Preoperative coagulation studies to predict blood component usage in coronary artery bypass graft surgery

Bleeding remains a serious complication of cardiac surgery. Studies indicate that preoperative fibrinogen concentration is an independent predictor of blood loss during coronary artery bypass graft (CABG) surgery. This study evaluates whether fibrinogen concentration is a better predictor of blood usage than the prothrombin time (PT) and activated partial thromboplastin time (aPTT) tests. Patients not taking clopidogrel bisulfate who underwent CABG surgery during a 3-month period at a 350-bed community hospital were included in this prospective study. The parameters evaluated included patient’s age, preoperative coagulation test results (PT, international normalized ratio [INR], aPTT, fibrinogen), and number of blood components transfused. A probability value of less than 0.05 was deemed significant. Thirty-five patients were included in this study. Mean blood usage was 6 units. Patient’s age approached significance as a predictor of blood usage, and fibrinogen levels trended toward significance more than the other coagulation parameters. In this study, the increased age of the patient and low plasma concentrations of fibrinogen were associated with increased blood usage. Although no indicators clearly demonstrated statistical significance, the vast difference in the probability values for patients’ ages and fibrinogen levels indicated that there was a trend toward significance in blood usage for CABG patients. Further studies with larger patient populations are indicated. Immunohematology2011;27:151–153.