Anesthetic technique The techniques used for anesthesia, surgery and cardiopulmonary bypass follow the practice routine of the institution. Patients will receive 5 mg of Midazolam IM as Preanesthetic medication 30 minutes before induction of anesthesia. Routine monitoring will include electrocardiogram five derivations and pulse oximetry. Before induction of anesthesia, a radial artery catheter will be inserted along with the monitoring BIS (BIS Vista ™; Covidien). Anesthesia is induced with 0.3 µg/kg sufentanil and 0.2-0.3 mg/kg etomidate based on the physical condition of the patient. Muscle relaxation is obtained using 0.1 mg/kg pancuronium. After tracheal intubation, a central venous catheter is inserted into the subclavian vein. The temperature of the patient will be monitored by a thermometer in the esophagus. Anesthesia will be maintained with bolus Sufentanil according to the patient's need and Sevoflurane to 1 MAC expired fraction. Mechanical ventilation will be maintained at Drager apparatus (Primus model) with the following parameters: tidal volume of 8 ml/kg, respiratory rate 12 ipm, PEEP of 5 cm H2O in ventilation mode controlled volume. Before the insertion of the aortic cannula, patients will be anti-coagulated with heparin (400 units / kg) and subjected to a muscular relaxation with 0.05 mg/kg pancuronium.