The effect of protein provision and exercise therapy on patient-reported and clinical outcomes in intensive care unit survivors: A systematic review

Background: Intensive care unit (ICU) survivors deal with long-term health problems, which negatively affect their quality of life (QoL). Nutritional and exercise intervention could prevent the decline of muscle mass and physical functioning which occurs during critical illness. Despite the growing amount of research, robust evidence is lacking. Methods: For this systematic review, Embase, PubMed and Cochrane Central Register of Controlled Trials databases were searched. The effect of protein provision (PP) or combined protein and exercise therapy (CPE) during or after ICU admission on QoL, physical functioning, muscle health, protein/energy intake and mortality was assessed compared to standard care. Results: Four thousand nine hundred and fifty-seven records were identified. After screening, data were extracted for 15 articles (9 randomised controlled trials and 6 non-randomised studies). Two studies reported improvements in muscle mass, of which one found higher independency in activities of daily living. No significant effect was found on QoL. Overall, protein targets were seldom met and often below recommendations. Conclusion: Evidence for the effect of PP or CPE on patient-reported outcomes in ICU survivors is limited due to study heterogeneity and lack of high-quality studies. Future research and clinical practice should focus on adequate protein delivery with exercise interventions to improve long-term outcomes.