Infection, multiple organ failure, and survival in the intensive care unit: influence of glutamine-supplemented parenteral nutrition on acquired infection

Abstract

Objective: We investigated the effect of a glutamine-supplemented parenteral nutrition on intensive-care-acquired infection (ICAI) and its relation to outcome.

Methods: We analyzed new data prospectively collected during a double-blind, randomized, and controlled trial in an adult general intensive care unit previously reported (Nutrition 1997;13:295). Eighty-four patients were randomized to receive glutamine-supplemented total parenteral nutrition or an isonitrogenous, isoenergetic control. Sepsis was present on admission in 71% of the patients. Clinical and microbiological data were collected on all new infective episodes and associated treatment decisions. Data were analyzed blind to the randomization and study outcome.

Results: There was no significant difference in the number of patients developing new infections or in the number occurring during the first 5 d. There was a non-significant trend to increased numbers of infections in those patients receiving the control feed for at least 5 d. In these patients the glutamine recipients showed significantly fewer catheter-related infections: 21 versus 12 (P = 0.026). The difference in overall 6-mo mortality was almost completely described by those patients fed for at least 5 d: 9 of 25 versus 18 of 27 using the control nutrition (P = 0.05). Of the deaths in the intensive care unit due to multiple organ failure, 8 of 8 in the glutamine group and 14 of 16 in the control group sustained one or more ICAI and accounted for 38% versus 74%, respectively, of the ICAIs occurring in those patients. In those patients, despite a similar high incidence of colonization with Candida, those receiving glutamine developed fewer Candida infections and none died, whereas six control patients who developed Candida infections died from multiple organ failure (P = 0.02). Survival was not related to the reduced occurrence of the first acquired infection; however, binary logistic regression analysis of glutamine and the incidence of ICAI after starting total parenteral nutrition to outcome showed that only glutamine was significantly associated with improved 6-mo survival (P = 0.027).

Conclusions: In these severely ill patients, parenteral nutrition containing glutamine may not reduce the overall incidence of ICAI, but it may reduce the risk of dying from acquired infections. The improved survival seen at 6 mo appeared related mostly to reduced mortality in the intensive care unit from multiple organ failure in those patients in whom acquired infections are common.