Overview

This randomized, blinded, controlled clinical trial aims to evaluate the effectiveness of ultrasound-guided retrolaminar block in reducing postoperative opioid consumption in patients undergoing lumbar spine fusion surgery under multimodal analgesia.

The participants will:

• Be randomly assigned in a 1:1 ratio to receive either a retrolaminar block with 0.25% bupivacaine plus epinephrine or a sham block (normal saline) prior to surgical incision.
• Receive standardized multimodal analgesia.
• Have follow-up by the Acute Pain Unit during the first 3 days, to assess opioid consumption (morphine) in 24 hours, pain intensity measured by Numeric Rating Scale, quality of recovery assessed by the QoR-15 questionnaire, intraoperative blood loss, and postoperative complications.

Eligibility

Inclusion Criteria:

• Adults aged 18-75 years, scheduled for lumbar spine fusion surgery by a trauma team
• American Society of Anesthesiologists (ASA) Classification I-III
• Willing and able to provide written informed consent to participate in the study.

Exclusion Criteria:

• History of chronic use of strong or weak opioids for more than 3 months.
• Diagnosis of chronic pain and treatment by a pain management team.
• ASA score greater than or equal to 4.
• Patients with prior lumbar spine surgery. Spinal instrumentation at the surgical site.
• Estimated creatinine clearance less than 60 ml/min.
• Coagulation disorder or abnormal coagulation tests.
• Infection at the surgical site.
• Weight less than 50 kg.
• Altered mental status that prevents reliable evaluation.
• Allergy to local anesthetics or analgesic drugs used in the study.
• Patients with contraindications to peripheral nerve blocks.
• Lumbar spine fixation due to oncologic disease or acute trauma.
• Use of intraoperative neuromonitoring and TIVA.