Nutrition in the critically ill patient

To summarize recent relevant studies regarding nutrition during critical illness and provide recommendations for clinical practice.

Recently acquired knowledge regarding nutritional status and risk assessment, body composition, gastric residual volume, prokinetics, tube positioning, enteral vs parenteral nutrition, nutritional dose and timing of initiation, pharmaconutrition, dysbiosis and probiotics are discussed.

Body composition especially lean body mass is associated with clinical outcomes. The modified NUTrition Risk in the Critically ill score was validated for nutritional risk assessment and identifies patients that benefit from higher nutritional intake; however, caloric restriction decreases mortality in refeeding syndrome. Gastric residual volume monitoring is debated, as abandoning its application doesn't worsen outcome. There is no consensus regarding benefits of gastric vs postpyloric tube placement. Current prokinetics temporarily reduce feeding intolerance, new prokinetics are developed. Enteral remains preferable over parenteral nutrition, although no inferiority of parenteral nutrition is reported in recent studies. Studies imply no harm of hypocaloric feeding when protein requirements are met. Optimal protein provision may be more important than caloric adequacy. Pharmaconutrition confers no superior outcomes and may even confer harm. Dysbiosis is frequently encountered and associated with worse outcomes. Probiotics reduce infectious complications, but not mortality, and may contribute to earlier recovery of gut function.