Blood product utilisation in cardiac surgery—Findings from the ASCTS database project

Introduction: Previous studies have evaluated the risk factors for increased blood product utilisation in patients undergoing cardiac surgery [1]. Blood should be viewed as a scarce resource and it is imperative to determine factors influencing its utilisation to distribute this valuable resource properly. Aim: To investigate blood product utilisation in cardiac surgery by age, gender, procedure types, clinical status and hospitals. Methods: All patients recorded in the ASCTS database having cardiac surgery between 1 July 2001 and 31 Dec 2006 (data from 6 Victorian Public Hospitals) were reviewed. Data was analysed (Stata v9.2) using simple binary logistic regression and p-value of less than 0.05 was regarded as significant. Results: 16,000 patients underwent cardiac surgery; 42.7% received red blood cells (RBC) transfusion and 25.8% of the patients received non-red blood cells (NRBC) transfusion. Females were more likely to receive RBC transfusion compared to males (odds ratio 2.21, p < 0.001). There was no significant difference in NRBC utilisation between males and females. Patients of 70 years and over were also more likely to require packed RBC compared to the younger patients (p < 0.001). However, patients over 40 years of age were less likely to utilise NRBC products compared to less than 40 years old (p < 0.001). Surgery types including valve(s) alone, combination of valve(s) and CABG, and other procedures were more likely to use both RBC and NRBC products (p < 0.001) compared to isolated CABG. The urgency of cardiac procedure was also associated with increased postoperative blood transfusion (p < 0.001). Blood product utilisation following isolated CABG varied between hospitals as shown below: When blood products were utilised following isolated CABG, the median unit of blood product administered were 2 RBC units, 2 platelets units, 3 fresh frozen plasma units and 5 cryoprecipitate units (data collected from 1 January 2005 to 31 December 2006). Discussion and conclusion: Female sex, advanced age, emergency operations and complex procedures are important predictors of increased postoperative blood transfusion.