Antioxidant supplementation for the treatment of acute lung injury: a meta-analysis.

Objective: This meta-analysis was performed to evaluate the evidence supporting antioxidant supplementation as an adjunct therapy to prevent oxidative damage and improve the clinical outcomes (mortality, length of hospital stay and duration of mechanical ventilation).
Methods: The search strategy for randomized controlled trials (RCTs) involved the participation of two researchers who independently assessed the methodological quality of each full-text article that was available in the PubMed, ISI WEB of Knowledge and ScienceDirect databases.
Results: We extracted 110 studies from the past 10 years, but only 30 articles met the methodological criteria (RCT, blinded and statistically significant results), for a total of 241 animals and 256 patients. This study found an odds ratio (OR) of 0.45 [95% confidence interval (CI): 0.26 to 0.79] for death in the experimental group compared with placebo (six trials, n = 256), an OR of 0.46 [95% CI: 0.26 to 0.87] for hospitalization time and an OR of 0.63 [95% CI: 0.35 to 1.12] for mechanical ventilation time between groups.
Conclusion: Conflicting evidence makes it impossible to recommend the routine use of antioxidant supplementation in critically ill patients.