[Selenium in critically ill patients with systemic inflammatory response].

Selenium is an essential micronutrient for humans. Critically ill patients with Systemic Inflammatory Response Syndrome (SIRS) and Multiple Organ Dysfunction (MOD) -such as severe sepsis, trauma, severe pancreatitis and critical burns- are exposed to severe oxidative stress. These patients exhibit decreased serum Selenium and selenoenzymes like Glutathione Peroxidase and Selenoprotein P. Selenoenzymes play a major role in protecting cells against lipid peroxidation and they are involved in the inflammatory response regulation. The degree of selenium deficiency correlates with disease severity and the incidence of mortality. In the past years, some clinical trials have studied Selenium supplementation effects in critical illness with SIRS-MOD. This therapeutic strategy could improve the outcome and prognosis in critically ill patients. Few small trials have demonstrated Selenium supplementation beneficial effects, reducing the rate of infectious complications and length of hospital stay. However, no clinical trials using Selenium supplementation in high doses have yet demonstrated significant improvement in mortality. The aims of this review are to evaluate: a) Selenium metabolism, b) the role of selenoenzymes during critical illness, c) clinical studies using Selenium alone or in combination with other antioxidants in critically ill patients and d) to analyze current parenteral Selenium replacement strategies and their results. Further multicentre, well designed randomized, double blind clinical trials about Selenium supplementation in critically ill patients with SIRS and MODS are required and appear to be attractive, necessary and challenging.