The Effect of Intravenous Selenium on Oxidative Stress in Critically Ill Patients with Acute Respiratory Distress Syndrome

Objective: To modulate the inflammatory response in respiratory distress syndrome (ARDS) with selenium.

Background: Selenium replenishes the glutathione peroxidase proteins that are the first line of defense for an oxidative injury to the lungs.

Methods: Forty patients with ARDS were randomized into two groups: the SEL⁺ group being administered sodium selenite and the SEL^– group receiving normal saline for 10 days. Blood samples were taken on Day-0, DAY-7, and Day-14 for assessment of IL-1 beta, IL-6, C-reactive protein, GPx-3, and selenium. Ferric reducing antioxidant power (FRAP) was measured in the bronchial wash fluids. Pearson correlation and repeated measure analysis were performed to examine the effects of selenium on the inflammatory markers.

Results: Sodium selenite replenished selenium levels in the SEL⁺ group. Selenium concentrations were linearly correlated to serum concentrations of GPx3 (R value: 0.631; P < 0.001), and FRAP (R value: ?0.785; P < 0.001). Serum concentrations of both IL 1-beta (R value: ?0.624; P < 0.001) and IL-6 (R value: ?0.642; P < 0.001) were inversely correlated to the serum concentrations of selenium. There was a meaningful difference between two groups in airway resistance and pulmonary compliance changes (P values 0.008 and 0.028, respectively).

Conclusion: Selenium restored the antioxidant capacity of the lungs, moderated the inflammatory responses, and meaningfully improved the respiratory mechanics. Despite these changes, it had no effect on the overall survival, the duration of mechanical ventilation, and ICU stay. Selenium can be used safely; however, more trials are essential to examine its clinical effectiveness.