Japan
| | - Satoru Ito
- Department of Respiratory Medicine, Nagoya University School of Medicine, Nagoya, 466-8550 Japan
| | - Shingo Iwano
- Department of Radiology, Nagoya University School of Medicine, Nagoya, 466-8550 Japan
| | - Akemi Uchida
- Department of Clinical Laboratory, Nagoya University School of Medicine, Nagoya, 466-8550 Japan
| | - Hiromichi Aso
- Department of Respiratory Medicine, Nagoya University School of Medicine, Nagoya, 466-8550 Japan
| | - Masashi Kondo
- Department of Respiratory Medicine, Nagoya University School of Medicine, Nagoya, 466-8550 Japan
| | - Naoki Ishiguro
- Department of Orthopedic Surgery and Rheumatology, Nagoya University School of Medicine, Nagoya, 466-8550 Japan
| | - Toshihisa Kojima
- Department of Orthopedic Surgery and Rheumatology, Nagoya University School of Medicine, Nagoya, 466-8550 Japan
| | - Yoshinori Hasegawa
- Department of Respiratory Medicine, Nagoya University School of Medicine, Nagoya, 466-8550 Japan
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Ghafarian P, Jamaati H, Hashemian SM. A Review on Human Respiratory Modeling. TANAFFOS 2016; 15:61-69. [PMID: 27904536 PMCID: PMC5127616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Input impedance of the respiratory system is measured by forced oscillation technique (FOT). Multiple prior studies have attempted to match the electromechanical models of the respiratory system to impedance data. Since the mechanical behavior of airways and the respiratory system as a whole are similar to an electrical circuit in a combination of series and parallel formats some theories were introduced according to this issue. It should be noted that, the number of elements used in these models might be less than those required due to the complexity of the pulmonary-chest wall anatomy. Various respiratory models have been proposed based on this idea in order to demonstrate and assess the different parts of respiratory system related to children and adults data. With regard to our knowledge, some of famous respiratory models in related to obstructive, restrictive diseases and also Acute Respiratory Distress Syndrome (ARDS) are reviewed in this article.
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Affiliation(s)
- Pardis Ghafarian
- Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran,, PET/CT and Cyclotron Center, NRITLD, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamidreza Jamaati
- Tobacco Prevention and Control Research Center, NRITLD, Shahid Beheshti University of Medical Sciences, Tehran, Iran,Correspondence to: Jamaati HR, Address: Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), ShahidBeheshti University of Medical Sciences, Tehran, Iran, Email address:
| | - Seyed Mohammadreza Hashemian
- Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Ioan I, Coutier L, Bonabel C, Albrecht J, Demoulin B, Marchal F, Schweitzer C, Varechova S. Airway obstruction, upper airway artifact and response to bronchodilator in asthmatic and healthy children. Pediatr Pulmonol 2015; 50:1053-9. [PMID: 25384559 DOI: 10.1002/ppul.23131] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 05/28/2014] [Accepted: 07/31/2014] [Indexed: 11/06/2022]
Abstract
BACKGROUND The forced oscillation technique (FOT) may be affected by the upper airway artifact in children with airway obstruction. The aim was to test the impact of the artifact on FOT ability to diagnose asthma in children as recommended by current guidelines. METHODS The FOT was performed in 58 asthmatics and 27 controls before and after salbutamol. Respiratory resistance (Rrs) was measured at 8 Hz with a standard generator (SG), and a head generator (HG) that minimizes the upper airway artifact. The response to salbutamol was computed as change in respiratory resistance (Δ%Rrs) and admittance (Δ%Ars) that almost cancels the effect of the upper airway artifact. RESULTS Rrs and Δ%Rrs were significantly larger in patients than controls by HG (respectively P < 0.001 and P = 0.002) but not SG, while Δ%Ars was larger in asthma than control by both (P < 0.04). Best discriminators between patients and controls were Rrs or Δ%Rrs by HG and Δ%Ars by SG. CONCLUSION In asthmatic children, the upper airway artifact significantly impacts FOT measurements. The diagnostic value may be improved by minimization of the shunt, such as the computation of Δ%Ars.
