Perioperative intravenous lidocaine as an analgesic adjunct in adolescent idiopathic scoliosis surgery

Opioids are the mainstay of pain management in scoliosis surgery. We hypothesized that in adolescent idiopathic scoliosis (AIS) patients undergoing posterior spinal fusion (PSF) surgery, perioperative intravenous (IV) lidocaine would reduce postoperative opioid requirement and pain scores. In this retrospective observational before-and-after study, we identified AIS patients who underwent single-stage PSF at a tertiary university hospital from 2020 to 2022. All patients received total intravenous anesthesia. The Lidocaine group received a bolus of 1.5 mg/kg IV lidocaine prior to induction, followed by infusion at 2 mg/kg/h. At wound closure, the rate was reduced to 1 mg/kg/h and continued for 30 min in recovery. All patients received patient-controlled analgesia (PCA) morphine postoperatively. The primary outcome was total morphine consumption in the first 24 h. The secondary outcome was mean pain scores over 48 h using a numerical rating scale. We included 115 patients: 59 in the Usual Care group and 56 in the Lidocaine group. Postoperative morphine use in the first 24 h showed no significant difference (Lidocaine: 13.5 ± 8.9 mg vs Usual Care: 13.9 ± 10.6 mg; P = 0.821). The cumulative morphine milligram equivalents per kilogram bodyweight at 48 h was 0.43 mg/kg. Mean pain scores were higher in the Lidocaine group in the first 48 h (4.25 ± 0.37 vs 3.67 ± 1.46; P = 0.03). Perioperative IV lidocaine administered as an analgesic adjunct for AIS surgery did not reduce postoperative morphine requirement. Although pain scores were statistically higher in patients receiving intravenous lidocaine, the difference was minimal and lacked clinical significance.