The diagnostic value of serum urea/creatinine ratio in distinguishing between upper and lower gastrointestinal bleeding. A prospective study.
The predictive value of a urea/creatinine ratio > or = 100 for indicating upper gastrointestinal bleeding was evaluated in 78 consecutive patients with a history of gastrointestinal bleeding 24 hours or less before admission. Serum beta-2-microglobulin was measured to elucidate whether renal hypoperfusion plays a part in elevation of the urea/creatinine ratio. The predictive value of a urea/creatinine ratio > or = 100 in terms of upper gastrointestinal bleeding, was 95% (95% confidence interval (CI): 83-99%), whereas the predictive value of a urea/creatinine ratio < 100, indicating lower gastrointestinal bleeding, was 41% (CI: 25-59%). No statistically significant differences were found between serum beta-2-microglobulin levels in upper and lower gastrointestinal bleeders. We conclude that a urea/creatinine ratio > or = 100 strongly indicates an upper gastrointestinal bleeding source and that the main cause of a high ratio is not renal hypoperfusion.
Mortensen
P B
PB
Department of Surgical Gastroenterology A, Aalborg Hospital.
Nøhr
M
M
Møller-Petersen
J F
JF
Balslev
I
I
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003404:Creatinine / Q000097:blood*; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D014508:Urea / Q000097:blood*
D014508:Urea; D003404:Creatinine