Predictors of Long-term Muscle Weakness in Survivors of Covid-19 Acute Respiratory Distress Syndrome

Abstract

Background Long-term weakness is common in survivors of COVID-19–associated acute respiratory distress syndrome (CARDS). We assessed the predictors of muscle weakness in patients evaluated at 3, 6, and 12 months after intensive care unit discharge with in-person visits. Methods Muscle strength was measured by isometric maximal voluntary contraction (MVC) of the tibialis anterior muscle. Candidate predictors of muscle weakness were follow-up time, sex, age, mechanical ventilation duration, use of steroids in the intensive care unit, compound muscle action potential of the tibialis anterior muscle (CMAP-TA-S100), severe fatigue, depression and anxiety, post-traumatic stress disorder, cognitive assessment, and body mass index. We also compared the clinical tools currently available for the evaluation of muscle strength (handgrip strength, Medical Research Council sum score) and electrical neuromuscular function (simplified peroneal nerve test [PENT]) with more objective and robust measures of force (MVC) and electrophysiological evaluation of the neuromuscular function of the tibialis anterior muscle (CMAP-TA-S100) for its essential role in ankle control. Results MVC improved at 12 months compared with 3 months. Sex (P < 0.001), age (P = 0.012), duration of mechanical ventilation (P = 0.044), and CMAP-TA-S100 (P < 0.001) were independent predictors of MVC. MVC was strongly associated with handgrip strength, whereas CMAP-TA-S100 was strongly associated with PENT. Conclusions Female sex, increasing age, increased duration of mechanical ventilation, and electrical neuromuscular abnormalities are independently associated with reduced MVC and can be used to predict the risk of long-term muscle weakness in CARDS survivors. Trial registration : The present study was registered at ClinicalTrial.gov (NCT: ​​NCT04608994). Registered on October 30, 2020. Retrospectively registered.