Critically ill patients are at risk for significant oxidative stress; however, several small analyses have proposed that supplementation with glutamine, with or without antioxidants, may improve survival. Heyland and colleagues from the Canadian Critical Care Trials Group conducted an international, multicenter study to test the hypothesis that 28-day mortality in critically ill adults would be reduced by supplementation with glutamine, with or without antioxidants. Results were published in a recent issue of The New England Journal of Medicine.
There were 1,223 patients randomized to one of four groups. Overall 28-day mortality was 29.8%. Patients who received glutamine had a trend towards worse mortality at 28 days compared to patients who did not receive glutamine (32.4% vs. 27.2%; adjusted odds ratio [AOR], 1.28; 95% confidence interval [CI], 1.00 to 1.64; P=0.05). The combination of glutamine with antioxidants made no significant difference in survival (AOR, 1.09; 95% CI, 0.86 to 1.40; P=0.48). In-hospital mortality and mortality at 6 months were significantly higher among patients who received glutamine; they also had increases in ICU length of stay, length of mechanical ventilation, and overall hospital length of stay. Antioxidant supplementation had no effect on secondary outcomes. The findings from this large, robust randomized study are in opposition to those of previous smaller studies. Read the full Concise Critical Appraisal.