Elevated serum lactate in emergency department patients predicts hospital admission unrelated to diagnosis - but not more

Purpose: The value of lactate as a screening biomarker in the emergency department is debated. We analysed all unselected patients in the emergency department with serum lactate measured with regard to different outcome parameters. Material and Methods: In a retrospective single centre study, we analysed all digitalized patient data of a two-week period of all patients >= 18 where a serum lactate was measured. The lactate levels as well as demographic and other laboratory data were correlated in a logistic regression analysis, univariable as well as multivariable, with the outcome parameters. Results: A total of 1157 patients contacted the emergency department of which 587 were included. The average lactate level was 2,08mmol/l (SD +/- 1.51, median 1.73). A total of 313 patients were admitted to hospital, 274 treated as outpatients. Their median lactate levels were 2.0mmol/l (min/max 0.6-18mmol/l) and 1.5mmol/l (min/max 0.5-7.4mmol/l), respectively. Univariable regression analysis for hospital admission showed an odds ratio of 1756 (p< 0.001), multivariable regression analysis showed a positive correlation for hospital admission for lactate (OR 1532, p = 0.004). There was no correlation with admission to ICU, length of stay or a relation to a certain diagnostic group. Conclusions: Screening lactate levels in unselected emergency department patients do not have a clinical relevance yet.