title: Prevalence of heparin-dependent platelet antibodies in children after cardiopulmonary bypass.
abstract: OBJECTIVE
  To determine the prevalence of heparin-dependent platelet antibodies (HDPA) in children requiring heparin for >5 days after cardiopulmonary bypass surgery.
  
  
  METHODS
  Prospective, observational study.
  
  
  METHODS
  Tertiary care pediatric intensive care unit.
  
  
  METHODS
  Thirty children were enrolled: 15 patients <30 days old and 15 patients between 30 days and 12 yrs of age.
  
  
  METHODS
  Detection of HDPA by heparin-platelet factor 4 enzyme-linked immunosorbent assay after 5-10 days of postoperative heparin exposure. Positive or equivocal results were confirmed with serotonin release assay.
  
  
  RESULTS
  There were no confirmed cases of HDPA in this study (95% confidence interval 0-11.6%). Despite the lack of HDPA, the study population was at high risk of thrombosis with symptomatic clot developing in six patients (20%). Clinical models developed in adults to determine the pretest risk of heparin-induced thrombocytopenia were not valid in this study population.
  
  
  CONCLUSIONS
  The prevalence of HDPA in children after cardiopulmonary bypass surgery is low. After bypass surgery, critically ill children are at risk of developing thrombosis from multiple etiologies, and suspicion of heparin-induced thrombocytopenia needs to be confirmed with laboratory testing including a functional assay.
authors.affiliation: Department of Pediatrics, Critical Care Medicine, Children's Hospital of Wisconsin and Medical College of Wisconsin, Milwaukee, WI 53226, USA. shanson@mcw.edu
authors.forename: Sheila J
authors.initials: SJ
authors.lastname: Hanson
authors.forename: Rowena C
authors.initials: RC
authors.lastname: Punzalan
authors.forename: Nancy
authors.initials: N
authors.lastname: Ghanayem
authors.forename: Peter
authors.initials: P
authors.lastname: Havens
mesh_terms: D000906:Antibodies / Q000097:blood*; D000925:Anticoagulants / Q000009:adverse effects* / Q000276:immunology; D001792:Blood Platelets / Q000276:immunology*; D002315:Cardiopulmonary Bypass; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006493:Heparin / Q000009:adverse effects* / Q000276:immunology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015278:Intensive Care Units, Pediatric; D008297:Male; D010978:Platelet Factor 4 / Q000276:immunology; D011183:Postoperative Complications / Q000139:chemically induced / Q000276:immunology; D011446:Prospective Studies; D013921:Thrombocytopenia / Q000139:chemically induced / Q000276:immunology
chemical_list: D000906:Antibodies; D000925:Anticoagulants; D010978:Platelet Factor 4; D006493:Heparin