Effect of internal hemorrhage on fibrin(ogen) degradation products in canine blood.

To determine effects of internal hemorrhage on fibrin(ogen) degradation products, blood was pumped from catheters in the jugular veins of 7 anesthetized dogs into extravascular sites in the same dogs. Blood (25 ml/kg of body weight) was transported into their peritoneal cavities (3 dogs) or into the muscle of the pelvic limbs (4 dogs). Blood samples were obtained periodically from these dogs for 4 days after the injections were given. Fibrin(ogen) degradation products (FDP) could not be detected in any of these samples by standard procedures with a commonly used clinical assay, based on the agglutination of antibody-coated latex beads. Even when the assay was modified to make it 2.5 times as sensitive, FDP was not detected. Seemingly, extravascular blood from internal hemorrhage is unlikely to supply enough FDP to the circulating blood to produce clinically important increases in FDP concentrations.