OBJECTIVE: To determine predictors of postoperative bleeding after cardiac surgery, in order to focus on preventive measures for high-risk populations. METHODS: From October 2001 to March 2002, 411 consecutive adult cardiac surgery patients were prospectively studied, with the exception of those submitted to heart transplantation. In order to determine risk factors for postoperative bleeding, 20 preoperative, 17 operative and six postoperative variables were analyzed using univariate methods and multiple linear regression. RESULTS: Operative procedures included coronary artery bypass grafting in 227 (55.2%) patients, valvar operations in 198 (48.2%), aortic surgery in 25 (6.1%) and combined procedures in 60 (14.6%). Cardiopulmonary bypass was used in 335 (81.5%) patients and anti-fibrinolysis agents in 148 (36%). The thirty-day mortality was 5.6% (23 patients). Mean 24-hour postoperative blood loss was 610 ± 500 ml (range 10-4900). Re-exploration for bleeding was required in 15 (3.7%) patients. Independent predictors of postoperative bleeding were emergency operations (p=0.049), postoperative metabolic acidosis (p=0.001), preoperative thrombocytopenia (p=0.034) and prolonged cardiopulmonary bypass (p=0.021). CCONCLUSIONS: When possible, preoperative stabilization and correction of coagulation disturbances should be achieved in patients requiring urgent or emergent surgery and in those with thrombocytopenias. The duration of cardiopulmonary bypass should be minimized as long as this is practical. Postoperative metabolic acidosis must be actively corrected, especially the main determining cause.
Hemorrhage; Blood loss, surgical; Blood coagulation disorders; Risk factors; Cardiac surgical procedures; Postoperative complications; Multivariate analysis
