Feeding critically ill patients: what a trial of gut vs vein nutrition found
When critically ill adults needed nutrition support, feeding through the gut versus intravenously produced similar mortality, shifting the question from which route is lifesaving to which is safer and when.
What the study found
The CALORIES trial (New England Journal of Medicine, 2014) randomly assigned more than 2,000 critically ill adults to early nutrition delivered through the gut (enteral, via a feeding tube) or through a vein (parenteral). Thirty-day mortality was similar between the two routes; the intravenous route was not superior, and the rates of some complications differed between the groups.
Why it matters
Critically ill patients often cannot eat, and how to feed them — through the gut or the vein — has been debated for decades. Enteral feeding is generally preferred when the gut works, but many patients have gut problems that make it hard. A large head-to-head trial helps ground that choice in evidence rather than tradition.
Analysis — the pattern we're watching
Reading nutrition trials together, a pattern appears (this is analysis, not a fixed rule): in critical illness, more or more-aggressive feeding has repeatedly failed to beat a more measured approach, and the route seems to matter less for survival than avoiding the harms of overfeeding and line complications. Related trials on the timing and amount of intravenous nutrition point the same way. An open, actively studied direction is personalizing nutrition to the patient and the phase of illness rather than applying one target to everyone.
What is still uncertain
These trials study broad ICU populations. Patients with specific problems — short bowel, intestinal failure, or recovery after major gastrointestinal surgery — can differ, and this trial does not settle those cases. The best timing, amount, and composition of nutrition support remain active research questions.