Efficacy And Safety Of Unfractionated Heparin In Patients With Cardiovascular Surgery Using Cardiopulmonary Bypass

Inclusion Criteria: * Patients who agree with all aspects of the study and sign the FICT; * Patients of both sexes; * Patients over the age of 18 years; * Patients with indication for cardiac surgery requiring cardiopulmonary bypass. Exclusion Criteria: * Patients with hematological disorders that compromise the surgical outcome (eg, myeloproliferative disorders, anemia, Hb \<11.0 g / dL, platelets \<100,000 mm3); * Patients with disorders of hemostasis (INR\> 1.40) (APTTr\> 1.40); * Patients with renal impairment (creatinine\> 1.50); * Patients with deep hyperthermia; * Liver disease (AST and ALT\> 2 times that of the reference value); * Patients with a history of allergy to heparin or protamine; * Patients with a history of heparin-induced thrombocytopenia; * infection (eg endocarditis, septicemia and pneumonia); * Reoperations; * Use of antiplatelet agents (clopidogrel and ticlopidine) for less than 7 days; * Use of aspirin for less than 5 days; * Use of heparin, low molecular weight less than 24 hours; * Use of unfractionated heparin for less than 12 hours.