Lung volume recruitment acutely increases respiratory system compliance in individuals with severe respiratory muscle weakness

Yannick Molgat-Seon; Liam M Hannan; Paolo B Dominelli; Carli M Peters; Renee J Fougere; Douglas A McKim; A William Sheel; Jeremy D Road

doi:10.1183/23120541.00135-2016

Lung volume recruitment acutely increases respiratory system compliance in individuals with severe respiratory muscle weakness

ERJ Open Res. 2017 Mar 14;3(1):00135-2016. doi: 10.1183/23120541.00135-2016. eCollection 2017 Jan.

Authors

Yannick Molgat-Seon¹, Liam M Hannan², Paolo B Dominelli¹, Carli M Peters¹, Renee J Fougere³, Douglas A McKim⁴, A William Sheel¹, Jeremy D Road⁵

Affiliations

¹ School of Kinesiology, University of British Columbia, Vancouver, Canada.
² Institute for Breathing and Sleep, Austin Hospital, Heidelberg, Australia; Faculty of Medicine, Dentistry and Health Science, University of Melbourne, Melbourne, Australia.
³ Faculty of Nursing, University of Toronto, Toronto, Canada; Faculty of Medicine, University of British Columbia, Vancouver, Canada.
⁴ Division of Respiratory Medicine, The Ottawa Hospital, Ottawa, Canada; Ottawa Hospital Research Institute, Ottawa, Canada.
⁵ Faculty of Medicine, University of British Columbia, Vancouver, Canada; Division of Respiratory Medicine, Vancouver General Hospital, Vancouver, Canada.

Abstract

The aim of the present study was to determine whether lung volume recruitment (LVR) acutely increases respiratory system compliance (C_rs) in individuals with severe respiratory muscle weakness (RMW). Individuals with RMW resulting from neuromuscular disease or quadriplegia (n=12) and healthy controls (n=12) underwent pulmonary function testing and the measurement of C_rs at baseline, immediately after, 1 h after and 2 h after a single standardised session of LVR. The LVR session involved 10 consecutive supramaximal lung inflations with a manual resuscitation bag to the highest tolerable mouth pressure or a maximum of 50 cmH₂O. Each LVR inflation was followed by brief breath-hold and a maximal expiration to residual volume. At baseline, individuals with RMW had lower C_rs than controls (37±5 cmH₂O versus 109±10 mL·cmH₂O^-1, p<0.001). Immediately after LVR, C_rs increased by 39.5±9.8% to 50±7 mL·cmH₂O^-1 in individuals with RMW (p<0.05), while no significant change occurred in controls (p=0.23). At 1 h and 2 h post-treatment, there were no within-group differences in C_rs compared to baseline (all p>0.05). LVR had no significant effect on measures of pulmonary function at any time point in either group (all p>0.05). During inflations, mean arterial pressure decreased significantly relative to baseline by 10.4±2.8 mmHg and 17.3±3.0 mmHg in individuals with RMW and controls, respectively (both p<0.05). LVR acutely increases C_rs in individuals with RMW. However, the high airway pressures during inflations cause reductions in mean arterial pressure that should be considered when applying this technique.