Septic shock is a frequent syndrome with a 45% mortality rate despite intensive care unit (ICU) care, where free radicals may play a key role, and a >40% decrease in plasma selenium concentration is observed. Selenium is a trace element with both indirect enzymatic anti-oxidant, and direct oxidant properties. High dose of sodium selenite administration could increase antioxidant cells capacities, and reduce inflammation by a direct paradoxical pro-oxidative effect. We conduct a study to evaluate the effects of selenium treatment in comparison to placebo, in septic shock patients. Efficacy will be evaluated by the weaning time of catecholamines.

Septic shock - an uncontrolled systemic host response to invasive infection -, leading to multiple organ failure, is a public health issue because of its frequency (> 1/1000 inhabitants per year), its cost and its 45% mortality rate, remaining high despite all the improvements made in ICU for the past 20 years. His physiopathology is better understood with increasing data supporting the key role of free radicals, and a more than 40% plasma selenium concentration decrease that maybe associated with increased morbidity and mortality. Meanwhile, for the past 30 years, researches have been conducted on the essential trace element selenium for its requirement for key antioxidant enzymes, through the 21st aa selenocystein, and also for its potentially toxic, pro-oxidant properties. In septic shock, both properties may be useful, antioxidant enzymatic to increase cell defense especially endothelial cells, and direct pro-oxidant action to decrease the genomic response, especially on phagocytic cells.

The objective of this study is to evaluate the effects of a high dose of selenium administration, such as selenite, at pro-oxydant initial dose followed by anti-oxidant dose in severe septic shock patients with documented infection. The initial dose was chosen as the highest dose of selenium, as sodium selenite, estimated without severe adverse effects in healthy people for a one-day ingestion. The patients are randomized to receive either the placebo or the selenite at this high initial dose followed by lower doses on a 9-day period. The efficacy will be evaluated by the weaning time of catecholamines, with a special attention to the 6-month mortality rate as first secondary end point.

Inclusion Criteria:

• Hospitalization in ICU
• Severe documented infection
• Ventilation
• Circulatory failure requiring high dose of catecholamine
• IGS II score >25 at inclusion
• Informed written consent

Exclusion Criteria:

• Pregnancy
• End phase chronic disease
• Limitation of care
• Shock due to an urinary infection without bacteriemia
• Peritonitis related to peritoneal dialysis or trauma
• Preliminary circulatory failure
• Participating to another clinical trial