Heparin treatment in thrombin-induced disseminated intravascular coagulation in the baboon

We postulated that low-dose heparin (10 IU/kg.hr) administered as a continuous iv infusion may prevent or ameliorate the induction of thrombin-induced disseminated intravascular coagulation in baboons under general anesthesia. In a nonrandomized experiment lasting 8 hrs, animals were divided into three groups: 11 received thrombin only (group A); ten were pretreated with heparin before thrombin administration (group B); and 15 received heparin 2 hrs after disseminated intravascular coagulation was induced with thrombin (group C). All animals were monitored hemodynamically and coagulation tests were performed hourly. Tests included the following: one-stage prothrombin ratio; activated partial thromboplastin time; fibrinogen and fibrin degradation products; thrombin time; plasma fibrinogen level; antithrombin III and activated clotting time. After the acute phase of the experiment, the animals were observed for 6 days and a postmortem examination was performed on a survivor of each group.

Six (55%) group A animals died within 6 days, while there were no deaths in group B and one animal (7%) died in group C. In group C, the administration of heparin could not normalize the clotting profile, but the mortality rate was significantly less than in group A. The prophylactic administration of heparin in group B prevented the induction of disseminated intravascular coagulation. The postmortem findings were of interest, but no statistically valid conclusions could be made, as only one autopsy was done for each group. However, the results suggest that heparin pretreatment may protect against lung edema and liver necrosis.

The results suggest that heparin, in a dose of 10 IU/kg.hr iv, could possibly be safely used in patients at high risk of developing disseminated intravascular coagulation and in those patients with established disseminated intravascular coagulation.