Inclusion Criteria:  Patients having planned cardiac surgery under cardiopulmonary bypass, with at least one coronary artery bypass grafting and removal of at least one internal mammary artery; possible association with aortic valve replacement Patient having read and understood the information letter and signed the consent form For women : of childbearing age, need to confirm the absence of an active pregnancy by a negative blood pregnancy test within 48 hours prior to inclusion / menopausal (amenorrhea not medically induced for at least 12 months before the inclusion visit) Patient affiliated to a social security scheme  Exclusion Criteria:  Preoperative treatment with morphine or its derivatives (including tramadol) in the 15 days preceding the inclusion visit Pre-existing high-degree conduction disorder not paired Oxygen therapy prior to inclusion Heart failure with LVEF <40% BMI ≥ 35 Myocardial suffering in the 5 days preceding inclusion Patient in shock Known adrenal insufficiency and / or long-term systemic corticosteroid treatment (equivalent to hydrocortisone hemisuccinate ≥ 20 mg / day) Mixed surgery other than aortic valve Long-term non-invasive ventilation (including for obstructive sleep apnea syndrome) Any antecedent or active practice (s) of drug addiction; Contraindication to one of the experimental and / or non-experimental treatments: dexmedetomidine, lidocaine, dexamethasone, ketamine, remifentanil or morphine Acute cerebrovascular pathology, Severe hepatic insufficiency (factor V level <50%), Pre-existing cognitive disorders, Patient for whom the CAM-ICU questionnaire cannot be carried out (deaf patients for example), Pregnant or parturient or breastfeeding woman Person deprived of liberty by an administrative or judicial decision or person placed under judicial protection / under guardianship or guardianship Patient participating in another drug trial or having participated in another drug trial within 1 month before randomization