Effect of heparin in experimental gram-negative septicemia.

Young rabbits were given live encapsulated or heat-hilled Pasteurella multocida by the intraperitoneal route. Those animals given live organisms regularly developed clinical illness, positive blood cultures, positive limulus lysate tests on plasma, leukopenia, thrombocytopenia, and disseminated intravascular coagulation and died. Death occurred in 68% of these rabbits by 12 hr after infection and in 100% by 24 hr. Septicemic animals given heparin as an anticoagulant similarly developed clinical illness, leukopenia, and thrombocytopenia, but no laboratory evidence of disseminated intravascular coagulation. The mortality rate in these animals was 90% 12 hr after infection and 100% 24 hr after infection. None of the animals given heat-killed organisms developed leukopenia, thormbocytopenia, or disseminated intravascular coagulation, and none died. The data show that the survivial rate in septicemic rabbits was not improved with heparin, although fibrinogen consumption (disseminated intravascular coagulation) was abolished.