The night before surgery, patients are premedicated with midazolam 7.5 mg per os. Upon arrival in the operating room, monitoring devices (ECG, non-invasive arterial pressure, capnography, pulse oximetry) and a bispectral index (BIS) monitor are established. An intravenous line is secured, general intravenous anesthesia is induced with target infusion remifentanil and propofol. Cisatracurium besylate (0.5 mg/kg) is given to facilitate tracheal intubation and controlled ventilation is adjusted to maintain normocapnia with a 50% oxygen fraction administered. Then, the study medications are administered in bolus during 20 minutes, followed by continuous infusion of the specific solution, according to the study group to which the patient belonged, as described before.