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 blockertreatment.

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.