Central Venous Oxygen Saturation above 75% on Day Three of Septic Shock is Associated with Tripled Mortality

Abstract

Background: Central venous oxygen saturation (ScvO2) is commonly used to identify global oxygen uptakedelivery mismatches. A level above 70% was the declared goal in early resuscitation of septic shock for over a decade. Recent evidence leads to doubts and levels higher than 80% may represent harmful conditions. This study ´s aim was to identify favourable ScvO2 levels in treatment of septic shock. Methods: Electronic data of patients suffering from septic shock who have been admitted to the surgical intensive care unit of a university hospital were analysed surveying a period of six years with focus on the association of ScvO2 levels with in-hospital mortality. Results: Data from 238 individuals were included. No difference was found comparing initially measured values of ScvO2 of survivors to non-survivors. Patients whose levels of ScvO2 never exceeded 70% (n=28) had a higher mortality rate (73.2% vs. 54.3%, p<0.05). On day three patients with values above 75% (n=32) had higher mortality rates (59.4% vs. 38.5%, p<0.05). A mortality rate of 100% was detected if ScvO2 levels exceeded 84% (n=6). Conclusions: ScvO2 develops from a therapy guiding parameter to a prognostic marker. Reaching levels of at least 70% within the first 72 h of disease is favourable in regard to prognosis. Exceeding 75% after day two is associated with higher mortality. These findings require further confirmation. At this point it can be assumed that a varying, time-dependent ScvO2 approach might be required for clinical decision-making.