[Exercise capacity after mechanical ventilation because of COVID-19: Cardiopulmonary exercise tests in clinical rehabilitation]

Abstract

Objective: To safely and effectively train the exercise capacity of post-COVID-19 patients it is important to test for cardiopulmonary risk factors and to assess exercise limitations. The goal of this study was to describe the exercise capacity and underlying exercise limitations of mechanically ventilated post-COVID-19 patients in clinical rehabilitation.

Design: A retrospective cohort study.

Method: Twenty-four post-COVID-19patients that were mechanically ventilated at ICU and thereafter admitted for clinical rehabilitation performed a symptom-limited cardiopulmonary exercise test (CPET) with breath-by-breath gas-exchange monitoring, ECG-registration, blood pressure- and saturation monitoring. In absence of a primary cardiac or ventilatory exercise limitation patients were considered to be limited primarily by decreased peripheral muscle mass.

Results: Twenty-three patients could perform a maximal exercise test and no adverse events occurred. Cardiorespiratory fitness was very poor with a median peak oxygen uptake of 15.0 [10.1-21.4] mlO2/kg/min (57% of predicted values). However, we observed large differences within the group in both exercise capacity and exercise limitations. While 7/23 patients were primarily limited by ventilatory function, the majority (70%) was limited primarily by the decreased peripheral muscle mass.

Conclusion: Cardiorespiratory fitness of post-COVID-19 patients in clinical rehabilitation is strongly deteriorated. The majority of patients seemed primarily limited for exercise by the decreased peripheral muscle mass.