NUTRITION AND THE INTENSIVE CARE UNIT: Edited by Peter J.M. Weijs and Stephen A. McClaveMuscle weakness and nutrition therapy in ICUCasaer, Michael P.Author Information Clinical Department and Laboratory of Intensive Care Medicine, Division of Cellular and Molecular Medicine, Katholieke Universiteit Leuven, Leuven, Belgium Correspondence to Michael P. Casaer, Department of Intensive Care Medicine, University Hospitals Leuven (UZLeuven), Herestraat 49, B-3000 Leuven, Belgium. Tel: +32 16 344017; fax: +32 16 344015; e-mail: [email protected] Current Opinion in Clinical Nutrition and Metabolic Care: March 2015 - Volume 18 - Issue 2 - p 162-168 doi: 10.1097/MCO.0000000000000150 Buy Metrics Abstract Purpose of review Muscle wasting is common in severe critical illness. ICU-acquired weakness (ICU-AW) contributes to acute and long-term morbidity and mortality. The question remains whether nutrition therapy in ICU can prevent or attenuate these complications. This review aims at integrating the most recent clinical data in order to answer this important clinical and research question. Clinical evidence was obtained from randomized controlled trials (RCTs). Results from animal experiments and observational studies are referred to when – respectively – providing possible explanatory mechanisms or new hypotheses. Recent findings Although muscle wasting has been reproducibly quantified early in ICU, its relationship with ICU-AW has not yet been convincingly established. All recent RCTs evaluating increased energy/protein intake during ICU week 1 failed to demonstrate a protective effect against ICU-AW or physical function limitations. In one RCT, early parenteral nutrition increased the incidence of ICU-AW. The latter finding might be explained by suppressed autophagy. Summary Current evidence does not support improved physical function with increased energy/protein provision in the first ICU week. Future RCTs aimed at reducing the burden of ICU-AW and improving long-term function should particularly focus on nutrition beyond the acute phase of critical illness and on non-nutritional interventions such as early mobilization. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.