Hemostatic effects of a dextran-based priming solution for cardiopulmonary bypass: A secondary analysis of a randomized clinical trial.

INTRODUCTION: Intravascular fluids administered to patients may influence hemostasis. In patients undergoing cardiac surgery with cardiopulmonary bypass, the heart-lung machine is primed with 1300 ml of fluid. We assessed postoperative coagulation and platelet function in patients randomized to two different priming solutions, one colloid-based (dextran 40) and one crystalloid-based.

MATERIALS AND METHODS: Eighty-four elective cardiac surgery patients were randomized to either a dextran-based prime or Ringer's acetate with added mannitol. Blood samples were collected before, and 2 and 24 h after cardiopulmonary bypass. Coagulation was assessed by standard coagulation tests and rotational thromboelastometry. Platelet function was assessed with impedance aggregometry. Bleeding volumes and transfusion requirements were recorded.

RESULTS: Comparing the groups 2 h after bypass, the dextran group showed lower hemoglobin concentration, hematocrit, platelet count, and fibrinogen concentration, and higher INR and aPTT, as well as longer clot formation time (+41 ± 21 % vs. +8 ± 18 %, p < 0.001) and a larger reduction in fibrinogen-dependent clot strength (-37 ± 12 % vs. -7 ± 20 %, p < 0.001). Adenosine diphosphate-dependent platelet activation was reduced in the dextran group but not in the crystalloid group 2 h after bypass (-14 ± 29 % vs. -1 ± 41 %, p = 0.041). No significant between-group differences in hemostatic variables remained after 24 h, and no significant differences in perioperative bleeding volumes, re-explorations for bleeding, or transfusion rates were observed.

CONCLUSIONS: Compared to a crystalloid solution, a dextran-based prime had measurable negative impact on hemostatic variables but no detectable increase in bleeding volume or transfusion requirements in cardiac surgery patients.