Role of Arterial Lactate and Lactate Clearance in Risk Stratification of Patients with Upper Gastrointestinal Bleeding Presenting to the Emergency Department for use at Primary Health Care Level

Upper gastrointestinal bleeding is a common presenting complaint in the emergency department (ED) and carries a small but significant mortality rate. In spite of the availability of various scoring systems, risk stratification for in hospital morbidity and mortality remains difficult. There is no single test that can reliably predict active bleeding from the upper gastrointestinal tract for use at primary health level. To study the role of lactate clearance as a predictor of active bleeding and also to determine whether an ED arterial lactate can predict adverse outcomes like increased hospital length of stay, in hospital, 30-day and 60-day mortality. Prospective single centre observational study at a tertiary hospital in north Kerala that included all stable adult patients who presented with the complaints of hematemesis, melena or both to the ED Arterial lactate was drawn at the bedside, a priori initial arterial lactate cut-off value of 2.2 mmol/L was selected and in patients with lactate value above the cut-off, a second lactate was measured to calculate lactate clearance. Lactate clearance ≤13.39% was found to be associated with a high risk for active bleeding (odds ratio: 23.33; 95% CI = 4.337 to 125.512, P < 0.001). Optimal cut-off points for lactate as well as lactate clearance were derived using receiver operating characteristics curve. Lactate clearance can reliably rule in as well as rule out active bleeding in patients who might seem hemodynamically stable at the initial presentation to the ED.