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Affiliation(s)
- Iulia Ioan
- Service d'explorations fonctionnelles pédiatriques, Hôpital d'enfants, CHU de Nancy, France
| | - Laurianne Coutier
- EA 3450 DevAH-Laboratoire de Physiologie, Faculté de Médecine, Université Lorraine, Vandoeuvre, France
| | - Claude Bonabel
- Service d'explorations fonctionnelles pédiatriques, Hôpital d'enfants, CHU de Nancy, France.,EA 3450 DevAH-Laboratoire de Physiologie, Faculté de Médecine, Université Lorraine, Vandoeuvre, France
| | - Joris Albrecht
- EA 3450 DevAH-Laboratoire de Physiologie, Faculté de Médecine, Université Lorraine, Vandoeuvre, France
| | - Bruno Demoulin
- EA 3450 DevAH-Laboratoire de Physiologie, Faculté de Médecine, Université Lorraine, Vandoeuvre, France
| | - François Marchal
- Service d'explorations fonctionnelles pédiatriques, Hôpital d'enfants, CHU de Nancy, France.,EA 3450 DevAH-Laboratoire de Physiologie, Faculté de Médecine, Université Lorraine, Vandoeuvre, France
| | - Cyril Schweitzer
- Service d'explorations fonctionnelles pédiatriques, Hôpital d'enfants, CHU de Nancy, France.,EA 3450 DevAH-Laboratoire de Physiologie, Faculté de Médecine, Université Lorraine, Vandoeuvre, France
| | - Silvia Varechova
- Service d'explorations fonctionnelles pédiatriques, Hôpital d'enfants, CHU de Nancy, France.,EA 3450 DevAH-Laboratoire de Physiologie, Faculté de Médecine, Université Lorraine, Vandoeuvre, France
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Brashier B, Salvi S. Measuring lung function using sound waves: role of the forced oscillation technique and impulse oscillometry system. Breathe (Sheff) 2015; 11:57-65. [PMID: 26306104 PMCID: PMC4487383 DOI: 10.1183/20734735.020514] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Measuring lung function is an important component in the decision making process for patients with obstructive airways disease (OAD). Not only does it help in arriving at a specific diagnosis, but it also helps in evaluating severity so that appropriate pharmacotherapy can be instituted, it helps determine prognosis and it helps evaluate response to therapy. Spirometry is currently the most commonly performed lung function test in clinical practice and is considered to be the gold standard diagnostic test for asthma and COPD. However, spirometry is not an easy test to perform because the forceful expiratory and inspiratory manoeuvres require good patient co-operation. Children aged <5 years, elderly people and those with physical and cognitive limitations cannot perform spirometry easily.
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Affiliation(s)
- Bill Brashier
- Chest Research Foundation, Marigold Complex, Kalyaninagar, Pune, India
| | - Sundeep Salvi
- Chest Research Foundation, Marigold Complex, Kalyaninagar, Pune, India
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Lima AN, Faria ACD, Lopes AJ, Jansen JM, Melo PL. Forced oscillations and respiratory system modeling in adults with cystic fibrosis. Biomed Eng Online 2015; 14:11. [PMID: 25889005 PMCID: PMC4334397 DOI: 10.1186/s12938-015-0007-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/28/2015] [Indexed: 11/26/2022] Open
Abstract
Background The Forced Oscillation Technique (FOT) has the potential to increase our knowledge about the biomechanical changes that occur in Cystic Fibrosis (CF). Thus, the aims of this study were to investigate changes in the resistive and reactive properties of the respiratory systems of adults with CF. Methods The study was conducted in a group of 27 adults with CF over 18 years old and a control group of 23 healthy individuals, both of which were assessed by the FOT, plethysmography and spirometry. An equivalent electrical circuit model was also used to quantify biomechanical changes and to gain physiological insight. Results and discussion The CF adults presented an increased total respiratory resistance (p < 0.0001), increased resistance curve slope (p < 0.0006) and reduced dynamic compliance (p < 0.0001). In close agreement with the physiology of CF, the model analysis showed increased peripheral resistance (p < 0.0005) and reduced compliance (p < 0.0004) and inertance (p < 0.005). Significant reasonable to good correlations were observed between the resistive parameters and spirometric and plethysmographic indexes. Similar associations were observed for the reactive parameters. Peripheral resistance, obtained by the model analysis, presented reasonable (R = 0.35) to good (R = 0.64) relationships with plethysmographic parameters. Conclusions The FOT adequately assessed the biomechanical changes associated with CF. The model used provides sensitive indicators of lung function and has the capacity to differentiate between obstructed and non-obstructed airway conditions. The FOT shows great potential for the clinical assessment of respiratory mechanics in adults with CF.
