Prospective Evaluation of a Blood Transfusion Protocol for Patients Undergoing Cardiac Operations

Abstract

The Society of Thoracic Surgeons clinical practice guidelines recommend the creation of an interdisciplinary blood management team to implement protocols for improved blood transfusion practices. We report our center's prospective evaluation of a blood transfusion protocol. An interdisciplinary blood management team developed protocols for transfusion of packed red blood cells, fresh frozen plasma, platelets, and cryoprecipitate. The protocols were prospectively evaluated by tracking transfusions administered to consecutive patients undergoing cardiac operations, and the primary outcome of interest was the mean number of adjusted units of blood product transfused per patient. Protocol implementation phases were separated by washout phases to control for a potential Hawthorne effect associated with protocol implementation. Protocol compliance was also assessed. A total of 1441 patients underwent cardiac operations during the 16-month study period. Although there was no statistically significant reduction in transfusions with an unadjusted analysis, there was a significant trend toward a reduction of the mean adjusted total units transfused per patient over the course of the study period (P < .001). The mean adjusted total units transfused per patient were significantly less during the second washout phase (2.8 units; 95% confidence interval [CI], 2.3-3.3) and second protocol phase (2.8 units; 95% CI, 2.32-3.27) compared with the initial baseline survey phase (3.6 units, 95% CI, 3.1-4.1; P < .05 for both comparisons). Only 55.2% of all units were transfused in compliance to the implemented protocols: platelets, 46.8%; cryoprecipitate, 32.1%; packed red blood cells, 60.7%; and fresh frozen plasma, 53.6%. During a prospective evaluation of blood transfusion protocols, a risk-adjusted analysis demonstrated a reduction in transfusions despite poor protocol compliance.