RESULTS
Fifty patients meeting the inclusion criteria were enrolled in the study (mean age 63.08 ± 10.77 years, 78% male). Demographic features and patients characteristics are listed in Table 1 . Mean duration of operation was 290.70 ± 53.02 minutes and median aortic cross clamp time was 65.5 (56 - 76) minutes. Median intraoperative UF heparin dose was 45 (45 - 50) x 103 units. Overall, 38% of the subjects had received erythrocyte suspension and 18% had received fresh frozen plasma during the operation. Postoperative drainage volumes at the 2nd, 4th, 6th, 12th, and 24th hours were 100 (50 - 200) mL, 200 (150 - 300) mL, 300 (200 - 400) mL, 450 (350 - 550) mL, and 525 (400 - 700) mL, respectively. With regard to the distribution of postoperative transfusions, it was found that 26% of the study subjects received 1 unit of erythrocyte suspension, 26% received 2 units of erythrocyte suspension, and 10 % received 3 units of erythrocyte suspension. For fresh frozen plasma, the distributions were: 1 unit in 12%, 2 units in 28%, and 3 units in 14% of the study subjects. Median length of hospital stay was 6 (6 - 8) days. In-hospital mortality occurred in 2% of the patients (Table 2) .
The change in blood test results throughout the hospitalization are presented in Table 3. A significant increase in IPC and IPF values was observed at the postoperative first day compared to baseline values. Preoperative IPC and IPF were negatively correlated with intraoperative blood transfusion (p=0.017, and p=0.049, respectively). Duration of the operation, preoperative hemoglobin and hematocrit levels were significantly correlated with the length of hospital stay(Table 4) .
Multiple linear regression analysis was performed to determine significant associates of the amount of blood components used. We found that longer duration of operation (p=0.002) and higher preoperative MPV values (p=0.031) were associated with higher numbers of blood components used (Table 5) . Other variables included in the model, age (p=0.099), gender (p=0.245), surgery (p=0.859), aortic cross-clamp duration (p=0.744), intraoperative heparin (p=0.538), preoperative red blood cell count (p=0.268), preoperative hemoglobin (p=0.162), preoperative hematocrit (p=0.295), preoperative platelet (p=0.936), preoperative IPF (p=0.376), preoperative IPC (p=0.315) and preoperative INR (p=0.903) were found to be non-significant.