<qa>  What is the first secondary end point of the study?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. 