Rethinking an Algorithm: The Utility of the Techinicium 99 m Labeled Red Cell (RBC) Scanning for Lower Gastrointestinal Bleeding (LGIB)

Purpose: Technetium 99 m (99 m Tc) labeled scan is often done to localize bleeding to facilitate treatment. No level 1 or 2 data supports this approach. The aim of this study was to determine the correlation between site of bleeding by nuclear scan and findings at surgery, angiogram or colonoscopy. Methods: Records of patients admitted to Cooper University Hospital from January 2001-December 2005 with LGIB who had 99mTc scan were analyzed. Results: 164 of 170 patients were eligible to be evaluated. There were 45 positive (27.5%) and 119 negative scans (72.5%). 21 of 45 patients with positive scans had angiography. 7 patients (33.3%) had positive and 14 (66.6%) negative angiograms. In 6 patients (85.7%) with (+) angiograms, there was correlation on the area of bleed as seen on the 99 m Tc scan (p = 0.125). 20 patients, in the positive scan group, required surgery. In 15 (75%) the findings at surgery correlated with the scan result (p = 0.04). 31 patients (68.8%) with positive scan had colonoscopy. There was correlation in 27 patients (87.0%) (p < 0.001). The patients with (+) scan received a total of 372 (8.2 per patient) transfusions of packed red blood cells (PRBC) compared to 333 (2.7 per patients) transfusions in patients with (–) scans. Surgeons documented in 7 patients that the result of scan influenced surgery. Patients with (+) and (–) scans had similar rates of colonoscopy (73.35% vs 76.4%), hospital length of stay (14.3 vs 12.10 days), while mortality rate was (8.8% vs 6.72%) respectively, Conclusion: 99 m Tc scan has low yield in the evaluation of LGIB. However when positive, they tend to correlate with findings at angiogram, surgery and colonoscopy.