RESUMO
OBJECTIVE: To evaluate the risk factors related to bleeding in patients subjected to cardiac surgery using an extracorporeal circulation pump. MATERIAL AND METHODS: A study of cases and controls was designed performed in adults, matched by age and gender with indication of elective cardiac surgery using an extracorporeal circulation pump. Those patients with hepatic failure or blood coagulation disorders were excluded. Results were analyzed by Student t test, chi-square, and logistic regression analysis, considering p values significant at <0.05. RESULTS: The patients with functional class III or IV of the CCS presented more bleeding (p = 0.006), although there were no differences when comparing the ejection fraction in both. Obesity, dyslipidemia, and arterial hypertension were identified as risk factors. The coronary artery bypass graft, multivessels bypass surgery, and prolonged surgical times are associated to the complication (p < 0.05). According to the discriminant function analysis, the cardiopulmonary derivation time, weight, aortic clamp time, and heparin doses are the factors that better discriminate the possibility of hemorrhage. CONCLUSIONS: Heavy bleeding is related to ischemic patients, longer cardiac surgery time, overweight, and heparin doses during surgery.