Nutrition determinants of acute skeletal muscle loss in critically ill patients: A prospective observational cohort study.

Background: Skeletal muscle loss is associated with adverse outcomes in critically ill patients and risk factors of acute skeletal muscle loss are not well described. This study aims to determine the factors associated with acute skeletal muscle loss in critically ill patients.

Methods: This prospective observational cohort study was conducted with patients who were expected to stay in the intensive care unit (ICU) for at least a week. Rectus femoris cross-sectional area (RFCSA) measurements were performed within 48 h of ICU admission and on study day 7. The percentage change in RFCSA and variables associated with this change were evaluated by univariate and multivariate regression analysis.

Results: Over a 12-month period, 518 patients were assessed for eligibility and 44 critically ill patients with a mean age of 59.3 ± 10.9 years were enrolled; 52.3% of them were female. There were significant reductions in RFCSA (16.8 ± 16.5%; P < 0.001). The mean amounts of protein and energy consumed compared with those prescribed were 67.0 ± 28.8% and 71.5 ± 38.3%, respectively. Multivariate regression analysis revealed that frailty was independently associated with acute skeletal muscle loss after adjusting for confounding factors in our cohort of patients.

Conclusion: Frailty status before ICU admission is associated with acute skeletal muscle loss and may be important for identifying critically ill patients at high risk of muscle wasting.