title: Treatment, survival, and thromboembolic outcomes of thrombotic storm in children.
abstract: OBJECTIVE
  To describe the course and management of thrombotic storm in 8 children.
  
  
  METHODS
  Clinical data were collected and analyzed for consecutive children diagnosed with thrombotic storm, aged 6 months to 21 years inclusive, in the context of a single-institution prospective inception cohort study. Thrombotic storm was defined as newly diagnosed multisite venous thromboembolism (VTE) with acute thrombus progression despite conventional or higher than conventional dosing of heparin or low molecular weight heparin. All evaluations and therapies were ordered by the treating physicians in the context of clinical decision making.
  
  
  RESULTS
  Eight of the 178 children with VTE enrolled in the cohort between March 2006 and November 2009 were diagnosed with thrombotic storm. Antiphospholipid antibodies were acutely positive in 6 children, of whom heparin-induced thrombocytopenia was confirmed by serotonin release assay in 2 and atypical in 1. One child died. Five children received a direct thrombin inhibitor, titrated to achieve normalization of markedly elevated D-dimer levels. All children were transitioned to fondaparinux or enoxaparin before receiving extended anticoagulation with warfarin. Immunomodulatory therapy was instituted in all children. During follow-up (median duration, 3 years; range, 2-6 years), 3 of the 7 surviving children experienced recurrent VTE, and 4 children had clinically significant postthrombotic syndrome.
  
  
  CONCLUSIONS
  Thrombotic storm is an infrequent but potentially fatal presentation of VTE in children. Administration of direct thrombin inhibitors and immune modulation can achieve quiescence, although long-term adverse outcomes are common.
authors.affiliation: Department of Pediatrics, The Children's Hospital, University of Colorado School of Medicine, Aurora, CO 80045, USA. marilyn.manco-johnson@ucdenver.edu
authors.forename: Marilyn J
authors.initials: MJ
authors.lastname: Manco-Johnson
authors.forename: Michael
authors.initials: M
authors.lastname: Wang
authors.forename: Neil A
authors.initials: NA
authors.lastname: Goldenberg
authors.forename: Jennifer
authors.initials: J
authors.lastname: Soep
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Gibson
authors.forename: Christine M
authors.initials: CM
authors.lastname: Knoll
authors.forename: Peter M
authors.initials: PM
authors.lastname: Mourani
mesh_terms: D000293:Adolescent; D000925:Anticoagulants / Q000627:therapeutic use; D016736:Antiphospholipid Syndrome / Q000453:epidemiology / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000378:metabolism; D017984:Enoxaparin / Q000627:therapeutic use; D017809:Fatal Outcome; D005260:Female; D000077425:Fondaparinux; D006801:Humans; D056747:Immunomodulation; D008297:Male; D011134:Polysaccharides / Q000627:therapeutic use; D011446:Prospective Studies; D054556:Venous Thromboembolism / Q000188:drug therapy / Q000453:epidemiology / Q000276:immunology* / Q000628:therapy*; D055815:Young Adult
chemical_list: D000925:Anticoagulants; D016207:Cytokines; D017984:Enoxaparin; D011134:Polysaccharides; D000077425:Fondaparinux