The Effect of Adjunctive Fresh Frozen Plasma Administration on Coagulation Parameters and Survival in a Canine Model of Antivenom-treated Brown Snake Envenoming

Abstract

This study aimed to assess the effects of dugite envenoming on blood coagulation and platelet count in a canine model, and the efficacy of fresh frozen plasma (FFP) in reversing the clotting disorder after both adequate and inadequate venom neutralization. Following initial dosing and administration studies, an intravenous venom dose of 1μg/kg was administered to eleven dogs. This was followed 30 minutes later by antivenom in either adequate or inadequate doses. A further 30 minutes later, the animals were given either two units of their own FFP or saline. Fibrinogen, aPTT and platelet levels were monitored for eight hours. Of the six study dogs given antivenom plus FFP, two died at around 60 to 90 minutes post envenoming, at the end of the FFP infusions, and all but one of the survivors had persistent afibrinogenaemia. Of the five study dogs given antivenom and no FFP, all but one had return of detectable fibrinogen at eight hours after envenoming. The platelet count fell in all animals with recovery independent of antivenom dose, administration of FFP, or regeneration of fibrinogen. Post mortem examinations of dogs that died during dosage and administration studies showed massive intracardiac clots. We conclude that early death from Brown Snake envenoming may be due to massive intravascular clotting. FFP administration was associated with persistent afibrinogenaemia regardless of antivenom dose. In the absence of any evidence for its efficacy, this study suggests that the role of FFP after Brown Snake envenoming should be reconsidered.

Presumptive intraperitoneal envenomation resulting in hemoperitoneum and acute abdominal pain in a dog

“…The administration of FFP in crotalid envenomation victims is controversial. Clinicians must consider both the need to replenish clotting factors lost to consumption and the concern that the additional clotting factors may result in acceleration of fibrinolysis and exacerbate hemorrhage until all venom is neutralized . A study evaluating the efficacy of FFP to reverse venom‐induced coagulopathy in dogs envenomated with brown snake venom showed that most dogs receiving plasma were afibrinogenemic and death only occurred in dogs that received plasma .…”

“…Clinicians must consider both the need to replenish clotting factors lost to consumption and the concern that the additional clotting factors may result in acceleration of fibrinolysis and exacerbate hemorrhage until all venom is neutralized . A study evaluating the efficacy of FFP to reverse venom‐induced coagulopathy in dogs envenomated with brown snake venom showed that most dogs receiving plasma were afibrinogenemic and death only occurred in dogs that received plasma . Alternatively, a retrospective study in human medicine showed early FFP administration was associated with earlier improvement of coagulation function within 4 hours and was not associated with hemorrhage or death .…”

“…17,18 A study evaluating the efficacy of FFP to reverse venom-induced coagulopathy in dogs envenomated with brown snake venom showed that most dogs receiving plasma were afibrinogenemic and death only occurred in dogs that received plasma. 18 Alternatively, a retrospective study in human medicine showed early FFP administration was associated with earlier improvement of coagulation function within 4 hours and was not associated with hemorrhage or death. 17 In this case, the authors administered FFP after antivenom was administered to combat ongoing hemorrhage and volume depletion while first addressing the need to bind the circulating venom proteins.…”

Overview and controversies in the medical management of pit viper envenomation in the dog

“…Such an effect can accelerate fibrinolysis, which will enhance further bleeding through the release of fibrin degradation products . One canine study from Australia assessed FFP and antivenom in dogs with brown snake (genus Pseudonaja , family Elapidae ) envenomation . Persistent afibrinogenemia was present in both study groups, one having received antivenom only and the other receiving antivenom and FFP .…”

“…One canine study from Australia assessed FFP and antivenom in dogs with brown snake (genus Pseudonaja , family Elapidae ) envenomation . Persistent afibrinogenemia was present in both study groups, one having received antivenom only and the other receiving antivenom and FFP . Heparin should never be used because it is ineffective for treating the venom‐induced coagulopathy and because of its potentiating effect on antithrombin .…”