BACKGROUND Blood lactate levels and central venous oxygen saturation (ScvO(2)) are known to be useful indicators of global tissue hypoxia. However, it is unclear whether ScvO(2) correlates with lactate levels when measured simultaneously and whether changes in ScvO(2) or lactate levels in serial measurements have prognostic value. We investigated the correlation between ScvO(2) and lactate levels measured simultaneously and their association with clinical outcomes.

METHODS We performed a prospective observational study of patients with severe systemic inflammatory response syndrome (SIRS) and severe sepsis who were admitted to the medical intensive care unit. ScvO(2) and lactate levels were measured simultaneously at the time of study enrollment, every 6 h for 24 h, and then every 24 h until the goal was reached.

RESULTS Twenty-five patients were enrolled in the study; 13 have died and 12 have survived. There was no correlation between lactate levels and ScvO(2). Neither lactate levels nor ScvO(2) at the time of admission differed between nonsurvivors and survivors. Normalization of lactate levels within 48 h was significantly associated with survival.

CONCLUSIONS In patients with severe SIRS and severe sepsis, simultaneously measured ScvO(2) and lactate levels showed no correlation, and normalization of lactate levels within 48 h was a predictive factor for survival.