Prevention of Organ Dysfunction and Mortality by Monitoring the Administration of Opioids and Hypnotics in Patients at High Postoperative Risk

Inclusion Criteria: * patients affiliated to the French Social Security; * informed and signed consent to participating in the study; * planned postoperative hospitalization \> 48 hours; * patients over 75 years of age with at least one of the following postoperative risk factors: * ischemic coronary disease; * history of compensated or prior heart failure; * stroke; * significant arrhythmias: fibrillation or auricular flutter with ventricular response \> 100/minute, multiform QRS complex) or cardiac conduction abnormalities (trifascicular block, auriculoventricular block of the second or third degree); * peripheral vascular disease; * chronic obstructive pulmonary disease; * chronic respiratory failure; * renal insufficiency, defined by a creatinine \> 175 µmol.l-1 (2 mg.dl-1); * insulin therapy for diabetes; * active cancer; * chronic alcohol abuse; * dementia. * elective or emergency high-risk surgery under general anesthesia with a combination of hypnotic and opioid, and intubation or placement of a supraglottic airway control device Non inclusion criteria: * Patients who meet one or more of the preoperative following criteria will not be included: * acute heart failure or acute myocardial infarction; * complete arrhythmia due to atrial fibrillation; * acute respiratory failure or pneumonia; * septic shock; * acute stroke; * cardiac surgery; * open chest surgery; * opioid free anesthesia; * intraoperative ketamine at a dose \> 0.25 mg.kg-1; \> 0.25 mg/kg or or intravenous electric syringe * lidocaine or dexmedetomidine by continuous infusion; * refusal to participate in the study; * patient under guardianship, conservatorship, or unable to understand the study.