125 Lactate as a Mortality Predictor in Emergency Department Patients With Gastrointestinal Hemorrhage

Abstract

The prognostic value of emergency department lactate levels has been well studied in conditions such as sepsis and trauma; however, limited data exists for its use in gastrointestinal hemorrhage (GIH). Additionally, the presence of hypotension has also been cited as predictive of mortality in GIH but the role of lactate is not defined. The primary objective of this study was to compare mortality in emergency department GIH patients using lactate as the prognostic indicator. This was a retrospective cohort study in an urban, tertiary care teaching hospital. A total of 269 patients with GIH had lactate levels obtained between October 1st, 2008 and May 31st, 2013. Inclusion criteria were all individuals presenting in the ED who were ≥18 years of age with the clinical impression of a GIH who had a lactate level obtained at the discretion of the treating physician. The main outcome measure was in-hospital mortality with a secondary outcome comparing the predictive value of lactate in patients with hypotension (SBP < 90) and without hypotension (SBP ≥ 90). Of the 269 patients in this analysis, 20 (7.4%) expired. The mean lactate of survivors was 2.5 mmol/L (95% CI 2.3-2.7) and the mean lactate of expired patients was 5.6 mmol/L (95% CI 3.6-7.6). 24 (8.9%) patients were hypotensive with 29.2% in-hospital mortality. In the subset of 245 normotensive patients, mortality associated with a lactate level < 2.5 mmol/L was 1.9%, a lactate 2.5-3.9 mmol/L was 4.9%, and a lactate ≥ 4 mmol/L was 18.6% (p<0.0001). Lactate is predictive of mortality in emergency department patients with GIH. This study highlights that elevated lactate levels were predictive of mortality when hypotension was absent. This indicates that lactate may be a useful predictor of mortality when used in conjunction with traditional variables.