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Affiliation(s)
- Adma N Lima
- Pulmonary Function Laboratory - Faculty of Medical Sciences, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Alvaro C D Faria
- Biomedical Instrumentation Laboratory - Institute of Biology and Faculty of Engineering, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Agnaldo J Lopes
- Pulmonary Function Laboratory - Faculty of Medical Sciences, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - José M Jansen
- Pulmonary Function Laboratory - Faculty of Medical Sciences, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Pedro L Melo
- Biomedical Instrumentation Laboratory - Institute of Biology and Faculty of Engineering, State University of Rio de Janeiro, Rio de Janeiro, Brazil. .,BioVasc Research Laboratory - Institute of Biology, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
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Abstract
COPD is characterized by airflow limitation that is not fully reversible. The morphological basis for airflow obstruction results from a varying combination of obstructive changes in peripheral conducting airways and destructive changes in respiratory bronchioles, alveolar ducts, and alveoli. A reduction of vascularity within the alveolar septa has been reported in emphysema. Typical physiological changes reflect these structural abnormalities. Spirometry documents airflow obstruction when the FEV1/FVC ratio is reduced below the lower limit of normality, although in early disease stages FEV1 and airway conductance are not affected. Current guidelines recommend testing for bronchoreversibility at least once and the postbronchodilator FEV1/FVC be used for COPD diagnosis; the nature of bronchodilator response remains controversial, however. One major functional consequence of altered lung mechanics is lung hyperinflation. FRC may increase as a result of static or dynamic mechanisms, or both. The link between dynamic lung hyperinflation and expiratory flow limitation during tidal breathing has been demonstrated. Hyperinflation may increase the load on inspiratory muscles, with resulting length adaptation of diaphragm. Reduction of exercise tolerance is frequently noted, with compelling evidence that breathlessness and altered lung mechanics play a major role. Lung function measurements have been traditionally used as prognostic indices and to monitor disease progression; FEV1 has been most widely used. An increase in FVC is also considered as proof of bronchodilatation. Decades of work has provided insight into the histological, functional, and biological features of COPD. This has provided a clearer understanding of important pathobiological processes and has provided additional therapeutic options.
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Zannin E, Ventura ML, Dellacà RL, Natile M, Tagliabue P, Perkins EJ, Sourial M, Bhatia R, Dargaville PA, Tingay DG. Optimal mean airway pressure during high-frequency oscillatory ventilation determined by measurement of respiratory system reactance. Pediatr Res 2014; 75:493-9. [PMID: 24375086 DOI: 10.1038/pr.2013.251] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 09/24/2013] [Indexed: 11/09/2022]
Abstract
BACKGROUND The aims of the present study were (i) to characterize the relationship between mean airway pressure (PAW) and reactance measured at 5 Hz (reactance of the respiratory system (X RS), forced oscillation technique) and (ii) to compare optimal PAW (P opt) defined by X RS, oxygenation, lung volume (VL), and tidal volume (VT) in preterm lambs receiving high-frequency oscillatory ventilation (HFOV). METHODS Nine 132-d gestation lambs were commenced on HFOV at PAW of 14 cmH2O (P start). PAW was increased stepwise to a maximum pressure (P max) and subsequently sequentially decreased to the closing pressure (Pcl, oxygenation deteriorated) or a minimum of 6 cmH2O, using an oxygenation-based recruitment maneuver. X RS, regional V L (electrical impedance tomography), and V T were measured immediately after (t 0 min) and 2 min after (t 2 min) each PAW decrement. P opt defined by oxygenation, X RS, V L, and V T were determined. RESULTS The PAW-X RS and PAW-VT relationships were dome shaped with a maximum at Pcl+6 cmH2O, the same point as P opt defined by VL. Below Pcl+6 cmH2O, X RS became unstable between t 0 min and t 2 min and was associated with derecruitment in the dependent lung. P opt, as defined by oxygenation, was lower than the P opt defined by X RS, V L, or V T. CONCLUSION X RS has the potential as a bedside tool for optimizing PAW during HFOV.
