ICU · Nutrition

ICU nutrition: enteral vs parenteral, timing, protein, and refeeding syndrome

Also known as ICU nutrition · Enteral nutrition · Parenteral nutrition · Early feeding · Refeeding syndrome · Protein targets ICU · Permissive underfeeding · Trophic feeding · EPaNIC trial · PermiT trial · CALORIES trial · NUTRIREA-2

ICU nutrition is early enteral feeding when the gut can be used, protein delivered progressively, and calories held below full target in the first days. CALORIES found no 30-day mortality difference between early PN and early EN started within 36 hours (33.1 versus 34.2 percent). NUTRIREA-2 found no 28-day mortality difference in ventilated shock (37 versus 35 percent) but more digestive complications, including bowel ischaemia, with early isocaloric EN. EPaNIC: late supplemental PN (not before day 8) meant fewer ICU infections (22.8 versus 26.2 percent) and faster recovery than early PN within 48 hours. PermiT: 40 to 60 percent of calculated calories with similar protein was not superior to 70 to 100 percent for 90-day mortality. EDEN: trophic (~400 kcal/day) versus full (~1300 kcal/day) for 6 days did not change ventilator-free days or 60-day mortality. NICE CG32: high refeeding risk starts at a maximum of 10 kcal/kg/day (5 kcal/kg/day if BMI less than 14 or negligible intake over 15 days), with thiamin 200 to 300 mg before and during the first 10 days.

Checked against its sources on 2 Sept 2026