Delayed Coagulopathy Secondary to Crotaline Envenomation Following Initial Control with Crotalidae Polyvalent Immune Fab: A Retrospective Case Series

Background: Recurrent coagulopathy and thrombocytopenia after Crotaline envenomations has been previously described in patients initially controlled with Crotalidae polyvalent immune Fab antivenom(FabAV). The necessity of treatment of this recurrent coagulopathy is uncertain. We present 3cases of children 2-13 y/o with severe recurrent coagulopathy successfully treated with delayed administration of FabAV. Case Report: 1:9yo M bitten on the left heel. His initial labs: INR1.56 fibrinogen(Fib)180mg/dL and platelets(PLT)177k/ mu L. He as treated with a total of 13 vials FabAV over then next 20hrs and discharged 2days after the initial bite with normal coags. He returned on day7 with INR>7, low Fib and PLT80. He was treated twice with 1U FFP, each time with only transient improvement of his labs. After the administration of 4vials FabAV, his parameters permanently normalized. 2: 13yo F bitten on her right foot Initial labs: INR1.2 Fib342 and PLT296. She received 16vials FabAV over 15hrs and was discharge 28hrs after her bite with normal lab parameters. She returned on day6 with INR>7, Fib35 and PLT238. She received an additional of 12 vials and was discharged on day7 with normal lab values. 3: 3yo M bitten multiple times in legs. He received 12vials FabAV prior to his first set of labs which revealed INR1.5, Fib116, and PLT194. He received an additional 10vials to stop the progression of swelling. He was discharge less then 48hrs after the bite, with INR1.5 and Fib12.0 Fib