Use of laboratory testing for prediction of postoperative bleeding volume in cardiovascular surgery.

ABSTRACT

BACKGROUND: Coagulopathy and following massive bleeding are complications of cardiovascular surgery, particularly occurring after procedures requiring prolonged cardiopulmonary bypass (CPB). Reliable and rapid tests for coagulopathy are desirable for guiding transfusion. Measuring multiple coagulation parameters may prove useful. The purpose of this study is to determine the laboratory parameters predicting massive bleeding. METHODS: In a prospectively collected cohort of 48 patients undergoing cardiovascular surgery, markers of coagulation and fibrinolysis were measured using automated analyzer and their correlations with bleeding volume were determined. RESULTS: Operation time was 318 (107-654) min. CPB time was 181 (58-501) min. Bleeding volume during surgery was 2269 (174-10,607) ml. Number of transfusion units during surgery were packed red blood cells 12 (0-30) units, fresh frozen plasma 12 (0-44) units, platelets 20 (0-60) units and intraoperative autologous blood collection 669 (0-4439) ml. Post-surgery activities of coagulation factors II (FII), FV, FVII, FVIII, FIX, FX, FXI and FXII were decreased. Values of fibrinogen, antithrombin, α2 plasmin inhibitor (α2PI) and FXIII were also decreased. Values of thrombin-antithrombin complex (TAT) were increased. Values of FII, FIX, FXI and α2PI before surgery were negatively correlated with bleeding volume (FII, r = - 0.506 FIX, r = - 0.504 FXI, r = - 0.580; α2PI, r = - 0.418). Level of FIX after surgery was negatively correlated with bleeding volume (r = - 0.445) and level of TAT after surgery was positively correlated with bleeding volume (r = 0.443). CONCLUSIONS: These results suggest that several clinical and routine laboratory parameters of coagulation were individually associated with bleeding volume during cardiovascular surgery. Determining the patterns of coagulopathy may potentially help guide transfusion during cardiovascular surgery.