title: Can the blood urea nitrogen/creatinine ratio distinguish upper from lower gastrointestinal bleeding?
abstract: We wanted to know if the blood urea nitrogen to creatinine (BUN/Cr) ratio could help distinguish upper from lower gastrointestinal bleeding. We analyzed retrospectively patients admitted to our hospital for gastrointestinal bleeding over the past 5 years. A total of 126 patients represented 74 upper bleeds and 52 lower bleeds. The mean BUN/Cr ratio was significantly higher in upper than lower bleeders, 34.8 and 17.8 respectively (p less than 0.001). No lower bleeder had a ratio of greater than or equal to 36, whereas 38% of upper bleeders had a ratio of greater than or equal to 36. The BUN/Cr ratio may be an easy, cheap method of distinguishing upper from lower gastrointestinal bleeding in some cases. A BUN/Cr ratio of greater than or equal to 36 suggests upper gastrointestinal bleeding, whereas a ratio of less than 36 is not helpful in locating the source of bleeding.
authors.affiliation: Department of Gastroenterology, Bridgeport Hospital, Connecticut.
authors.forename: R J
authors.initials: RJ
authors.lastname: Richards
authors.forename: M B
authors.initials: MB
authors.lastname: Donica
authors.forename: D
authors.initials: D
authors.lastname: Grayer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001806:Blood Urea Nitrogen; D003404:Creatinine / Q000097:blood*; D003937:Diagnosis, Differential; D004378:Duodenal Diseases / Q000097:blood / Q000175:diagnosis; D006471:Gastrointestinal Hemorrhage / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D007410:Intestinal Diseases / Q000097:blood / Q000175:diagnosis*; D008875:Middle Aged; D012189:Retrospective Studies; D013272:Stomach Diseases / Q000097:blood / Q000175:diagnosis*
chemical_list: D003404:Creatinine