Strategies to reduce hemostatic activation during cardiopulmonary bypass.

Introduction: We evaluated whether a modified protocol for cardiopulmonary bypass (CPB) could reduced the systemic hemostatic activation associated with this procedure.

Materials And Methods: The in vivo rates of thrombin, fibrin, plasmin and D-dimer generation were determined in each subject during CPB using measured levels of hemostatic factors combined with a computer model of the cardiovascular and hemostatic systems. A standard CPB group using uncoated circuits, standard heparin levels and direct shed blood reinfusion (n=9) was compared to a modified CPB group using heparin-coated circuits, shed blood collection, washing and reinfusion post-operatively, lower heparin levels and epsilon-amino-caproic acid (n=10).

Plasmin generation and D-dimer formation during cardiopulmonary bypass.

The purpose of this study was to estimate the in vivo rates of plasmin and D-dimer generation for comparison with the rate of fibrin formation during cardiopulmonary bypass (CPB), a procedure known to induce a hyperfibrinolytic state. Plasmin and D-dimer generation rates were based on measured levels of antiplasmin, plasmin-antiplasmin complex and D-dimer obtained before, during and after CPB from nine males, combined with a computer model of each patient's vascular system that continuously accounted for secretion, clearance, hemodilution, blood loss and transfusion. At baseline the average plasmin and D-dimer generation rates were 0.

Effects of surgical trauma and cardiopulmonary bypass on active thrombin concentrations and the rate of thrombin inhibition in vivo.

The in vivo concentration of active thrombin and the second-order rate constant for the inhibition of thrombin by antithrombin (k(inh)) were estimated in patients undergoing cardiopulmonary bypass (CPB) based on measured levels of hemostatic markers in combination with a computer model of the patient's hemostatic and vascular systems. At baseline k(inh) = 0.6 +/- 0.

Secretion of tissue plasminogen activator and plasminogen activator inhibitor 1 during cardiopulmonary bypass.

Introduction: Cardiopulmonary bypass (CPB) is associated with elevated tissue plasminogen activator (t-PA) levels during CPB and increased plasminogen activator inhibitor 1 (PAI-1) levels post-operatively. The goal of this study was to estimate the rate of t-PA and PAI-1 secretion in vivo, before, during and after CPB.

Materials And Methods: Estimated rates of t-PA and PAI-1 secretion were based on measured levels of active and total t-PA, and active and total PAI-1, obtained before, during and after CPB from nine males, combined with a computer model of each patient's vascular system that continuously accounted for secretion, clearance, hemodilution, blood loss and transfusion.

Estimating the rate of thrombin and fibrin generation in vivo during cardiopulmonary bypass.

Our objective was to estimate the in vivo rates of thrombin and fibrin generation to better understand how coagulation is regulated. Studied were 9 males undergoing cardiopulmonary bypass (CPB). The rates of thrombin, total fibrin, and soluble fibrin generation in vivo were based on measured levels of prothrombin activation peptide F1.