Differentiating between upper and lower GIB can be challenging.
A recent review evaluated the accuracy of historical features, symptoms, signs, and lab values in distinguishing between UGIB and LGIB.
Features with the highest likelihood for identifying UGIB included:
Melenic stool on exam (LR 25)
A prior history of UGIB (LR 6.2)
Serum urea:creatinine ratio > 30 (LR 7.5)
Features that increased the likelihood of severe UGIB (defined as requiring blood transfusion, need for urgent endoscopy, surgery, or interventional radiology) included:
Heart rate > 100 bpm (LR 4.9)
Hemoglobin < 8 g/dL (LR 6.2)
History of cirrhosis or cancer (LR 3.7)
For patients with an UGIB, the Blatchford Score can be used to determine the need for urgent intervention. Those with a Blatchford Score of 0 have a low likelihood for severe UGIB and may not need emergent intervention.
Srygley FD, et al. Does this patient have a severe upper gastrointestinal bleed? JAMA 2012;307:1072-9.