Nutrition and infection in the intensive care unit: what does the evidence show?

Nutrition support when applied appropriately, can improve clinical outcomes, particularly the incidence of infections. The Canadian Clinical Practice Guidelines for Nutrition Support, published in October 2003, summarized the evidence on nutrition support in the critically ill patient and provided recommendations aimed at maximizing the benefits of nutrition support while minimizing the risks. The purpose of this review is to highlight recent advances in nutrition research in critically ill adult patients, particularly with respect to minimizing infection. The newly published data will be used to update the Canadian Clinical Practice Guidelines.

Recent studies have confirmed that the use of enteral nutrition versus parenteral nutrition, early initiation of enteral nutrition, use of enteral and parenteral glutamine and intensive insulin therapy are all associated with reduced infectious morbidity in critically ill patients. A recent meta-analysis suggests that antioxidant supplementation is associated with no improvement in infectious complications, but an increase in survival. The recommendations from the Canadian Clinical Practice Guidelines for Nutrition Support have been updated based on the data from these recent trials.

This review provides insights into the results of recent randomized trials on nutrition support in critically ill patients. The Canadian Clinical Practice Guidelines for nutrition support help intensive care unit clinicians to keep abreast of emerging evidence and the impact of nutrition support practices on outcomes such as infections.