416 Improved surgical outcomes with the universal use of individualized heparin and protamine management system for pediatric cardiac surgery with cardiopulmonary bypass

Abstract

In a recent clinical trial we established that the use of the Hemostatic Management System (HMS) with a pediatric-specific protocol, for the individualized management of heparin and protamine dosing during cardiac surgeries performed on patients <1 year of age resulted in enhanced anticoagulation and improved surgical outcomes. Based on the results of this study the HMS system was thereafter employed for all cardiac surgeries. We sought to determine whether the universal use of the HMS was associated improved program-wide post-operative outcomes. A total of 622 pediatric cardiac surgeries performed between April 2009 and August 2010 using the HMS were compared to 1,542 surgeries performed between July 2004 and December 2007, using standard weight-based heparin dosing using the activated clotting time for monitoring (HMS was evaluated/deployed between those 2 periods). Outcomes between the 2 periods were compared with adjustments for multiple patients and surgical characteristics in multivariable regression models. Patients and surgical characteristics between the pre-HMS and post-HMS era were similar. The HMS failed to achieve sufficiently high heparin blood concentration after the initial heparin bolus in 52% of cases and required an additional heparin bolus prior to bypass initiation. Most patients (361, 58%) received additional heparin during the surgery, despite normal activated clotting time (>400s). Patients in the post-HMS era required significantly lower amount of allogeneic red blood cell (87ml/kg vs. 118 ml/kg, P < 0.001) and platelets (8ml/kg vs. 14ml/kg, P < 0.001). Use of recombinant factor VIIa in post-operative period was less likely in the post-HMS era (1.1% vs. 3.5%, P = 0.03). Intubation time (9 vs. 27 hours, P < 0.001), intensive care unit stay (2 vs. 3 days, P = 0.009) and hospital stay (6.3 vs. 8.0 days, P = 0.02) were all shorter in the post-HMS period. Failure of the HMS system to achieve sufficient blood heparin concentration after the initial dose shows that further refinements in the pediatric protocol are necessary. Even considering this, the use of the HMS system for all pediatric cardiac surgeries was associated with system-wide improvement in post-surgical outcomes. Although the effect cannot be entirely ascribed to the use of the HMS because of additional concurrent changes in surgical and post-operative protocols, the reduction of allogeneic blood transfusions and bleeding-related complications suggest that the HMS system was a contributor to the improved surgical outcomes observed between the 2 periods.