Predicting Nonrecovery of Muscle Strength in Critically Ill Patients with Intensive Care Unit–Acquired Weakness

BACKGROUND: Individual differences exist in the recovery of muscle strength in critically ill patients with intensive care unit (ICU)-acquired weakness, but the characteristics of patients who do not recover muscle strength are unclear. OBJECTIVE: To elucidate the factors associated with the nonrecovery of muscle strength in patients with ICU-acquired weakness. METHODS: This prospective cohort study involved critically ill patients with ICU-acquired weakness. The patients' outcomes were categorized as recovery (Medical Research Council Sum Score [MRC-SS] ≥48 until hospital discharge or the time of stroke, death, or ICU readmission) or nonrecovery (MRC-SS <48). Separate logistic regression analyses adjusted for age and sex were performed for each candidate factor to identify factors associated with nonrecovery of muscle strength. RESULTS: A total of 111 patients were included in the analysis. Thirty patients were classified as having nonrecovery. Analysis using a logistic regression model showed that septic shock, duration of deep sedation, corticosteroid use, total amount of corticosteroids used, duration of mechanical ventilation, duration of renal replacement therapy, day of first out-of-bed mobilization, initial evaluation of MRC-SS, and length of ICU stay were age- and sex-adjusted predictors of nonrecovery of muscle strength. CONCLUSIONS: Patients with ICU-acquired weakness with the predictors identified in this study may not recover muscle strength. Future multicenter interventional studies should assess not only the timing of rehabilitation but also its intensity and the muscle groups specifically targeted.