Use of Closed-loop Anesthesia in Pediatric Patients

Inclusion Criteria: * class ASA I, II or III * general anesthesia scheduled to last more than one hour * intraoperative hemorrhage planned to be less than 15% of the blood volume Exclusion Criteria: * Combined general and regional anesthesia, * Patients with a pacemaker or scheduled for a cardiac or brain surgical procedure, * History of a neurological or a psychiatric disorder, or central brain lesion, * Patients receiving a psychotropic treatment or a a morphine agonist-antagonist, * Allergy to latex, propofol, remifentanil, morphine, muscle relaxant, or to a component, * Hypersensibility to remifentanil or to a derivate of fentanyl, * Scheduled postoperative ventilation or sedation.