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Lookup NU author(s): Dr Nicholas Lane, Professor Stephen BourkeORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Copyright © 2021 The Authors. We previously showed that use of portable noninvasive ventilation (pNIV) during recovery periods within intermittent exercise improved breathlessness and exercise tolerance in patients with COPD compared with pursed-lip breathing (PLB). However, in a minority of patients recovery from dynamic hyperinflation (DH) was better with PLB, based on inspiratory capacity. We further explored this using Optoelectronic Plethysmography to assess total and compartmental thoracoabdominal volumes. Fourteen patients with COPD (means ± SD) (FEV1: 55% ± 22% predicted) underwent, in a balanced order sequence, two intermittent exercise protocols on the cycle ergometer consisting of five repeated 2-min exercise bouts at 80% peak capacity, separated by 2-min recovery periods, with application of pNIV or PLB in the 5 min of recovery. Our findings identified seven patients showing recovery in DH with pNIV (DH responders) whereas seven showed similar or better recovery in DH with PLB. When pNIV was applied, DH responders compared with DH nonresponders exhibited greater tidal volume (by 0.8 ± 0.3 L, P = 0.015), inspiratory flow rate (by 0.6 ± 0.5 L/s, P = 0.049), prolonged expiratory time (by 0.6 ± 0.5 s, P = 0.006), and duty cycle (by 0.7 ± 0.6 s, P = 0.007). DH responders showed a reduction in end-expiratory thoracoabdominal DH (by 265 ± 633 mL) predominantly driven by reduction in the abdominal compartment (by 210 ± 494 mL); this effectively offset end-inspiratory rib-cage DH. Compared with DH nonresponders, DH responders had significantly greater body mass index (BMI) by 8.4 ± 3.2 kg/m2, P = 0.022 and tended toward less severe resting hyperinflation by 0.3 ± 0.3 L. Patients with COPD who mitigate end-expiratory rib-cage DH by expiratory abdominal muscle recruitment benefit from pNIV application.
Author(s): Chynkiamis N, Lane ND, Megaritis D, Manifield J, Loizou I, Alexiou C, Riazati S, LoMauro A, Bourke SC, Vogiatzis I
Publication type: Article
Publication status: Published
Journal: Journal of Applied Physiology
Year: 2021
Volume: 131
Issue: 1
Pages: 401-413
Print publication date: 01/07/2021
Online publication date: 18/07/2021
Acceptance date: 03/06/2021
Date deposited: 12/08/2021
ISSN (print): 8750-7587
ISSN (electronic): 1522-1601
Publisher: American Physiological Society
URL: https://doi.org/10.1152/japplphysiol.00081.2021
DOI: 10.1152/japplphysiol.00081.2021
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