Bleeding rates necessary for detecting acute gastrointestinal bleeding with technetium-99m-labeled red blood cells in an experimental model

Journal Article · Wed Apr 01 04:00:00 EST 1987 · J. Nucl. Med.; (United States)

OSTI ID:6500616

Thorne, D A; Datz, F L; Remley, K; Christian, P E

Proponents of (/sup 99m/Tc)sulfur colloid for GI bleeding studies argue that, although labeled red blood cells are useful for intermittent bleeding, they are not capable of detecting low bleeding rates. Studies of dogs with experimental GI bleeding have indicated bleeding rates of 0.05 ml/min can be detected with (/sup 99m/Tc)sulfur colloid. Since similar data in the dog model were unavailable for /sup 99m/Tc-labeled red blood cells, we undertook this study. To simulate lower GI bleeding, catheters were inserted into the bowel lumen. Each dog's blood was labeled with /sup 99m/Tc using an in vitro technique. Venous blood was then withdrawn and re-infused into the lumen of the bowel using a Harvard pump. Fourteen dogs were studied, ten receiving a bleeding rate from 4.6-0.02 ml/min in the descending colon and four with proximal jejunal bleeds of 0.20-0.02 ml/min. Bleeding rates of 4.6-0.2 ml/min were detected within 10 min in the colon and bleeding rates as low as 0.04 ml/min were seen by 55 min. Slower bleeding rates were not detected. Similar findings were noted for proximal jejunal bleeds. Based on the time of appearance, a minimum volume of approximately 2-3 ml labeled blood was necessary to detect bleeding. We conclude that /sup 99m/Tc-labeled RBCs are sensitive for low bleeding rates in the dog model. The rates are comparable to those described for (/sup 99m/Tc)sulfur colloid in this experimental setting. The time of appearance of activity is related to the bleeding rate.

• Research Organization: Univ. of Utah School of Medicine, Salt Lake City
• OSTI ID: 6500616
• Journal Information: J. Nucl. Med.; (United States), Journal Name: J. Nucl. Med.; (United States) Vol. 4; ISSN JNMEA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BIOLOGICAL MODELS
BLOOD
BLOOD CELLS
BODY FLUIDS
COLLOIDS
DIAGNOSIS
DIGESTIVE SYSTEM
DISPERSIONS
DOGS
ERYTHROCYTES
GASTROINTESTINAL TRACT
HEMORRHAGE
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
ISOMERIC NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LABELLING
MAMMALS
MATERIALS
NUCLEI
ODD-EVEN NUCLEI
PATHOLOGICAL CHANGES
RADIOISOTOPES
SYMPTOMS
TECHNETIUM 99
TECHNETIUM ISOTOPES
VERTEBRATES
YEARS LIVING RADIOISOTOPES