Methods: Of 525 patients undergoing coronary artery bypass grafting, 209 were randomly divided into two groups according to the amount of bleeding (group I ≥750 ml/24 h, group II <750 ml/24 h) and were retrospectively evaluated for physical characteristics, preoperative, operative, and postoperative parameters.
Results: At the end of the first day, drainage was less than 750 ml (mean 459±131.8 ml) in 174 patients (83.3%), and 750 ml or above (mean 948±188.3 ml) in 30 patients (16.6%) (p=0.0001). Bleeding indices were 528±102.7 ml/m2 and 266.0±77.7 ml/m.2 in group I and II respectively (p=0.0001). In group I, there were five females (16.6%) and 25 males (83.3%). In group II, there were 95 females (54.5%) and 79 males (45%), the number of females in group II was significantly higher (p<0.02). There were significant differences between the two groups with respect to the mean height (1.64±0.08 m in group I, 1.59±0.09 m in group II; p<0.005) and body mass index (27.1±4.0 kg/m.2 in group I, 28.6±4.1 kg/m.2 in group II; p=0.04).
Conclusion: Severe postoperative hemorrhage is associated with significant morbidity and mortality. Preoperative risk stratification may help identify subgroups of patients who has high risk for bleeding after coronary artery bypass grafting. Further studies are needed to understand the factors relevant to less hemorrhage in patients with short height and in female subjects.