The role of total parenteral nutrition in critical illness: guidelines and recommendations.

Critically ill patients experience a multitude of metabolic derangements in response to sepsis, shock, and severe injury. The result of extreme stress is characterized by alterations in carbohydrate and fat metabolism and persistent catabolism of lean body mass. Total parenteral nutrition is an important therapeutic modality in the care of critically ill patients. In this article, the author identifies the patient at risk, defines the appropriate time to initiate parenteral nutrition, and outlines current recommendations for energy and protein prescription. The author also briefly reviews administration issues, discusses possible complications of therapy, and defines effective strategies to monitor the response to therapy.