PREDICTIVE VALUE OF PLASMA UREA: CREATININE RATIO IN PATIENTS PRESENTING WITH MELAENA.

The usefulness of plasma urea:creatinine ratio in predicting the site of bleeding was studied in 40 patients admitted with melaena. Patients presenting with frank haematemesis and those in whom the site of bleeding could not be ascertained were excluded from the study. In 26 patients the source of bleeding was above the ligament of Trietz, while in 14 the source was below this level. In 22 of 26 (84.6%) patients with upper gastrointestinal bleeding, the urea:creatinine ratio was more than 36. In only 2 of 14 patients with lower gastrointestinal bleeding the ratio was similarly raised (p < 0.001). Our study suggests that urea:creatinine ratio of 36 or more has a positive predictive value for upper gastrointestinal bleeding.