title: The treatment of heparin resistance with Antithrombin III in cardiac surgery.
abstract: OBJECTIVE
  To report three patients who developed heparin resistance during cardiac surgery which was successfully managed with 1000 U Antithrombin III (AT III).
  
  
  METHODS
  We observed heparin resistance prior to cardiopulmonary bypass (CPB) in one patient and during the CPB in two patients. In the first patient who was scheduled for mitral valve replacement, although heparin was administered sequentially up to 500 U x kg(-1) prior the CPB, the ACT value was 354 sec. After 1,000 U ATIII were administered the ACT was 395 sec and CPB was initiated. The ACT remained between 496 and 599 sec throughout CPB and a total of 260 mg protamine sulfate was given. In the other two patients following 300 U x kg(-1) heparin, the ACT was up to 400 sec and CPB was initiated. During CPB, ACT were decreased 360 sec and 295 sec in patients II and III respectively. Although heparin was added 1,500 U, ACT increased to > or = 400 sec could not be achieved. In the second patient ATIII activity was found 10%. After the administration of 1,000 U ATIII, ATIII activity was found to be 67% 40 min later and ACT were increased up to 400 sec. There was no thrombosis within the extracorporeal circuit, additional heparin was not required, less protamine was administered (< or = 3 mg x kg(-1)) and no excessive postoperative bleeding was observed in all patients.
  
  
  CONCLUSIONS
  We recommend that AT III supplementation should be considered to manage heparin resistance prior or during CPB in patients undergoing open heart surgery.
authors.affiliation: Department of Anaesthesiology and Reanimation, Hacettepe University, Faculty of Medicine, Ankara, Turkey. ok05-k@tr-net.net.tr
authors.forename: M
authors.initials: M
authors.lastname: Kanbak
mesh_terms: D000328:Adult; D000925:Anticoagulants / Q000627:therapeutic use*; D000990:Antithrombin III / Q000627:therapeutic use*; D001021:Aortic Valve / Q000601:surgery; D001777:Blood Coagulation / Q000187:drug effects*; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass; D004351:Drug Resistance; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006493:Heparin / Q000627:therapeutic use*; D006494:Heparin Antagonists / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery; D011479:Protamines / Q000627:therapeutic use; D015842:Serine Proteinase Inhibitors / Q000627:therapeutic use*; D013997:Time Factors
chemical_list: D000925:Anticoagulants; D006494:Heparin Antagonists; D011479:Protamines; D015842:Serine Proteinase Inhibitors; D000990:Antithrombin III; D006493:Heparin