title: Retransfusion of pericardial blood does not trigger systemic coagulation during cardiopulmonary bypass.
abstract: OBJECTIVE
  During cardiopulmonary bypass (CPB), systemic coagulation is believed to become activated by blood contact with the extracorporeal circuit and by retransfusion of pericardial blood. To which extent retransfusion activates systemic coagulation, however, is unknown. We investigated to which extent retransfusion of pericardial blood triggers systemic coagulation during CPB.
  
  
  METHODS
  Thirteen patients undergoing elective coronary artery bypass grafting surgery were included. Pericardial blood was retransfused into nine patients and retained in four patients. Systemic samples were collected before, during and after CPB, and pericardial samples before retransfusion. Levels of prothrombin fragment F(1+2) (ELISA), microparticles (flow cytometry) and non-cell bound (soluble) tissue factor (sTF; ELISA) were determined.
  
  
  RESULTS
  Compared to systemic blood, pericardial blood contained elevated levels of F(1+2), microparticles and sTF. During CPB, systemic levels of F(1+2) increased from 0.28 (0.25-0.37; median, interquartile range) to 1.10 (0.49-1.55) nmol/l (p=0.001). This observed increase was similar to the estimated (calculated) increase (p=0.424), and differed significantly between retransfused and non-retransfused patients (1.12 nmol/l vs 0.02 nmol/l, p=0.001). Also, the observed systemic increases of platelet- and erythrocyte-derived microparticles and sTF were in line with predicted increases (p=0.868, p=0.778 and p=0.205, respectively). Before neutralization of heparin, microparticles and other coagulant phospholipids decreased from 464 microg/ml (287-701) to 163 microg/ml (121-389) in retransfused patients (p=0.001), indicating rapid clearance after retransfusion.
  
  
  CONCLUSIONS
  Retransfusion of pericardial blood does not activate systemic coagulation under heparinization. The observed increases in systemic levels of F(1+2), microparticles and sTF during CPB are explained by dilution of retransfused pericardial blood.
authors.affiliation: Department of Cardio-thoracic Surgery, Academic Medical Center of the University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. J.M.vandenGoor@amc.uva.nl
authors.forename: Jeanette M
authors.initials: JM
authors.lastname: van den Goor
authors.forename: Rienk
authors.initials: R
authors.lastname: Nieuwland
authors.forename: Peter M
authors.initials: PM
authors.lastname: Rutten
authors.forename: Jan G
authors.initials: JG
authors.lastname: Tijssen
authors.forename: Chi
authors.initials: C
authors.lastname: Hau
authors.forename: Augueste
authors.initials: A
authors.lastname: Sturk
authors.forename: León
authors.initials: L
authors.lastname: Eijsman
authors.forename: Bas A
authors.initials: BA
authors.lastname: de Mol
mesh_terms: D000368:Aged; D001777:Blood Coagulation / Q000502:physiology*; D001792:Blood Platelets / Q000737:chemistry; D001804:Blood Transfusion, Autologous / Q000009:adverse effects* / Q000379:methods; D002315:Cardiopulmonary Bypass / Q000379:methods*; D003326:Coronary Circulation / Q000502:physiology*; D004912:Erythrocytes / Q000737:chemistry; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood; D010496:Pericardium / Q000503:physiopathology*; D010743:Phospholipids / Q000097:blood; D011446:Prospective Studies; D011516:Prothrombin; D012995:Solubility; D013925:Thromboplastin / Q000032:analysis
chemical_list: D010446:Peptide Fragments; D010743:Phospholipids; C045879:prothrombin fragment 1.2; D011516:Prothrombin; D013925:Thromboplastin