title: Impact of protamine dose on activated clotting time and thromboelastography in infants and small children undergoing cardiopulmonary bypass.
abstract: OBJECTIVE
  To study the effect of two protamine-dosing strategies on activated clotting time (ACT) and thromboelastography (TEG).
  
  
  BACKGROUND
  Protamine dosage based on neutralizing heparin present in the combined estimated blood volumes (EBVs) of the patient and cardiopulmonary bypass (CPB) pump may result in excess protamine and contributes toward a coagulopathy that can be detected by ACT and TEG in pediatric patients.
  
  
  METHODS
  A total of 100 pediatric patients 1 month to ≤5 years of age undergoing CPB were included in this retrospective before/after design study. Combined-EBV group consisted of 50 consecutive patients whose protamine dose was calculated to neutralize heparin in the combined EBVs of the patient and the pump. Pt-EBV group consisted of the next 50 consecutive patients whose protamine dose was calculated to neutralize heparin in the patient's EBV.
  
  
  RESULTS
  Baseline and postprotamine ACTs were similar between groups. Postprotamine heparin assay (Hepcon) showed the absence of residual heparin in both groups. Postprotamine kaolin-heparinase TEG showed that R was prolonged by 7.5 min in the Combined-EBV group compared with the Pt-EBV group (mean R of 20.17 vs. 12.4 min, respectively, P < 0.001). Increasing doses of protamine were associated with a corresponding, but nonlinear increase in R. There was no significant difference in the changes for K, alpha, and MA between the groups.
  
  
  CONCLUSIONS
  Automated protamine titration with a protamine dosage based on Pt-EBV can adequately neutralize heparin as assessed by ACT while minimizing prolonging clot initiation time as measured by TEG.
authors.affiliation: Division of Pediatric Anesthesiology and Pain Medicine, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, AR, USA. nischal.gautam@gmail.com
authors.forename: Nischal K
authors.initials: NK
authors.lastname: Gautam
authors.forename: Michael L
authors.initials: ML
authors.lastname: Schmitz
authors.forename: Dale
authors.initials: D
authors.lastname: Harrison
authors.forename: Luis M
authors.initials: LM
authors.lastname: Zabala
authors.forename: Pamela
authors.initials: P
authors.lastname: Killebrew
authors.forename: Ryan H
authors.initials: RH
authors.lastname: Belcher
authors.forename: Parthak
authors.initials: P
authors.lastname: Prodhan
authors.forename: Wesley
authors.initials: W
authors.lastname: McKamie
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Norvell
mesh_terms: D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D019090:Case Management; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D005260:Female; D006493:Heparin / Q000009:adverse effects / Q000627:therapeutic use; D006494:Heparin Antagonists / Q000008:administration & dosage* / Q000494:pharmacology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011479:Protamines / Q000008:administration & dosage* / Q000494:pharmacology*; D012044:Regression Analysis; D013916:Thrombelastography / Q000187:drug effects*; D014914:Whole Blood Coagulation Time
chemical_list: D000925:Anticoagulants; D006494:Heparin Antagonists; D011479:Protamines; D006493:Heparin