Fibrinolysis during cardiopulmonary bypass detected with thromboelastography

Background

Fibrinolysis is a common haemostatic abnormality during cardiopulmonary bypass (CPB). Thromboelastography (TEG) is a good method to detect both types of fibrinolysis.

Methods

Four hundred and ninety-nine patients during mild hypothermic CPB and elective surgery were monitored with TEG (first – after the induction, second – after rewarming, third and fourth – at the end of surgery native and heparinase). No prophylactic antifibrinolytics were used. The data of the study group were compared with a control group of 475 patients monitored only with laboratory tests (fibrin degradation products (FDP) and D-dimers). Peroperative and 24 hour postoperative bleeding, number of transfusions, aprotinin therapy and reexploration were recorded. Correlations between the presence of fibrinolysis and blood loss and transfusion therapy and between aprotinin administration and blood loss and number of transfusions were evaluated.

Results

The frequency of fibrinolysis measured with TEG: before surgery – primary 3.2%/secondary 3.4%; during CPB – 18.8%/0.6%; after surgery – 7%/1.4% (native), 5.6%/0.6% (heparinase). Positivity of fibrinolysis detected with laboratory tests was 100%. The TEG parameter of fibrinolysis (LY30) was significantly increased during CPB. The frequency of aprotinin administration was 12% TEG, 10.7% control. No correlation between positivity of fibrinolysis and peroperative/postoperative blood loss and red blood cells (RBC) and fresh frozen plasma (FFP) transfusions were recorded. No correlation between aprotinin administration and peroperative/postoperative blood loss and RBC transfusion were recorded. Positive correlation between aprotinin administration and FFP transfusion were recorded

Conclusion

Fibrinolysis was usually not associated with serious bleeding. There was no positive effect of aprotinin to reduce bleeding or transfusion therapy. FDP and D-dimers are not useful to detect fibrinolysis in cardiac surgery.