Comparison of Erector Spinae Plane Block and Intravenous Lidocaine in Opioid-Free Anesthesia for Laparoscopic Sleeve Gastrectomy: A Randomized Controlled Trial

Opioid-free anesthesia (OFA) protocols are increasingly adopted in metabolic and bariatric surgery to minimize opioid-related complications. Both erector spinae plane block (ESPB) and intravenous (IV) lidocaine have demonstrated analgesic efficacy in various surgical settings, but direct comparisons in an OFA framework for metabolic and bariatric procedures remain limited. We conducted a prospective, randomized controlled trial comparing ESPB with IV lidocaine in adults with obesity (BMI ≥ 35 kg/m²) undergoing laparoscopic sleeve gastrectomy under OFA. Patients were randomized 1:1 to receive either bilateral ultrasound-guided ESPB before induction or an intraoperative lidocaine infusion. All patients received standardized multimodal analgesia. The primary outcome was total opioid consumption during the first 24 h postoperatively, expressed in IV oxycodone equivalents. Secondary outcomes included pain scores (NRS), intraoperative rescue medication, postoperative nausea and vomiting (PONV), and recovery parameters. Analyses were conducted on a modified intention-to-treat basis. A total of 277 patients were included in the analysis (136 in the ESPB group and 141 in the lidocaine group). The ESPB group demonstrated significantly lower median opioid consumption within the first 24 h postoperatively (2.0 mg vs. 2.5 mg; p = 0.048). Opioid-free recovery (0 mg IV oxycodone equivalents within 24 h) occurred in 47.1% of patients in the ESPB group and 39.0% in the lidocaine group (p = 0.176). NRS scores did not differ significantly between the groups at any assessed time point. Incidences of intraoperative hemodynamic instability, rescue medication use, delayed emergence, and PONV were similar. No serious adverse events or complications related to the block were reported. In the context of OFA for laparoscopic sleeve gastrectomy, both ESPB and intravenous lidocaine were safe and effective analgesic options. ESPB was associated with a statistically significant but clinically modest reduction in 24-hour opioid consumption, while pain scores and recovery outcomes were comparable. Both techniques can therefore be considered appropriate components of OFA, and the choice may depend on patient characteristics, institutional logistics, and anesthesiologist expertise.