Objective: To assess the impact of hemodynamic variables on the outcome of critically ill patients in septic shock and to identify the optimal threshold values related to outcome with special reference to continuously monitored mean arterial pressure (MAP) and mixed venous oxygen saturation (SvO2).
Design and setting: Retrospective cohort study in a university hospital intensive care unit (ICU).
Patients: All consecutive 111 patients with septic shock treated in our ICU between 1 Jan. 1999 and 30 Jan. 2002.
Measurements and results: The data on the hemodynamic and respiratory monitoring and circulation-related laboratory tests over the first 48 h of treatment in the ICU were collected from the clinical data management system. Data from 6 h and 48 h were analyzed separately. The 30-day mortality rate was 33% (36 of 111). Univariate analysis and forward stepwise logistic regression analysis were performed using the 30-day mortality as the primary endpoint. Mean MAP and lactate on arrival during 6 h, while mean MAP, the area of SvO2 under 70%, and mean CVP during 48 h were independently associated with mortality. MAP level of 65 mmHg and SvO2 of 70% had the highest areas under receiver characteristics curves.
Conclusions: MAP, SvO2, CVP, and initial lactate were independently associated with mortality in septic shock, with threshold values supporting those published in recent guidelines.