Original Research ARTICLE
PLETHYSMOGRAPHIC LOOPS: A WINDOW ON THE LUNG PATHOPHYSIOLOGY OF COPD PATIENTS
- 1Dipartimento di Scienze Biomediche e Cliniche "L. Sacco", Università degli Studi di Milano, Italy
- 2Dipartimento di Fisiopatologia e dei Trapianti, Università degli Studi di Milano, Italy
Plethysmographic alveolar pressure-flow (Palv–F) loops contain potentially relevant information about the pathophysiology of chronic obstructive pulmonary disease (COPD), but no quantitative analysis of these loops during spontaneous breathing has ever been performed.
The area of the loop’s inspiratory (Ains) and expiratory portion (Aexp), and the difference between the end-expiratory and end-inspiratory alveolar pressure (ΔPalv) were measured in 20 young, 20 elderly healthy subjects, and 130 stable COPD patients.
Ains and ΔPalv increased by 55 and 78% from young to elderly subjects, and by 107 and 122% from elderly subjects to COPD patients, reflecting changes in mechanical heterogeneity, lung-units recruitment/derecruitment, and possibly air trapping occurring with aging and/or obstructive disease. Aexp increased by 38% from young to elderly subjects, and by 198% from elderly subjects to COPD patients, consistent with the additional contribution of tidal expiratory flow-limitation, which occurs only in COPD patients and affects Aexp only. In COPD patients, Aexp and ΔPalv showed a significant negative correlation with VC, FEV1, IC, and a significant positive correlation with RV/TLC.
The results suggest that the analysis of plethysmographic Palv–F loops provides an insight of the pathophysiological factors, especially tidal expiratory flow-limitation, that affect lung function in COPD patients
Keywords: plethysmographic loops, Airway Resistance, chronic obstructive pulmonary disease, Respiratory Function Tests, Respiratory pathophysiology
Received: 14 Feb 2018;
Accepted: 16 Apr 2018.
Edited by:Yu Ru Kou, National Yang-Ming University, Taiwan
Reviewed by:Bela Suki, Boston University, United States
NIckolaos G. Koulouris, National & Kapodistrian University of Athens
Copyright: © 2018 Radovanovic, Pecchiari, Pirracchio, Zilianti, D'Angelo and Santus. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: MD, PhD. Matteo M. Pecchiari, Università degli Studi di Milano, Dipartimento di Fisiopatologia e dei Trapianti, Milan, 20133, Italy, firstname.lastname@example.org