Determination of plasma lactate in the emergency department for the early detection of tissue hypoperfusion in septic patients

Abstract

Objective: To determine the validity of plasma lactate in the emergency department for the early detection of tissue hypoperfusion in septic patients.

Materials and methods: Longitudinal descriptive study. Non probabilistic sampling for convenience. Plasma lactate levels were determined in patients admitted to the emergency department with systemic inflammatory response data and clinical suspicion or documented infection. Follow-up was seven days. Complications were considered if the patients presented septic shock, severe sepsis, entry to intensive care or death.

Results: Ninety patients were included. The mean age was 57.4±20.31. Fifty five percent (n=49) were women. 25% (n=22) of the patients showed complications. Plasma lactate levels were 1.55mmol/L in uncomplicated patients and 3.72mmol/L for complicated patients (p<0.001). The area under the ROC curve was 0.72 (95% CI, 0.575-0.829). The cutoff point that best described the relationship with the probability of complications was that set at 4.2mmol/L. The variables studied that showed a significant association with the probability of complications were edema (p=0.004), and infections of the respiratory tract (p=0.037). A model that included lactate levels, using as adjustment variables edema and the presence of low respiratory tract infection explained between 0.234 and 0.349 of the dependent variant, correctly classifying 80% of the cases.

Conclusion: Plasma lactate is useful in emergency departments as a predictive test for the early detection of patients with tissue hypoperfusion that evolve to severe sepsis, septic shock or death.

Keywords: Hypoxia; Infection; Lactate; Sepsis; Septic shock.