Cardiac Index and General Anesthesia Without Opioid.

Inclusion Criteria: * Eligible patients for scheduled total hip arthroplasty with general anesthesia. * Patients with an American Society of Anesthesiologists (ASA) score between 1 and 3 * Patient who has received appropriate information and has provided informed consent. * Patient with French social security system. Exclusion Criteria: * Patients eligible to rapid sequence intubation. * Patients with medical contraindication to the use of OFA : allergy to one of the drug used in the protocol, spontaneous bradycardia under 40bpm or atrioventricular block. * Patients with a medical condition that could alter measurement of cardiac index by NICCOMO™: acute pulmonary oedema, severe valvular heart disease, pulmonary hypertension, atrial fibrillation. * Patients who cannot give their informed consent. * Patients pregnant or breastfeeding. * Patients odler than 90 years old or with a weigh superior at 150kg.