title: Recurrent coagulopathy and thrombocytopenia in children treated with crotalidae polyvalent immune fab: a case series.
abstract: OBJECTIVE
  Recurrent signs and symptoms after initial treatment and control of coagulopathy and thrombocytopenia after American pit viper (crotaline) envenomations have been previously described in patients treated with Crotalidae polyvalent immune Fab antivenom (FabAV). The significance and necessity of treatment of these recurrent abnormalities are uncertain. Our goal was to further characterize recurrent coagulopathy or thrombocytopenia in pediatric patients.
  
  
  METHODS
  All cases presenting to our Toxicology Consult Service, which covers 6 hospitals in a metropolitan area, from May 2007 to April 2008 with recurrent coagulopathy after initial control with FabAV were included and retrospectively reviewed.
  
  
  RESULTS
  Four cases of pediatric patients are presented who presented with recurrent coagulopathy and/or thrombocytopenia after initial control with FabAV. The patients were all treated with delayed administration of FabAV with variable results. Blood products administered without concurrent FabAV were of limited use. The laboratory abnormalities took up to 18 days to resolve in one case. One patient developed hemodynamically significant spontaneous bleeding.
  
  
  CONCLUSIONS
  The cases presented here suggest administration of FabAV may correct delayed coagulopathy associated with crotaline envenomations. The first 3 cases illustrate that in the face of severe derangements in laboratory values, most envenomated patients treated with FabAV do not develop significant bleeding. These cases may respond to additional antivenom alone. However, case 4 illustrates that hemodynamically significant spontaneous bleeding can occur. Until more data are available, readministration of FabAV is a reasonable first-line therapy for delayed coagulopathy associated with crotaline envenomations.
authors.affiliation: Division of Medical Toxicology, Department of Emergency Medicine, University of California, San Diego, CA, USA. admiller@writeme.com
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Miller
authors.forename: Michael C
authors.initials: MC
authors.lastname: Young
authors.forename: Megan C
authors.initials: MC
authors.lastname: DeMott
authors.forename: Binh T
authors.initials: BT
authors.lastname: Ly
authors.forename: Richard F
authors.initials: RF
authors.lastname: Clark
mesh_terms: D000293:Adolescent; D000818:Animals; D000997:Antivenins / Q000009:adverse effects* / Q000627:therapeutic use; D001778:Blood Coagulation Disorders / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D016913:Blood Component Transfusion / Q000379:methods; D002648:Child; D002675:Child, Preschool; D003435:Crotalid Venoms; D017839:Crotalus; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007140:Immunoglobulin Fab Fragments; D007128:Immunoglobulin Fragments / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D055502:Secondary Prevention; D012909:Snake Bites / Q000188:drug therapy*; D013921:Thrombocytopenia / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy
chemical_list: D000997:Antivenins; D003435:Crotalid Venoms; C431183:Crotalidae Polyvalent immune Fab; D007140:Immunoglobulin Fab Fragments; D007128:Immunoglobulin Fragments