Background: The authors tested the primary hypothesis that perioperative IV lidocaine administration during spine surgery (and in the postanesthesia care unit for no more than 8 h) decreases pain and/or opioid requirements in the initial 48 postoperative hours. Secondary outcomes included major complications, postoperative nausea and vomiting, duration of hospitalization, and quality of life.
Methods: One hundred sixteen adults having complex spine surgery were randomly assigned to perioperative IV lidocaine (2 mg·kg·h) or placebo during surgery and in the postanesthesia care unit. Pain was evaluated with a verbal response scale. Quality of life at 1 and 3 months was assessed using the Acute Short-form (SF) 12 health survey. The authors initially evaluated multivariable bidirectional noninferiority on both outcomes; superiority on either outcome was then evaluated only if noninferiority was established.
Results: Lidocaine was significantly superior to placebo on mean verbal response scale pain scores (P < 0.001; adjusted mean [95% CI] of 4.4 [4.2-4.7] and 5.3 [5.0-5.5] points, respectively) and significantly noninferior on mean morphine equivalent dosage (P = 0.011; 55 [36-84] and 74 [49-111] mg, respectively). Postoperative nausea and vomiting and the duration of hospitalization did not differ significantly. Patients given lidocaine had slightly fewer 30-day complications than patients given placebo (odds ratio [95% CI] of 0.91 [0.84-1.00]; P = 0.049). Patients given lidocaine had significantly greater SF-12 physical composite scores than placebo at 1 (38 [31-47] vs. 33 [27-42]; P = 0.002) and 3 (39 [31-49] vs. 34 [28-44]; P = 0.04) months, postoperatively.
Conclusion: IV lidocaine significantly improves postoperative pain after complex spine surgery.