Predictors of Packed Red Cell Transfusion After Isolated Primary Coronary Artery Bypass Grafting – The Experience of a Single Cardiac Center: A Prospective Observational Study

Background: Preoperative patients’ characteristics can predict the need for perioperative blood component transfusion in cardiac surgical operations. The aim of this prospective observational study is to identify perioperative patient characteristics predicting the need for allogeneic packed red blood cell (PRBC) transfusion in isolated primary coronary artery bypass grafting (CABG) operations.

Methods: 105 patients undergoing isolated, first-time CABG were reviewed for their preoperative variables and followed for intraoperative and postoperative data. Patients were 97 males and 8 females, with mean age 58.28 +/- 10.97 years. Regression logistic analysis was used for identifying the strongest perioperative predictors of PRBC transfusion.

Results: PRBC transfusion was used in 71 patients (67.6%); 35 patients (33.3%) needed > 2 units and 14 (13.3%) of these needed > 4 units. Univariate analysis identified female gender, age > 65 years, body weight < 70 Kg, BSA < 1.75 m2, BMI < 25, preoperative hemoglobin < 13 gm/dL, preoperative hematocrit < 40%, serum creatinine > 100 mmol/L, Euro SCORE (standard / logistic) > 2, use of CPB, radial artery use, higher number of distal anastomoses, and postoperative chest tube drainage > 1000 mL as significant predictors. The strongest predictors using multivariate analysis were CPB use, hematocrit, body weight, and serum creatinine.

Conclusion: The predictors of PRBC transfusion after primary isolated CABG are use of CPB, hematocrit < 40%, weight < 70 Kg, and serum creatinine > 100 mmol/L. This leads to better utilization of blood bank resources and cost-efficient targeted use of expensive blood conservation modalities.