Glutamine, antioxidants not useful in critically ill patients, study shows

For critically ill adults with multiorgan failure, early supplementation with glutamine or antioxidants does not improve clinical outcomes, and glutamine may increase the mortality rate of this patient population, according to a study published in the April 18 issue of the New England Journal of Medicine.

Canadian researchers wanted to evaluate the use of early glutamine and antioxidant supplementation in critically ill patients to determine if it would positively affect 28-day mortality. In a large, double-blinded, multicentered randomized trial with intention-to-treat analysis, they randomly assigned more than 1,200 critically ill patients in 40 intensive care units (ICUs) in Canada, the United States, and Europe to receive supplements of glutamine, antioxidants, both, or placebo. Patients had multiorgan failure and were receiving mechanical ventilation. Supplementation, provided both intravenously and enterally, began within 24 hours of ICU admission. Primary outcome was 28-day mortality.

Study lead author Daren Heyland MD, MSc, scientific director, clinical evaluation research unit, Kingston General Hospital,
Kingston, Ontario, Canada, and colleagues found that a higher percentage of patients who received glutamine died within the 28-day period (32.4% vs 27.2%; adjusted odds ratio [OR], 1.28; P=0.05). Also, mortality at 6 months was significantly higher among those patients who received glutamine than among those who didn’t. The rates of organ failure and infectious complications were not affected by glutamine. Antioxidant supplementation did not affect 28-day mortality (30.8%, vs 28.8% with no antioxidants; adjusted OR, 1.09; 95% CI, 0.86–1.40; P=.48) or on the secondary end points of inhospital mortality and mortality at 6 months. The groups did not differ with respect to serious adverse events (P=.83).

“The most important finding from the study is the glutamine supplementation in this patient population-critically ill patients with multiorgan failure-was harmful. In addition, antioxidant supplementation did not seem to be beneficial or harmful,” said Dr. Heyland. “Glutamine supplementation should not be offered to such patients.”