Autotransfusion Management During and After Cardiopulmonary Bypass Alters Fibrin Degradation and Transfusion Requirements

Background: The coagulation-fibrinolytic profile during cardiopulmonary bypass (CPB) has been widely documented. However, less information is available on the possible persistence of these alterations when autotransfusion is used in management of perioperative blood loss. This study was designed to explore the influence of autotransfusion management on intravascular fibrin degradation and postoperative transfusions.

Methods: Thirty patients, undergoing elective primary isolated coronary bypass grafting, were randomly allocated either to a control group (group A; n=15) or an intervention group (group B; n=15) in which mediastinal and residual CPB blood was collected and processed by a continuous autotransfusion system before re-infusion. Intravascular fibrin degradation as indicated by D-dimer generation was measured at five specific intervals and corrected for hemodilution. In addition, chest tube drainage and need for homologous blood were monitored.

Results: D-dimer generation increased significantly during CPB in group A, from 312 to 633 vs. 291 to 356 ng/mL in group B (p = .001). The unprocessed residual blood (group A) revealed an unequivocal D-dimer elevation, 4131 +/- 1063 vs. 279 +/- 103 ng/mL for the processed residual in group B (p < .001). Consequently, in the first post-CPB period, the intravascular fibrin degradation was significantly elevated in group A compared with group B (p = .001). Twenty hours postoperatively, no significant difference in D-dimer levels was detected between both groups. However, a significant intra-group D-dimer elevation pre- vs. postoperative was noticed from 312 to 828 ng/mL in group A and from 291 to 588 ng/mL in group B (p < .01 for both). Postoperative chest tube drainage was higher in the patients from group A, which also had the highest postoperative D-dimer levels. Patients in group A perceived a higher need for transfusions of red cells suspensions postoperatively.

Conclusion: These data clearly indicate that autotransfusion management during and after CPB suppresses early postoperative fibrin degradation.