Prognostic use of lactate to predict inpatient mortality in acute gastrointestinal hemorrhage

Background Gastrointestinal hemorrhage (GIH) is a common complaint seen in the emergency department (ED) and carries a small but significant mortality rate. The principal purpose of this investigation was to determine whether an ED venous lactate as part of initial laboratory studies is predictive of mortality in patients admitted to the hospital for GIH. Methods Retrospective cohort study for 6 years at an urban tertiary referral hospital included all ED patients with the charted diagnosis of acute GIH. Serum lactate was drawn at the bedside as part of patient care after arrival to the ED at the discretion of the clinical team. Clinical parameters and inpatient mortality were collected from the medical record. Optimal cut points for lactate were derived using receiver operating characteristics curves and imputed into a multivariable logistic regression model. Results Of the 2834 medical records that had GIH diagnoses, 1644 had an ED lactate recorded. A lactate greater than 4 mmol/L conferred a 6.4-fold increased odds of in-hospital mortality (94% specificity, P <.001). Controlling for age, initial hematocrit, and heart rate, every 1-point increase in lactate conferred a 1.4-fold increase in the odds of mortality. Conclusions Elevated initial lactate drawn in the ED can be associated with in-hospital mortality for ED patients with acute GIH. Prospective validation studies are warranted.