Enteral Nutrition in the ICU and Wards: Review

Underfeeding and overfeeding each pose risks, depending on the patient

Nutrition is complex, and so it should not be surprising that the data on nutritional support in hospitalized patients represent something of a paradox.

A relatively robust evidence base suggests strongly that an assertive approach to nutrition can save lives in hospitalized patients who are malnourished or at risk.

However, in the most severely ill patients, the choice of nutritional support and the number of calories delivered have shown no significant effect on outcomes.

After decades of advising intensivists that critically ill patients should receive as many (or more) calories as healthy adults, nutrition experts today acknowledge this is often unnecessary, and may even be harmful.

The change comes in response to mounting randomized trial data over the past 15 years, much of which we’ve reviewed here, demonstrating similar outcomes in critically ill patients who receive fewer calories.

Nutrition research is highly vulnerable to confounding. Observational studies consistently confirm the common-sense finding that patients who are more underweight, with lower muscle mass, who attain lower caloric goals during hospitalization have worse outcomes compared to patients without these factors.

But severe illness is also associated with all these adverse processes. Patients lose appetite, gut motility, and anabolic capacity during life-threatening (or life-ending) illness. Thus, randomized trials are required to discover whether attempts at countering catabolism with increased nutrition delivery can improve outcomes.

In critically ill patients, these trials have generally not shown benefit. But the persistent belief that optimized delivery of nutrition can improve outcomes does have some basis in evidence.

Nutrition Support Can Save Lives