Abstract

BACKGROUND
Septic shock is a pathophysiologic state of circulatory failure with tissue hypoperfusion. However, it is usually defined as sepsis-induced hypotension not responding to fluid resuscitation, regardless of the objective findings of tissue hypoperfusion such as lactic acidosis or organ failures. Numerous patients with sepsis-induced hypotension present to the emergency department without hyperlactemia or severe organ failure. Hence, we investigated the clinical characteristics and outcomes of patients with septic shock according to the presence of hyperlactatemia or significant organ failure.
METHODS
We conducted a retrospective observational study of adult patients presenting with septic shock in the emergency department of a tertiary care hospital between August 2008 and July 2010. Initial serum lactate was categorized low (<2.5 mmol/L) and high (> or =2.5 mmol/L). Organ failure was assessed by the Sequential Organ Failure Assessment (SOFA) score. Primary outcome measurement was in-hospital mortality.
RESULTS
A total of 227 patients were enrolled. There were 88 (38.8%) patients in the low lactate group, and 139 (61.2%) patients in the high lactate group. Patients with low lactate levels showed a lower mortality rate (6.8% compared with 25.1% of those with high lactate level). The low lactate group showed less rapid heart rate, less severe organ failures and shorter length of stay in the intensive care unit. During the early goal-directed therapy, they required a smaller amount of fluid administration and a lower dose of norepinephrine although other hemodynamic variables were similarly maintained. In particular, if patients showed less severe organ dysfunction (SOFA score < 8) in the low lactate group (n = 45), in-hospital mortality was 0% (adjusted mortality was 1.3% [95% confidence interval = 0.3-5.0]).
CONCLUSION
Patients with septic shock, who were enrolled according to the traditional definition, showed a very favorable outcome if they did not have hyperlactatemia or significant organ failure.

• Keywords: lactate;mortality;sepsis;septic shock;