title: Relationships between antithrombin activity, anticoagulant efficacy of heparin therapy and perioperative variables in patients undergoing cardiac surgery requiring cardiopulmonary bypass.
abstract: BACKGROUND
  A study on 149 cardiopulmonary bypass (CPB) patients was performed to elucidate possible relationships between antithrombin (AT) activity and a subject's clinical profile or surgery characteristics.
  
  
  METHODS
  An initial dose (300 IU/kg) of heparin was administered before CPB. Additional boluses (100 IU/kg) were administered if the activated clotting time (ACT)≤460 s. AT activity and hematological parameters were determined preoperatively, during and after CPB, and at 12, 24, 36, and 48 hours post-intervention.
  
  
  RESULTS
  29.5% patients required an additional dose of heparin during CPB. Preoperative AT was 96.5 ± 13.9% in all but 4 patients. AT was significantly lower during CPB and upon leaving the operating room (59.7%-80.0%). A small, but significant, inverse correlation was observed between AT at the end of CPB and the patient's age, as well as between basal preoperative AT and total heparin administered.
  
  
  CONCLUSIONS
  Patient's age could be a moderate indicator of AT activity drop and low preoperative AT activity could be a sign of reduced anticoagulant efficacy of heparin during CPB.
authors.affiliation: Department of Anesthesia, Critical Care and Pain Therapy, La Ribera University Hospital, Alzira, Valencia, Spain. vmuedra@hospital-ribera.com
authors.forename: V
authors.initials: V
authors.lastname: Muedra
authors.forename: S
authors.initials: S
authors.lastname: Bonanad
authors.forename: M
authors.initials: M
authors.lastname: Gómez
authors.forename: V
authors.initials: V
authors.lastname: Villalonga
authors.forename: F
authors.initials: F
authors.lastname: Sánchez
authors.forename: J E
authors.initials: JE
authors.lastname: Llopis
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000494:pharmacology / Q000627:therapeutic use*; D000990:Antithrombin III / Q000378:metabolism; D000991:Antithrombins / Q000494:pharmacology / Q000627:therapeutic use*; D001777:Blood Coagulation / Q000187:drug effects; D001780:Blood Coagulation Tests; D006348:Cardiac Surgical Procedures / Q000379:methods; D002315:Cardiopulmonary Bypass / Q000379:methods; D005260:Female; D006493:Heparin / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D014914:Whole Blood Coagulation Time
chemical_list: D000925:Anticoagulants; D000991:Antithrombins; D000990:Antithrombin III; D006493:Heparin