title: Hemostatic alterations during coronary artery bypass grafting.
abstract: BACKGROUND
  The origination of blood loss after cardiac surgery is not fully explained, but is related to operation trauma and use of cardiopulmonary bypass (CPB). However, the extent of their contribution is incompletely known and might differ between distinct operation procedures.
  
  
  METHODS
  Three groups of CABG procedures were studied: 1) off-pump coronary artery bypass surgery (OPCAB, n=11) without CPB, 2) CABG with use of CPB (CABG, n=11) and 3) CABG with use of CPB combined with aortic valve replacement (AVR, n=11). Activation of coagulation and fibrinolysis was measured at various time points by flow cytometry, platelet aggregometry, thrombelastography, the Nijmegen Hemostasis Assay, prothrombin fragment 1+2 and tissue plasminogen activator.
  
  
  CONCLUSIONS
  The use of CPB during cardiac surgery decreased platelet counts, clot strength, fibrinogen, hematocrit and albumin concentrations during the procedure. No perioperative platelet activation was observed and functional (collagen induced) platelet aggregation was transiently impaired, but recovered after surgery in all groups. Patients operated with use of CPB showed increased tissue plasminogen activator concentrations after reperfusion followed by minor and transient fibrinolysis. After all types of surgery coagulation parameters and platelet aggregation showed a rebound above preoperative levels. To conclude, no evident platelet activation, dysfunction or consumption was demonstrated. In patients using tranexamic acid the most prominent factor impairing hemostasis after CABG surgery was hemodilution associated with CPB.
authors.affiliation: Dept. of Cardiothoracic Surgery, Leiden University Medical Center (LUMC), The Netherlands. Electronic address: c.l.i.gielen@lumc.nl.
authors.forename: Chantal L I
authors.initials: CLI
authors.lastname: Gielen
authors.affiliation: Sanquin Blood Bank Leiden, Leiden, The Netherlands.
authors.forename: Anneke
authors.initials: A
authors.lastname: Brand
authors.affiliation: Laboratory of Hematology, Dept. of Laboratory Medicine, Radboudumc, Nijmegen, The Netherlands.
authors.forename: Waander L
authors.initials: WL
authors.lastname: van Heerde
authors.affiliation: Dept. of Medical Statistics, LUMC, Leiden, The Netherlands.
authors.forename: Theo
authors.initials: T
authors.lastname: Stijnen
authors.affiliation: Dept. of Cardiothoracic Surgery, Leiden University Medical Center (LUMC), The Netherlands.
authors.forename: Robert J M
authors.initials: RJM
authors.lastname: Klautz
authors.affiliation: Dept. of Thrombosis and Hemostasis, LUMC, Leiden, The Netherlands.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Eikenboom
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001777:Blood Coagulation; D001780:Blood Coagulation Tests; D001026:Coronary Artery Bypass / Q000379:methods*; D047549:Coronary Artery Bypass, Off-Pump / Q000379:methods; D005260:Female; D006400:Hematocrit; D006487:Hemostasis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation; D010976:Platelet Count
keywords: Bleeding, bleeding control; Blood coagulation; Cardiopulmonary bypass; Surgery, complications