Longitudinal variation in muscle strength and mobility in patients in an intensive care unit: a retrospective cohort study

OBJECTIVE: To longitudinally evaluate muscle strength and mobility in an intensive care unit and identify factors associated with muscle weakness at intensive care unit discharge. METHODS: A retrospective cohort study was conducted with patients who had their muscle strength measured at some point during their intensive care unit stay. Muscle strength was assessed using the Medical Research Council score, and measurements were taken at two points: as soon as medically possible (first assessment) and discharge. Mobility was assessed using the Functional Status Score for the intensive care unit scale, which includes bed transfer and locomotion activities. These activities were evaluated at three points: previous status, as soon as medically possible (first assessment), and discharge. RESULTS: The change in muscle strength in the sample of 1,310 patients between the assessment at discharge [56 (48 - 60)] and the first assessment [54 (48 - 60)] was significant (p value < 0.001). When comparing mobility levels, a significant difference (p < 0.001) was observed between the time prior to hospitalization [35 (34 - 35)], the first assessment [28 (20 - 33)], and discharge [29 (21 - 35)]. Factors associated with muscle weakness were length of stay in the intensive care unit [OR 1.16 (1.06 - 1.28); p = 0.002]; use of sedation [OR 3.8 (1.27 - 11.16); p = 0.016] and muscle strength score at the first assessment [OR 0.84 (0.79 - 0.90); p = 0.001]. CONCLUSION: Muscle strength and mobility increased from the first assessment to discharge. Prospective studies are needed to explore the trends observed in this study.