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Affiliation(s)
- Emanuela Zannin
- Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano University, Milano, Italy
| | - Maria Luisa Ventura
- Neonatology and Neonatal Intensive Care Unit, Fondazione MBBM - Ospedale San Gerardo, Monza, Italy
| | - Raffaele L Dellacà
- Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano University, Milano, Italy
| | - Miria Natile
- Neonatology and Neonatal Intensive Care Unit, Fondazione MBBM - Ospedale San Gerardo, Monza, Italy
| | - Paolo Tagliabue
- Neonatology and Neonatal Intensive Care Unit, Fondazione MBBM - Ospedale San Gerardo, Monza, Italy
| | - Elizabeth J Perkins
- 1] Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia [2] Department of Neonatology, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Magdy Sourial
- Department of Neonatology, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Risha Bhatia
- Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - Peter A Dargaville
- 1] Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia [2] Department of Paediatrics, Royal Hobart Hospital and University of Tasmania, Hobart, Tasmania, Australia [3] Neonatal Respiratory Group, Menzies Research Institute, Hobart, Tasmania, Australia
| | - David G Tingay
- 1] Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia [2] Department of Neonatology, Royal Children's Hospital, Melbourne, Victoria, Australia [3] Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
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Bates JHT, Irvin CG, Farré R, Hantos Z. Oscillation mechanics of the respiratory system. Compr Physiol 2013; 1:1233-72. [PMID: 23733641 DOI: 10.1002/cphy.c100058] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The mechanical impedance of the respiratory system defines the pressure profile required to drive a unit of oscillatory flow into the lungs. Impedance is a function of oscillation frequency, and is measured using the forced oscillation technique. Digital signal processing methods, most notably the Fourier transform, are used to calculate impedance from measured oscillatory pressures and flows. Impedance is a complex function of frequency, having both real and imaginary parts that vary with frequency in ways that can be used empirically to distinguish normal lung function from a variety of different pathologies. The most useful diagnostic information is gained when anatomically based mathematical models are fit to measurements of impedance. The simplest such model consists of a single flow-resistive conduit connecting to a single elastic compartment. Models of greater complexity may have two or more compartments, and provide more accurate fits to impedance measurements over a variety of different frequency ranges. The model that currently enjoys the widest application in studies of animal models of lung disease consists of a single airway serving an alveolar compartment comprising tissue with a constant-phase impedance. This model has been shown to fit very accurately to a wide range of impedance data, yet contains only four free parameters, and as such is highly parsimonious. The measurement of impedance in human patients is also now rapidly gaining acceptance, and promises to provide a more comprehensible assessment of lung function than parameters derived from conventional spirometry.
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Affiliation(s)
- Jason H T Bates
- Vermont Lung Center, University of Vermont College of Medicine, Burlington, Vermont, USA.
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Assessment of Dynamic Mechanical Properties of the Respiratory System During High-Frequency Oscillatory Ventilation*. Crit Care Med 2013; 41:2502-11. [DOI: 10.1097/ccm.0b013e31828cf3ea] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kelly VJ, Sands SA, Harris RS, Venegas JG, Brown NJ, Stuart-Andrews CR, King GG, Thompson BR. Respiratory system reactance is an independent determinant of asthma control. J Appl Physiol (1985) 2013; 115:1360-9. [PMID: 23990243 DOI: 10.1152/japplphysiol.00093.2013] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mechanisms underlying not well-controlled (NWC) asthma remain poorly understood, but accumulating evidence points to peripheral airway dysfunction as a key contributor. The present study tests whether our recently described respiratory system reactance (Xrs) assessment of peripheral airway dysfunction reveals insight into poor asthma control. The aim of this study was to investigate the contribution of Xrs to asthma control. In 22 subjects with asthma, we measured Xrs (forced oscillation technique), spirometry, lung volumes, and ventilation heterogeneity (inert-gas washout), before and after bronchodilator administration. The relationship between Xrs and lung volume during a deflation maneuver yielded two parameters: the volume at which Xrs abruptly decreased (closing volume) and Xrs at this volume (Xrscrit). Lowered (more negative) Xrscrit reflects reduced apparent lung compliance at high lung volumes due, for example, to heterogeneous airway narrowing and unresolved airway closure or near closure above the critical lung volume. Asthma control was assessed via the 6-point Asthma Control Questionnaire (ACQ6). NWC asthma was defined as ACQ6 > 1.0. In 10 NWC and 12 well-controlled subjects, ACQ6 was strongly associated with postbronchodilator (post-BD) Xrscrit (R(2) = 0.43, P < 0.001), independent of all measured variables, and was a strong predictor of NWC asthma (receiver operator characteristic area = 0.94, P < 0.001). By contrast, Xrs measures at lower lung volumes were not associated with ACQ6. Xrscrit itself was significantly associated with measures of gas trapping and ventilation heterogeneity, thus confirming the link between Xrs and airway closure and heterogeneity. Residual airway dysfunction at high lung volumes assessed via Xrscrit is an independent contributor to asthma control.
