Nutrition support in the ICU: current evidence and evolving standards

Area of Science:

• Critical care medicine
• Clinical nutrition
• Metabolic research

Background:

• Nutritional support is vital for critically ill patients.
• Metabolic changes in critical illness cause muscle wasting.
• Traditional early full nutrition may cause harm.

Purpose of the Study:

• To review current evidence on macronutrient delivery in critical illness.
• To discuss optimal nutrition strategies during acute and recovery phases.
• To highlight the need for individualized and phase-specific nutritional support.

Main Methods:

• Review of recent large randomized trials.
• Analysis of observational studies on nutritional intake.
• Synthesis of current evidence and clinical recommendations.

Main Results:

• Early full nutritional replacement may cause harm (overfeeding, refeeding syndrome).
• Low-calorie, low-protein strategies in the acute phase may improve outcomes.
• Protein delivery has not consistently improved survival and may harm patients with acute kidney injury.
• Inadequate nutrition is common in the recovery phase.

Conclusions:

• A cautious, individualized approach avoiding overfeeding is recommended for the acute phase.
• Low-calorie, low-protein feeding strategies warrant consideration.
• Further research is needed to define optimal nutrition in the recovery phase for long-term outcomes.