Hydroxyethylstarch and gelatin solutions impair blood coagulation after cardiac surgery: a prospective randomized trial.

BACKGROUND Colloids are often used after cardiac surgery as intravascular volume replacement therapy. Cardiac surgical patients have an increased risk of bleeding. Both hydroxyethylstarch (HES) and gelatin solutions impair haemostasis. We examined the impact and dose effect on coagulation of HES 130/0.4, gelatin, or Ringer's acetate solutions after cardiac surgery. METHODS Forty-five patients received three boluses (each 7 ml kg(-1)) of either 6% HES 130/0.4, 4% gelatin, or Ringer's acetate solution after elective cardiac surgery. The infusion of study solution was continued in the dose 7 ml kg(-1) over the following 12 h. The total dose of study solution was 28 ml kg(-1). Hypovolaemia was treated with Ringer's acetate. Modified thromboelastometry was performed to detect coagulation disorders. RESULTS Clot formation time was prolonged and clot strength decreased after infusion of 7, 14, and 21 ml kg(-1) of either colloid compared with the Ringer's acetate group. After infusion of 14 and 21 ml kg(-1) of Ringer's acetate, clot strength was slightly, but significantly, increased. On the first postoperative morning, clot strength was still decreased in the gelatin group in comparison with the Ringer's acetate group. Neither HES nor gelatin induced fibrinolysis. Chest tube drainage was comparable between all groups. CONCLUSIONS Even a small dose of HES 130/0.4 or gelatin impaired clot strength after cardiac surgery in a dose-dependent fashion, but neither colloid increased blood loss.