Does enteral glutamine supplementation decrease infectious morbidity?

BACKGROUND: Although some studies have demonstrated lower infectious morbidity in patients receiving supplemental glutamine, there remains no consensus on the utility of such treatment. This study was designed to investigate the effects of supplemental enteral glutamine on the rate and outcomes of infection in critically ill surgical patients. METHODS: All 185 surgical and trauma patients admitted to a single university surgical trauma intensive care unit (STICU) over an approximately three-year period who were to receive enteral nutrition support were assigned sequentially to one of three diets: standard 1-kCal/mL feedings with added protein (Group 1), standard feedings with glutamine 0.6 g/kg per day (Group 2), or immune-modulated feedings with a similar amount of glutamine (Group 3). Group compositions and patient characteristics were similar at baseline. Data were collected prospectively on infections acquired during hospitalization. RESULTS: A total of 119 patients had at least one infection: 59% of the patients in Group 1, 64% of Group 2, and 69% of Group 3 (p = NS). There were no differences among the groups in the mean number of infections. The most common sites in all groups were the lungs, blood, and urine; and the frequencies of these infections did not differ between groups. Minor differences were found between groups in the organisms isolated. Antibiotic usage did not differ. CONCLUSION: Supplemental enteral glutamine in the dose studied does not appear to influence the acquisition or characteristics of infection in patients admitted to a mixed STICU.

Does the addition of glutamine to enteral feeds affect patient mortality?

OBJECTIVE: Studies have failed to consistently demonstrate improved survival in intensive care unit (ICU) patients receiving immune-modulating nutrient-enhanced enteral feeds when compared with standard enteral feeds. The objective was to study in a prospective fashion the effects of adding glutamine to standard or immune-modulated (supplemented with omega-3 fatty acids, beta-carotene, and amino acids such as glutamine and arginine) tube feeds. DESIGN: Prospective, unblinded study using sequential allocation. SETTING: A university surgical trauma ICU. PATIENTS: All surgical and trauma patients admitted to the surgical trauma ICU at a university hospital over a 3-yr period who were to receive enteral feeds (n = 185). INTERVENTIONS: Sequential assignment to three isocaloric, isonitrogenous diets was performed as follows: standard 1-kcal/mL feeds with added protein (group 1), standard feeds with the addition of 20-40 g/day (0.6 g/kg/day) glutamine (group 2), or an immune-modulated formula with similar addition of glutamine (group 3). The goal for all patients was 25-30 kcal/kg/day and 2 g/kg/day protein. MEASUREMENTS AND MAIN RESULTS: Patients were followed until discharge from the hospital. The primary end point was in-hospital mortality, and multiple secondary end points were recorded. In-hospital mortality for group 1 was 6.3% (four of 64) vs. 16.9% (ten of 59, p = .09) for group 2 and 16.1% (ten of 62, p = .09) for group 3. After controlling for age and severity of illness, the difference in mortality between patients receiving standard tube feeds and all patients receiving glutamine was not significant (p < or = .11). There were no statistically significant differences between the groups for secondary end points. CONCLUSIONS: The addition of glutamine to standard enteral feeds or to an immunomodulatory formula did not improve outcomes. These findings suggest that enteral glutamine should not be routinely administered to patients with surgical critical illness.