Effect of Opioid-Free Versus Opioid-Based Anesthesia in Discectomy Surgery

Study Design and Methodology:This is a single‐center, prospective, randomized, double‐blind, parallel‐group,active‐controlled clinical trial. A total of 46 adult patients scheduled for electivelumbar discectomy surgery under general anesthesia at Zagazig University Hospitals willbe enrolled. Participants will be randomly assigned in a 1:1 ratio to one of twotreatment arms using computer‐generated randomization. The study will employdouble‐blinding where both participants and outcome assessors will be unaware of groupassignments.Intervention Protocols:Opioid‐free Anesthesia (OFA) Group: Patients will receive a multimodal non‐opioid regimenconsisting of: dexmedetomidine loading dose 1 µg/kg intravenous (IV) over 10 minutesbefore induction, followed by continuous infusion at 0.2‐0.7 µg/kg/hr; ketamine 0.25‐0.5mg/kg IV at induction, followed by infusion at 0.1‐0.3 mg/kg/hr; and propofol infusion(4‐12 mg/kg/hr) for anesthesia maintenance.Opioid‐based Anesthesia (OBA) Group (Active Comparator): Patients will receive fentanyl 2µg/kg IV at induction, followed by continuous infusion of 1 µg/kg/hr, along with propofolinfusion (4‐12 mg/kg/hr) for maintenance.Both groups will receive standardized premedication (pantoprazole 40 mg, ondansetron 4mg), antibiotic prophylaxis, neuromuscular blockade with atracurium, and reversal withneostigmine and atropine. Intraoperative ventilation parameters will be adjusted tomaintain EtCO₂ between 35‐40 mmHg.Postoperative Management:All patients will receive scheduled postoperative analgesia with paracetamol 1 g every 6hours and intramuscular diclofenac 75 mg (maximum 150 mg/day). Rescue analgesia with IVnalbuphine (0.1‐0.2 mg/kg, maximum 160 mg/day) will be administered for Visual AnalogScale (VAS) scores >3. Pain assessment will occur at baseline (immediate postoperative),2, 6, 12, and 24 hours postoperatively.Data Collection and Assessment:Data will be collected preoperatively (demographics, medical history), intraoperatively(hemodynamic parameters, drug consumption), and postoperatively (pain scores, sedationlevels, analgesic requirements, adverse events). Sedation will be assessed using theModified Ramsay Sedation Score at 2‐hour intervals for the first 12 hours, then every 4hours for the next 12 hours. Hemodynamic stability will be monitored by recording bloodpressure, mean arterial pressure, heart rate, and respiratory rate at predefinedintervals.Statistical Considerations:Sample size calculation was based on detecting a difference in VAS scores between groups,with 80% power and 95% confidence level, yielding 42 patients plus 4 additional (10%dropout compensation), totaling 46 participants (23 per group). Data analysis will beperformed using SPSS version 20.0, with appropriate statistical tests (t‐tests, ANOVA,chi‐square) and correction for multiple comparisons using Benjamini‐Hochberg FalseDiscovery Rate.Ethical and Regulatory Aspects:The study protocol has been submitted for approval to the Zagazig UniversityInstitutional Review Board (IRB). Written informed consent will be obtained from allparticipants. Patients retain the right to withdraw from the study at any time withoutaffecting their medical care. The study will comply with Good Clinical Practiceguidelines and the Declaration of Helsinki.Study Duration and Timeline:The total study duration is anticipated to be 6 months, including patient recruitment,intervention, follow‐up, and data analysis. Results will be disseminated through academicpublication and presentation.