title: Completely heparinized cardiopulmonary bypass and reduced systemic heparin: clinical and hemostatic effects.
abstract: BACKGROUND
  When heparinized circuits are used for cardiopulmonary bypass, the amounts of heparin and protamine administered systemically can be reduced. However, it is not entirely known what effects this reduction in systemic anticoagulation has on clinical performance and on the coagulation and fibrinolytic systems.
  
  
  METHODS
  Two hundred three patients undergoing first-time elective myocardial revascularization were prospectively randomized either to a group in which a completely heparin-coated circuit was used for perfusion (group H; n = 101 patients) and in which a reduced heparin dose was given (activated clotting time, > 250 seconds) or to a control group (group C; n = 102 patients) in which an uncoated, but otherwise identical, circuit was used and in which full systemic heparinization was induced (activated clotting time, > 480 seconds). Indicators of thrombin generation, platelet activation, and fibrinolytic activity were studied in a subset of 34 patients.
  
  
  RESULTS
  The total amount of postoperative mediastinal drainage was significantly reduced in group H (median, 575 mL) compared with that in group C (median, 635 mL; p = 0.002). Two patients in group C but none in group H received homologous red blood cell transfusions (p = not significant). The loss of hemoglobin in group H was a median of 21 g/L, and this was significantly lower than the 25 g/L noted in the control group (p = 0.006). During cardiopulmonary bypass, the plasma levels of thrombin-antithrombin complex and prothrombin fragment 1.2 increased in both groups. At the end of cardiopulmonary bypass the plasma levels of these markers of thrombin formation were significantly higher in group H, although the increase was modest compared with the major increase observed 2 hours after operation in both groups. There were no significant intergroup differences in the platelet counts, the concentration of beta-thromboglobulin, or the plasma levels of fibrinogen and D-dimer. No differences in perioperative morbidity, the postoperative kidney function, or the intubation time were observed, and there were no hospital deaths.
  
  
  CONCLUSIONS
  The combination of complete heparin-coated cardiopulmonary bypass circuits and low systemic heparinization is safe for patients undergoing elective coronary artery bypass procedures and reduces the perioperative blood loss. There was no evidence of increased thrombogenicity, fibrinolytic activity, or consumption of coagulation factors. No clinical or technical side effects were observed.
authors.affiliation: Department of Cardiac Surgery, Oslo Heart Center, Rikshospitalet, Norway.
authors.forename: E
authors.initials: E
authors.lastname: Ovrum
authors.forename: E A
authors.initials: EA
authors.lastname: Holen
authors.forename: G
authors.initials: G
authors.lastname: Tangen
authors.forename: F
authors.initials: F
authors.lastname: Brosstad
authors.forename: M
authors.initials: M
authors.lastname: Abdelnoor
authors.forename: M A
authors.initials: MA
authors.lastname: Ringdal
authors.forename: R
authors.initials: R
authors.lastname: Oystese
authors.forename: R
authors.initials: R
authors.lastname: Istad
mesh_terms: D000328:Adult; D000368:Aged; D000990:Antithrombin III / Q000032:analysis; D016063:Blood Loss, Surgical / Q000517:prevention & control; D002315:Cardiopulmonary Bypass / Q000295:instrumentation / Q000379:methods*; D017558:Elective Surgical Procedures; D005260:Female; D005342:Fibrinolysis; D006487:Hemostasis; D006488:Hemostasis, Surgical / Q000379:methods*; D006493:Heparin / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization; D010447:Peptide Hydrolases / Q000032:analysis; D011446:Prospective Studies; D011479:Protamines / Q000008:administration & dosage
chemical_list: D011479:Protamines; C046193:antithrombin III-protease complex; D000990:Antithrombin III; D006493:Heparin; D010447:Peptide Hydrolases