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Affiliation(s)
- Vanessa J Kelly
- Department of Medicine, Pulmonary and Critical Care Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
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Uchida A, Ito S, Suki B, Matsubara H, Hasegawa Y. Influence of cheek support on respiratory impedance measured by forced oscillation technique. SPRINGERPLUS 2013; 2:342. [PMID: 23961407 PMCID: PMC3733071 DOI: 10.1186/2193-1801-2-342] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Accepted: 07/23/2013] [Indexed: 11/17/2022]
Abstract
The forced oscillation technique (FOT) is a useful tool to assess respiratory resistance and reactance during tidal breathing in patients with respiratory diseases, specifically asthma and chronic obstructive pulmonary disease. Although the FOT has been clinically used, results of respiratory impedance can be affected by various factors such as upper airway artifact. We investigated the effects of cheek support on respiratory resistance and reactance measured by a commercially available FOT equipment MostGraph-01. Respiratory resistance at 20 Hz (R20) with support of the cheeks was significantly higher than those without the cheek support in healthy subjects. Two different cheek support protocols, support of the cheeks by subjects themselves and an operator, were compared in healthy volunteers and patients with respiratory diseases. The cheek support protocols significantly affected respiratory resistance at 5 Hz (R5) and reactance at 5 Hz (X5) in the patient group but not in the healthy subjects. Moreover, for X5, there was a significant interaction between cheek support protocols (by a subject or operator) and groups (healthy or diseased). In conclusion, during impedance measurements using the FOT, application of cheek support either by subjects or the operator is recommended to reduce upper airway artifacts, however, results obtained by two protocols may be different in patients with respiratory diseases. Contribution of the chest wall and position of the arms to the mechanical properties should be carefully considered in physiological studies in which the FOT is attempted.
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Affiliation(s)
- Akemi Uchida
- Department of Biomedical Engineering, Boston University, Boston, MA 02215 USA
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Bhatawadekar SA, Leary D, Chen Y, Ohishi J, Hernandez P, Brown T, McParland C, Maksym GN. A study of artifacts and their removal during forced oscillation of the respiratory system. Ann Biomed Eng 2013; 41:990-1002. [PMID: 23297001 DOI: 10.1007/s10439-012-0735-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 12/22/2012] [Indexed: 11/25/2022]
Abstract
Respiratory impedance measured by the forced oscillation technique (FOT) can be contaminated by artifacts such as coughing, vocalization, swallowing or leaks at the mouthpiece. We present a novel technique to detect these artifacts using multilevel discrete wavelet transforms. FOT was performed with artifacts introduced during separate 60 s recordings at known times in 10 healthy subjects. Brief glottal closures were generated phonetically and confirmed by nasopharyngoscopic imaging of the glottis. Artifacts were detected using Daubechies wavelets by applying a threshold to squared detail coefficients from the wavelet transforms of both pressure and flow signals. Sensitivity and specificity were compared over a range of thresholds for different level squared detail coefficients. Coughs could be identified using 1st level detail (cd1) coefficients of pressure achieving 96% sensitivity and 100% specificity while swallowing could be identified using cd2 thresholds of pressure with 95% sensitivity and 97% specificity. Male vocalizations could be identified using cd1 coefficients with 88% sensitivity and 100% specificity. For leaks at the mouthpiece, cd3 thresholds of flow could identify these events with 98% sensitivity and 99% specificity. Thus, this method provided an accurate, easy, and automated technique for detecting and removing artifacts from measurements of respiratory impedance using FOT.
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Affiliation(s)
- Swati A Bhatawadekar
- School of Biomedical Engineering, Dalhousie University, 5981 University Avenue, PO Box 15000, Halifax, NS, B3H 4R2, Canada.
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