Opioid Free Versus Opioid Based Anaesthesia for Free Flap Reconstruction Surgery of the Breast: A Phase III Multicentric Randomized Controlled Study.

Inclusion Criteria:

1. Women aged 18 or older.
2. Patients with a French health insurance coverage (having a French social securitynumber).
3. Patient eligible for free flap reconstruction surgery of the breastunder generalanaesthesia.
4. Patient who has given written consent to participate in accordance with theregulations.
5. Having a negative blood pregnancy test for patients of childbea ring age.

Exclusion Criteria:

1. Allergy or intolerance to any of the drugs (dexmedetomidine, remifentanil, lidocaine,propofol, dexamethasone, kétamine, ketoprofen, nefopam, paracetamol, morphine,ropivacaine, droperidol, ondansetron).
2. Known history of heart failure, arrhythmias and/or ischemic heart disease and/orsevere renal insufficiency.
3. Pulse below 50bpm during anaesthesia consultation and/or under beta blocker treatment.
4. Treatment with ACEI/ARB.
5. Severe asthma.
6. Symptomatic gastric or duodenal ulcer with or without treatment.
7. Baseline systolic blood pressure < 100 mmHg.
8. Chronic preoperative pain and/or use of WHO ladder step 2 or 3 analgesicspreoperatively.
9. Patient already included in another therapeutic trial evaluating an experimentalmolecule.
10. Persons deprived of liberty or under guardianship.
11. Patients with suspected difficulties in assessing pain on a scale.
12. Inability to undergo trial medical monitoring due to geographic, social orpsychological reasons.