Implications of negative technetium 99m-labeled red blood cell scintigraphy in patients presenting with lower gastrointestinal bleeding.

BACKGROUND: Lower gastrointestinal (GI) bleeding frequently recurs after negative technetium 99m-labeled red blood cell (RBC) scintigraphy.

METHODS: Between July 1, 1999 and July 31, 2005, 84 negative (99m)Tc-labeled RBC scintigrams were obtained for acute lower GI bleeding. Medical records were abstracted for age, gender, prior history of lower GI hemorrhage, length of hospitalization, initial hematocrit (Hct) and Hct nadir, transfusion requirements, cause of bleeding, use of anticoagulants and/or antiplatelet medications, and rebleeding episodes.

RESULTS: The overall rate of rebleeding was 27% (n = 23). There were no significant associations between any of the patient variables investigated and rebleeding.

CONCLUSIONS: Despite negative (99m)Tc-labeled RBC scintigraphy, more than 25% of patients experience recurrent lower GI bleeding. Patient age, bleeding source, use of anticoagulant/antiplatelet medications, length of stay, admission Hct, Hct nadir, transfusion requirements, and gender are not predictive of the patients who will rebleed.