Intravenous Lidocaine Infusion with Single Low-Dose Ketamine as an Adjuvant to General Anesthesia in Posterior Spine Fusion

Background: Posterior spinal fusion (PSF) is a common surgical operation used to correct degeneration of the lumbar spine with considerable postoperative pain. The primary objective of this study is to compare the total intraoperative and postoperative opioid consumption and numeric pain scale during the first 24 hours after surgery between the lidocaine/ketamine group and the narcotic-only group. Materials and Methods: Sixty adult patients (age 18–65 years) scheduled for elective PSF were included. Patients were divided randomly into either the lidocaine/ketamine group (LK group), who received lidocaine and ketamine injection in addition to usual perioperative narcotic analgesia, and the narcotic-only group (N group) who depended on narcotics only. The primary outcome measures were total intraoperative and postoperative opioid consumption and pain scores during the first 24 hours postoperatively. The secondary outcome measures were sedation score, intravenous rescue analgesia, postoperative nausea and vomiting, and pruritis during the first 24 hours postoperatively. Results: Patients in the LK group had lower intraoperative fentanyl consumption (216.3 ± 28.8 μg) than those in the N group (363 ± 35 μg). The LK group consumed less morphine during the first 24 hours after surgery (49.5 ± 6.0 mg) than the N group did (57.8 ± 8.6 mg). The LK group had lower pain scores at all-time intervals during the first 24 hours (2, 6, 12, and 24 hours) than the N group did. Conclusions: Intraoperative lidocaine infusion with low-dose ketamine reduced opioid consumption and pain scores in patients undergoing PSF