The Comparability of Bispectral Index and Neurosense During Anesthesia

Inclusion Criteria: * Patients requiring either intravenous anesthesia or balanced anesthesia (including sevoflurane) Exclusion Criteria: * Pregnant women, * Allergy to propofol, remifentanil, morphine, muscle relaxant, or to a component, * Hypersensibility to sufentanil, remifentanil or to a derivate of fentanyl, * History of neurological disorder or central brain lesion, of muscle disease, * Patient carrying a pacemaker, * Patients receiving a psychotropic treatment or a morphine agonist-antagonist, * Alcoholic patients and patients taking opiates, * Surgery with extracorporeal circulation, * Surgical position incompatible with an adequate positioning of the probe.