Severe sepsis is a disease with a high mortality. Development of shock is a most serious complication and increases the risk of death considerably. Application of low dose hydrocortisone is currently recommended only in patients after severe septic shock has been established. Hydrocortisone therapy has a hemodynamic stabilizing effect and may reverse shock, however, the preventive application has not been investigated in a larger study. The study investigates whether low dose hydrocortisone prevents the development of shock in patients with severe sepsis. It is postulated that shock prevention may also affect morbidity and mortality.