Lactate is associated with increased 10-day mortality in acute medical patients: a hospital-based cohort study

An increased lactate level is related to increased mortality in subpopulations of critically ill patients. The aim of this study was to investigate whether lactate was related to mortality in an emergency department (ED) setting of undifferentiated medical patients. All adult patients admitted from March 2009 to August 2011 to a medical ED with lactate measured within 6 h after arrival were studied. Lactate was stratified into 1-mmol/l intervals and analysed in a multivariate logistic regression analysis. A total of 5317 patients were included, 46.9% men, median age 71 years (5-95% percentiles 25-90 years). The median lactate level was 1.2 mmol/l (5-95% percentiles 0.6-3.8 mmol/l, range 0.2-22 mmol/l). Lactate was associated with 10-day mortality independent of age, comorbidity and presence of hypotension, with an odds ratio of 1.54 (95% confidence interval 1.44-1.63) per 1 mmol/l increase. Lactate is an independent predictor of 10-day mortality among patients admitted to a medical ED.