Studies of GI bleeding with scintigraphy and the influence of vasopressin.

The management of patients with gastrointestinal (GI) bleeding depends on accurate localization of the site of hemorrhage. Endoscopy and arteriography, although successful in achieving this goal in the majority of patients, are invasive and have other shortcomings. The introduction of the 99mTc-sulfur colloid technique has greatly simplified the evaluation and management of these patients. This test is useful in detecting and localizing the bleeding site in the lower GI tract. Scintigraphy is now used as the initial study of choice in patients with rectal bleeding. Advances made in angiography and nuclear medicine techniques also have resulted in improved management of patients. Conservative approaches succeed in controlling hemorrhage in most patients. Vasopressin is the most widely tested agent and has been adopted by many as the preferred preparation for this purpose. Before the introduction of the 99mTc-sulfur colloid technique, angiography was used to monitor the effectiveness of this drug, whether administered intravenously or intraarterially. With the use of scintigraphy and intravenous administration of vasopressin, these patients now can be managed noninvasively. Only when the intravenous Pitressin infusion fails to stop hemorrhage, is the intraarterial approach considered. Surgery is used as a last resort when these measures fail to stop the bleeding.