title: Heparin-induced thrombocytopenia in paediatrics: clinical characteristics, therapy and outcomes.
abstract: OBJECTIVE
  Reports on heparin-induced thrombocytopenia (HIT) in paediatrics are confined to isolated case reports. The objective was to systematically combine the published data.
  
  
  METHODS
  Cases were identified by MEDLINE search and review of bibliographies.
  
  
  METHODS
  We included subjects reported with HIT, collecting patient demographics, clinical and laboratory characteristics, therapeutic regimens and outcomes.
  
  
  RESULTS
  Reports on 70 patients were retrieved. In a majority of children, HIT occurred during hospitalisation in a paediatric ICU. In most patients, the typical onset pattern was reported, although rapid-onset-pattern HIT occurred in some. The median platelet-count nadir was 54x10(9)/l; 11% of reported patients had nadirs in the normal range. Clinical symptoms included isolated thrombocytopenia and solitary or combined venous, arterial and intracardiac thromboembolism, sometimes catheter-related. Pulmonary embolism and major bleeding were rarely described. Confirmatory functional or antigenic testing of HIT antibodies showed a similar cumulative sensitivity of about 88%. An unfavourable outcome (death/limb amputation) was reported in 42.1% of patients without therapy and in 18% of patients treated with danaparoid, lepirudin, or argatroban.
  
  
  CONCLUSIONS
  HIT in children mainly occurs in paediatric intensive care with diagnostic features and outcomes similar to those seen in adults. HIT cannot be ruled out based on normal platelet counts or occurrence after fewer than 5 days of heparin exposure. Children should be presumed to suffer from HIT based on clinical grounds and treated accordingly (immediate heparin withdrawal and alternative anticoagulation). Alternative anticoagulation with danaparoid, lepirudin and argatroban appears to improve outcomes.
authors.affiliation: Clinical Decision Making Research Unit, Academic Teaching Hospital, 6800 Feldkirch, Austria.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Risch
authors.forename: Joachim E
authors.initials: JE
authors.lastname: Fischer
authors.forename: Roberto
authors.initials: R
authors.lastname: Herklotz
authors.forename: Andreas R
authors.initials: AR
authors.lastname: Huber
mesh_terms: D000925:Anticoagulants / Q000009:adverse effects*; D006493:Heparin / Q000009:adverse effects*; D006801:Humans; D015278:Intensive Care Units, Pediatric; D010372:Pediatrics; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000628:therapy*
chemical_list: D000925:Anticoagulants; D006493:Heparin