Accurate triage of lower gastrointestinal bleed (LGIB) - A cohort study

Acute lower gastrointestinal bleeding (LGIB) is a common acute presenting complaint to hospital. Unlike upper gastrointestinal bleeding, the diagnostic and therapeutic approach is not well-standardised. Intensive monitoring and urgent interventions are essential for patients with severe LGIB. The aim of this study is to investigate factors that predict severe LGIB and develop a clinical predictor tool to accurately triage LGIB in the emergency department of a busy metropolitan teaching hospital.

We retrospectively identified all adult patients who presented to Middlemore Hospital Emergency Department with LGIB over a one year period. We recorded demographic variables, Charlson Co-morbidities Index, use of anticoagulation, examination findings, vital signs on arrival, laboratory test results, treatment plans and further investigations results. We then identified a subgroup of patients who suffered severe LGIB.

A total of 668 patients presented with an initial triage diagnosis of LGIB. 83 of these patients (20%) developed severe LGIB. Binary logistic regression analysis identified four independent risk factors for severe LGIB: use of aspirin, history of collapse, haemoglobin on presentation of less than 100 mg/dl and albumin of less than 38 g/l.

We have developed a clinical prediction tool for severe LGIB in our population with a negative predictive value (NPV) of 88% and a positive predictive value (PPV) of 44% respectively. We aim to validate the clinical prediction tool in a further cohort to ensure stability of the multivariate model.