Impact of Pregabalin in Chronic Users vs. a Perioperative Limited Prescription on Oxycodone Requirement

Postoperative Oxycodone Consumption After Spinal Surgery in Pregabalin-treated Patients Compared to a 48-h Perioperative Administration: a Prospective, Observational Study

Spinal surgery is associated with intense pain and associated to a history of preoperative chronic pain. Pregabalin is licensed to treat chronic neuropathic pain, particularly when high dose of opioid are required. Preoperative pain is associated with high postoperative pain scores and opioid requirement promoting persistent hyperalgesic state. The investigators will evaluate the postoperative opioid consumption and pain scores in patients scheduled for lumbar surgery and taking pregabalin since more than 15 days and compare with preoperative pregabalin-free patient that will receive pregabalin only during surgery.

Patients will be prospectively included and compared according their preoperative medication: pregabalin-treated patients (>more than 15 days) for neuropathic pain associated to spinal surgery and pregabalin-free patients for whom pregabalin will be prescribed for 48 hours. Patients will be included without randomization as an observational study. All the patients will receive multimodal analgesia and intraoperative management will be standardized. The main outcome will be the amount of oxycodone during the first 24h after surgery. Other outcomes include pain scores, the quantification of the neuropathic pain diagnostic questionnaire (DN4), nausea and vomiting, length of stay, side-effects of pregabalin and opioid. Patients were also evaluated at three months for pain scores and DN4 score. Postoperative evaluation will be performed in a single-blind manner with investigators not include in the recruitment or the peroperative period.

Inclusion Criteria:

• American Society Anesthesiologist Physical status (ASA) 1-3
• Age ≥18 years old
• Spinal surgery: discectomy, posterior or transforaminal lumbar interbody fusion limited to 2 levels, lumbar disk prosthesis
• Able to participate personality, has given free and inform consent in French
• Affiliated of beneficiary of a system of social security

Exclusion Criteria:

• Age less than 18 years or higher than 85 years old
• Refusal to participate or provide written consent
• Surgery with a combined anterior and posterior approach
• Emergency surgery, reintervention, spine fracture, metastasis
• Tricyclic antidepressant use
• Pregabalin use for other indication: other neuropathy, epilepsy, generalized anxiety disorder
• Pregnancy
• Lack of understanding of NRS and/or DN4 scores
• Hypersensibility or contraindication to levobupivacaine, paracetamol, nefopam, ketoprofen and/or oxycodone
• Participation in another clinical study