Early Predictors of Severe Lower Gastrointestinal Bleeding and Adverse Outcomes: A Prospective Study

Background & Aims: Unlike in upper tract bleeding, prognostic factors for ongoing or recurrent bleeding from the lower gastrointestinal tract have not been well-defined. The aim of this study was to identify risk factors for severe lower gastrointestinal bleeding and for significant adverse outcomes. Methods: All patients seeking attention at a university emergency department for gastrointestinal bleeding were prospectively identified during a 3-year period. Ninety-four of 448 (21%) admitted patients had lower gastrointestinal bleeding. Clinical predictors available in the first hour of evaluation were recorded. The primary outcome, severe lower gastrointestinal bleeding, was defined as gross blood per rectum after leaving the emergency department associated with either abnormal vital signs (systolic blood pressure < 100 mm Hg or heart rate > 100/min) or more than a 2-unit blood transfusion during the hospitalization. Significant adverse outcomes, including death, were tabulated. Results: Thirty-seven patients (39%) had severe lower gastrointestinal bleeding. Independent risk factors for severe lower gastrointestinal bleeding were initial hematocrit <= 35% (odds ratio [OR], 6.3; 95% confidence interval [CI], 2.2-16.7); presence of abnormal vital signs (systolic blood pressure < 100 mm Hg or heart rate > 100/min) 1 hour after initial medical evaluation (OR, 4.3; 95% CI, 1.4-12.5); and gross blood on initial rectal examination (OR, 3.9; 95% CI, 1.2-13.2). Nineteen patients (20%) experienced a significant adverse outcome, including 3 deaths. The main independent predictor of adverse outcomes was severe lower gastrointestinal bleeding (OR, 5.3; 95% CI, 1.7-16.5). Conclusions: Risk factors are available in the first hour of evaluation in the emergency department to identify patients at risk for severe lower gastrointestinal bleeding. Severe lower gastrointestinal bleeding is a significant risk factor for global adverse outcomes.