Serum Fibrin/ Fibrinogen Degradation Products (FDP) after Experimental Pulmonary Embolism in Dogs

In previous clinical studies we reported elevated serum FDP values after pulmonary embolism. We detected high values in only 50% of patients and the elevation was transitory. In order to determine the exact time and magnitude of the FDP elevation, and whether the increase was consistent, experimental pulmonary emboli were produced in dogs.

Under pentobarbitone anaesthesia emboli of autologous clot were injected via the femoral vein. FDP, platelets and fibrinogen were estimated on frequent samples taken via a jugular vein catheter. The FDP were measured by the Tanned Red Cell Haemagglutination Inhibition Immunoassay with reagents specific for dog fibrinogen.

It 5 control animals FDP values rose gradually during 8-12 hours of anaesthesia. In 11 dogs receiving 3 ml/ kg of clot the mean FDP rose from 9 ug/ml at rest to 142 ug/ml (Range 9–16100 ug/ml). The peak of FDP was reached in 30-60 minutes and remained significantly above control values for up to 7 hours. These data support our view thai’FDP measurement is valuable in the diagnosis of venous thrombo-embolic disease.