title: Changing systems for measuring activated clotting times: impact on the clinical practice of heparin anticoagulation during cardiac surgery.
abstract: BACKGROUND
  The activated clotting time (ACT) is a standard monitor for heparin anticoagulation during cardiopulmonary bypass (CPB). This study determines the effect of upgrading our ACT system on our clinical practice with regards to the conduct and safety of heparin anticoagulation during cardiopulmonary bypass.
  
  
  METHODS
  We compared the intraoperative heparin doses required for all adult cardiac surgery patients (n=1240) and postoperative bleeding for a subset of primary aortocoronary bypass (CABG) surgery procedures (n=285) from cohorts before and after the change in ACT systems.
  
  
  RESULTS
  The heparin dose needed to exceed our target ACT of 480 sec for the duration of CPB was higher (45000 vs. 40000 units; p<0.0001), and the mean ACT during CPB was lower (557 vs. 618 sec; p<0.05) using the new ACT system. Furthermore, this coincided with decreased postoperative bleeding in the CABG subset (median value of 417 vs. 575 ml over 12 h; p<0.0005).
  
  
  CONCLUSIONS
  We demonstrated that the introduction of the Actalyke ACT system significantly altered our clinical practice by increasing the heparin dose required to exceed our target ACT during CPB. Prospective study to determine the effect of Actalyke ACT system monitoring on hemostasis after cardiac surgery is merited.
authors.affiliation: Department of Cardiothoracic Anesthesiology, Duke University Medical Center, Box 3094, Durham, NC 27710, USA.
authors.forename: Mathew
authors.initials: M
authors.lastname: Patteril
authors.forename: Mark
authors.initials: M
authors.lastname: Stafford-Smith
authors.forename: John G
authors.initials: JG
authors.lastname: Toffaletti
authors.forename: Barbara Phillips
authors.initials: BP
authors.lastname: Bute
authors.forename: Carmelo A
authors.initials: CA
authors.lastname: Milano
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Welsby
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use*; D002315:Cardiopulmonary Bypass; D015331:Cohort Studies; D001026:Coronary Artery Bypass; D005260:Female; D006493:Heparin / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014914:Whole Blood Coagulation Time
chemical_list: D000925:Anticoagulants; D006493:Heparin