Inspiratory muscle strength and function in mechanically ventilated COVID-19 survivors 3 and 6 months after intensive care unit discharge.

Abstract

BackgroundKnowledge regarding the long-term impact of invasive mechanical ventilation on the inspiratory muscles and functional outcomes in COVID-19 survivors is limited.MethodsIn this single-centre prospective cohort study, we evaluated invasively ventilated patients with COVID-19 pneumonia 3 and 6 months post -ICU discharge. Outcomes included: maximal inspiratory pressure (MIP), ultrasound parameters for diaphragm function, 6-min walk distance (6MWD), dyspnea and quality of life. We evaluated associations between MIP and duration of mechanical ventilation with follow-up outcomes.ResultsFifty COVID-19 survivors discharged from ICU between 15 Oct 2020 and 1 Apr 2021 were enrolled. Overall, survivors showed a recovery trajectory over time. However, impaired MIP remained in 24(48%) and 12 (24%) at 3 and 6 months, respectively. Diaphragm dysfunction was not observed. At 3 months, 23 (46%) had impaired functional capacity versus 10 (20%), at 6 months. Dyspnea persisted in 44 (88%) at 3 months and 38 (76%) at 6 months. Quality of life was slightly decreased at 3 months with further improvements at 6 months. MIP was correlated to 6MWD, 6MWD % predicted, dyspnea across follow-up and quality of life at 3 months. The duration of invasive ventilation was correlated with 6MWD and 6MWD % predicted.ConclusionIn invasively ventilated COVID-19 survivors, inspiratory muscle strength impairments persisted 6 months after ICU discharge, while maintaining normal diaphragm function. Decreased functional capacity, dyspnea and slightly reduced health status were observed. Early screening of survivors is of utmost importance to identify those with impairments and at risk of delayed or incomplete recovery.