Quantitative measurement of gastrointestinal blood loss: I. The use of radioactive Cr 51 in patients with gastrointestinal hemorrhage

Abstract

1. 1. A method for quantitating the amount of blood lost in the feces by means of erythrocytes labeled with radioactive sodium chromate is described. The maximum amount of blood lost by normal subjects is 1.2 ± 0.5 ml., with a range of 0.3 to 2.0 ml. of whole blood per day. 2. 2. The sensitivity of the qualitative benzidine dihydrochloride test to hemoglobin in aqueous solution has been compared with the sensitivity to hemoglobin in homogenized stools. It was found that the sensitivity of the test was approximately 100 times greater for hemoglobin in aqueous solution than for hemoglobin present in the stools. 3. 3. The use of the Cr 51 technic for quantitating blood loss from the gastrointestinal tract, combined with intestinal intubation for localizing the level of bleeding, has been tested in nine cases in which there was difficulty either in establishing that the anemia was due to blood loss or in localizing the level of bleeding by x-ray studies. In eight of the nine cases these technics were of aid in arriving at the correct diagnosis. In one case the interpretation of the Cr 51 and intubation data was not substantiated by the findings at operation.