Nutrition Support in Critically Ill Patients

Primary Approach: Enteral Nutrition First

The American Society for Parenteral and Enteral Nutrition recommends attempting enteral nutrition within 48 hours of ICU admission in all hemodynamically stable patients with functioning gastrointestinal tracts, as this reduces infectious complications by 50% compared to early parenteral nutrition (relative risk 0.50, 95% CI 0.37-0.67) 4
Enteral nutrition should be started at low rates (10-20 mL/hour) while carefully monitoring for gastrointestinal intolerance, then increased slowly as tolerated 4
The European Society for Clinical Nutrition and Metabolism recommends targeting approximately 70% of measured energy expenditure during the acute early phase (days 1-2), avoiding full feeding which has been shown to cause harm 5, 6

The European Society for Clinical Nutrition and Metabolism recommends initiating parenteral nutrition if enteral nutrition remains insufficient or not feasible after 3 days, providing approximately 50% of predicted or measured energy needs (not full feeding) 1, 2, 7
This applies specifically to patients with expected ICU stay longer than 3 days and organ failure (SOFA score >4) 2
The American College of Critical Care Medicine recommends continuing or initiating parenteral nutrition if oral/enteral intake remains inadequate after day 7, now targeting full energy requirements 2

The European Society for Clinical Nutrition and Metabolism recommends providing 20-25 kcal/kg/day (approximately 50% of full needs) to avoid overfeeding during the acute phase (days 3-7) 1
Protein intake should start low (<0.8 g/kg/day) early, then progress to 1.3-1.5 g/kg/day as patients stabilize 5
The American Society for Parenteral and Enteral Nutrition recommends increasing to match measured energy expenditure using indirect calorimetry when available during the recovery phase (after day 7) 5, 6
Target protein delivery should be ≥1.2 g/kg/day during the recovery phase 5

Central venous access is required for high osmolarity parenteral nutrition mixtures designed to cover full nutritional needs (>850 mOsmol/L) 2
Peripheral parenteral nutrition can be considered only for low osmolarity solutions (<850 mOsmol/L) providing partial nutrition support 2

In patients with sepsis or septic shock, the European Society for Clinical Nutrition and Metabolism recommends providing 20-50% of nutrition support early, then increasing gradually according to GI tolerance once hemodynamic alterations resolve 1, 7
In post-surgical patients (abdominal/esophageal), the European Society for Clinical Nutrition and Metabolism recommends preferring early enteral nutrition over delayed enteral nutrition when GI tract is intact 1, 7