Controversies in Critical Care Nutrition Support.

Critical illness predisposes individuals to highly variable metabolic and immune responses, leading to muscle mass loss, impaired healing, immobility, and susceptibility to infections and cognitive impairment. Recommendations for nutrition in critically ill patients are supported by observational studies, small randomized controlled trials, and mechanistic data. There is no standardization of nutritional therapy in critically ill patients and controversies in the type, quantity, and timing of nutrition support persist. This article reviews the physiologic basis for nutrition support, the concept of nutritional risk, and various controversies in critical care nutrition support.