Abstract 124: Can High-Quality Interventional Trials be Performed in Cardiac Surgery Patients With Excessive Bleeding Despite Conventional Blood Transfusion Therapy?
Introduction: Design of interventional studies in patients with excessive bleeding despite “conventional” transfusion therapy is hampered by questions regarding study population and compliance with treatment protocols. We designed a feasibility study in patients undergoing complex cardiac surgery using a blood management protocol. Our hypotheses were (1) that limiting enrollees to those with complex surgical procedures would lead to a higher incidence of treatment failures than that reported in the literature and (2) good compliance with a standardized intraoperative and postoperative protocol is achievable.
Methods: Patients scheduled for complex cardiac surgery were studied using a multidisciplinary blood management protocol that had 5 components (treatments, Hemostasis Score, blood loss, blood transfusion and laboratory samples) that were graded for compliance: >90% was considered “good.” Conventional replacement therapy was considered a “failure” if excessive bleeding persisted despite transfusion with the standardized protocol of 2U single-donor apheresis platelets, 6U fresh frozen plasma and 10U cryoprecipitate.
Results and Conclusions: Of the 405 patients scheduled for surgery from March 2008 to April 2009, 135 (32%) were predicted to be at increased risk for excessive bleeding. Of these, 49 patients were approached for consent and 43 were enrolled in the study. Twenty-seven (63%) had excessive bleeding (Hemostasis score ≥3) after heparin reversal that persisted despite standardized blood management in six (14%) subjects. Compliance was assessed for 499 required protocol tasks and was considered “good” in all the categories tested except required laboratory samples (74%). RBC transfusion was higher in those who failed the protocol (14U [IQR 13U–16U]; n=6) vs. responders (4U [IQR 3U – 9U]; n=21; p<0.0001). In conclusion, this feasibility study suggests that high-quality trials can be conducted using a blood management protocol in patients with excessive bleeding. Treatment failures were higher than that reported in the literature (14% vs. 2%) yet required seven patients to be consented in order to identify one treatment failure (7:1). Centers that perform a high volume of complex cardiac cases will be required for these trials.
- © 2010 by American Heart Association, Inc.