Effectiveness of physical exercise and neuromuscular electrical stimulation interventions for preventing and treating intensive care unit-acquired weakness: A systematic review of randomized controlled trials

Objective: Intensive care unit-acquired weakness is a frequent problem that develops as a secondary disorder while patients are suffering from life-threatening conditions. This study aimed to evaluate the effectiveness of physical exercise or neuromuscular electrical stimulation interventions on (i) preventing loss of muscle mass and weakness in critically ill patients admitted to intensive care units; (ii) recovering patients discharged from the intensive care unit with acquired weakness. Methods: A systematic review of randomized controlled trials was carried out, with studies identified in PubMed, Scopus, and Web of Science. The studies included assessed muscle mass and muscle strength, and performed a time x group analysis of effects. The risk of bias assessment was performed using the Revised Cochrane risk-of -bias tool for randomized trials. Results: Six trials with low risk of bias examined muscle mass, muscle strength, and functionality in 182 adult patients. In critically ill patients admitted to intensive care units, both neuromuscular electrical stimulation and bed/chair cycling for five to ten days prevented significant muscle loss. neuromuscular electrical stimulation in lower and upper limbs resulted in a significant reduction in the length of the hospitalization. In addition, cycle ergometer increased muscle strength and functionality. In patients discharged from the intensive care unit with acquired weakness, both neuromuscular electrical stimulation and physical exercise interventions increased muscle strength, but only physical exercise increased functionality. Conclusions: Physical exercise and neuromuscular electrical stimulation interventions prevent excessive muscle mass loss in critically ill patients admitted to the intensive care unit and increase muscle strength in patients discharged from the intensive care unit with acquired weakness. Physical exercise seems more adequate for improving functionality.