Course of recovery of respiratory muscle strength and its associations with exercise capacity and handgrip strength: A prospective cohort study among survivors of critical illness

Mel Major; Maarten van Egmond; Daniela Dettling-Ihnenfeldt; Stephan Ramaekers; Raoul Engelbert; Marike van der Schaaf

doi:10.1371/journal.pone.0284097

Course of recovery of respiratory muscle strength and its associations with exercise capacity and handgrip strength: A prospective cohort study among survivors of critical illness

PLoS One. 2023 Apr 13;18(4):e0284097. doi: 10.1371/journal.pone.0284097. eCollection 2023.

Authors

Mel Major^{1

2

3

4}, Maarten van Egmond^{1

2

4}, Daniela Dettling-Ihnenfeldt³, Stephan Ramaekers^{2

3}, Raoul Engelbert^{2

3}, Marike van der Schaaf^{2

3

4}

Affiliations

¹ European School of Physiotherapy, Faculty of Health, Amsterdam University of Applied Sciences, Amsterdam, The Netherlands.
² Center of Expertise Urban Vitality, Faculty of Health, Amsterdam University of Applied Sciences, Amsterdam, The Netherlands.
³ Amsterdam UMC, location University of Amsterdam, Rehabilitation Medicine, Amsterdam, The Netherlands.
⁴ Amsterdam Movement Sciences, Ageing and Vitality, Amsterdam, The Netherlands.

Abstract

Background: Mechanical ventilation affects the respiratory muscles, but little is known about long-term recovery of respiratory muscle weakness (RMW) and potential associations with physical functioning in survivors of critical illness. The aim of this study was to investigate the course of recovery of RMW and its association with functional outcomes in patients who received mechanical ventilation.

Methods: We conducted a prospective cohort study with 6-month follow-up among survivors of critical illness who received ≥ 48 hours of invasive mechanical ventilation. Primary outcomes, measured at 3 timepoints, were maximal inspiratory and expiratory pressures (MIP/MEP). Secondary outcomes were functional exercise capacity (FEC) and handgrip strength (HGS). Longitudinal changes in outcomes and potential associations between MIP/MEP, predictor variables, and secondary outcomes were investigated through linear mixed model analysis.

Results: A total of 59 participants (male: 64%, median age [IQR]: 62 [53-66]) were included in this study with a median (IQR) ICU and hospital length of stay of 11 (8-21) and 35 (21-52) days respectively. While all measures were well below predicted values at hospital discharge (MIP: 68.4%, MEP 76.0%, HGS 73.3% of predicted and FEC 54.8 steps/2m), significant 6-month recovery was seen for all outcomes. Multivariate analyses showed longitudinal associations between older age and decreased MIP and FEC, and longer hospital length of stay and decreased MIP and HGS outcomes. In crude models, significant, longitudinal associations were found between MIP/MEP and FEC and HGS outcomes. While these associations remained in most adjusted models, an interaction effect was observed for sex.

Conclusion: RMW was observed directly after hospital discharge while 6-month recovery to predicted values was noted for all outcomes. Longitudinal associations were found between MIP and MEP and more commonly used measures for physical functioning, highlighting the need for continued assessment of respiratory muscle strength in deconditioned patients who are discharged from ICU. The potential of targeted training extending beyond ICU and hospital discharge should be further explored.

Copyright: © 2023 Major et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Critical Illness*
Exercise Tolerance
Hand Strength* / physiology
Humans
Infant
Male
Muscle Strength / physiology
Muscle Weakness
Prospective Studies
Respiratory Muscles
Survivors

Associated data

figshare/10.21943/auas.20798332

Grants and funding

MM received a research grant by the Dutch Research Council (NWO, 023.007.006). The funder had no role in study design, data collection and analysis, decision to publish or preparation of this manuscript. Part of this research project was funded by Taskforce for Applied Research (SIA, RAAK.PUB04.037). This funder also did not have a role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.