[Selenium supplementation in critically ill patients: pharmacological issues and current evidence]

Area of Science:

• Biochemistry
• Critical Care Medicine
• Nutritional Science

Context:

• Systemic inflammation in critically ill patients often involves oxidative stress.
• Parenteral selenium, particularly sodium selenite, is considered crucial for antioxidant defense in this population.
• Previous clinical trials on selenium supplementation have yielded conflicting results.

Purpose:

• To review the current understanding of intravenous selenium's role in critically ill patients.
• To discuss the pharmacokinetics and clinical effects of selenium supplementation.
• To identify knowledge gaps regarding optimal selenium dosing and timing.

Summary:

• High-dose intravenous selenium may significantly reduce mortality in critically ill patients with systemic inflammation.
• Understanding the pharmacokinetics reveals an initial pro-oxidant effect followed by a sustained antioxidant effect with continuous infusion, suggesting efficacy and safety.
• Short-term intravenous selenite (bolus plus infusion) effectively optimizes serum selenium and antioxidant selenoenzyme activity.

Impact:

• Intravenous selenium shows promise as a therapeutic agent for critically ill patients, potentially improving outcomes.
• Further dose-ranging trials are needed to establish optimal and safe posology before large-scale Phase III trials.
• Investigating the synergistic effects of selenium with other nutrients, like glutamine, may offer enhanced therapeutic benefits.