Lactic Acidosis as a Prognostic Factor and a Therapeutic Guideline for Severe Sepsis and Septic Shock

Park, Jong Su; Lee, Sung Woo; Kim, Nak Hoon; Cho, Young Duck; Shin, Jun Hyun; Choi, Sung Hyuk; Hong, Yun Sik

Abstract

PURPOSE: To examine the clinical utility of lactic acidosis as a predictor of in-hospital mortality and as an early therapeutic marker in severe sepsis and septic shock patients.
METHODS
We conducted a prospective observational study. Patients visiting the emergency department from January 2005 to October 2006 who were suspected to have severe sepsis and septic shock were candidates for enrollment. Therapies in the emergency department consisted of early goal-directed resuscitation and employed central venous access, antibiotics, fluid resuscitation, mechanical ventilation, vasoactive agent, and inotropes as required. We measured hemodynamic variables, arterial blood gases, and serum lactate at presentation (0 hours) and at four hours. The SAPS II at emergency department and SOFA score at 0 hours, 4 hours, 24 hours, 48 hours and 72 hours were recorded.
RESULTS
A total of 102 patients were enrolled during the study period. Data were presented as mean+/-SD. Thirtyfour patients died in the hospital, eighteen patients of them within 72 hours after admission. Septic shock was encountered in 44 patients. Non-survivors had significantly lower pH, higher serum lactate level, higher SAPS II scores, lower mean arterial blood pressure, higher heart rates, and lower PaO2/FiO2 values at 0 and 4 hours than did survivors. During the first four hours, persistent lactic acidosis and high SAPS II scores were independently associated with mortality. Although most patients achieved the therapeutic goals, excepting central venous oxygen saturation in nonsurvivors, patients with persistent lactic acidosis at 0 and 4 hours had significantly high in-hospital mortality and early overall mortality than other patients (80.0%, p=0.000, 65.0%, p=0.000, respectively). Patients recovering from lactic acidosis at 4 hours showed lower in-hospital mortality and early overall mortality than patients with persistent lactic acidosis (50.0% vs. 80.0%, p=0.070, 14.3% vs. 65.0%, p=0.004).
CONCLUSION
Persistent lactic acidosis was found to be an independent variable for predicting mortality and morbidity. Persistent lactic acidosis may be used as a prognostic and treatment indicator during the resuscitation of patients with severe sepsis and septic shock in an emergency department.