Analgesic Efficacy of Intravenous Lidocaine for Postoperative Pain Following Adult Spine Surgery

Inadequate pain control after spine surgery in adults can result in increased patient
morbidity and length of hospital stay, whereas improved postoperative pain control has been
demonstrated to have numerous physiologic benefits and to reduce postoperative
complications. When administered systemically, the amide local anesthetic lidocaine has
potent anti-inflammatory properties, including inhibition of the arachidonic acid cascade
and production of eicosanoids and prostaglandins. Previous studies have confirmed that the
continuous intravenous administration of lidocaine during and after abdominal surgery in
adults improves patient rehabilitation (specifically, pain intensity, duration of ileus,
incidence of nausea and vomiting), and shortens hospital stay. The beneficial
anti-inflammatory properties versus untoward side effects of the local anesthetics appear
superior to steroids and the non-steroidal anti-inflammatory drugs (NSAIDs). Moreover,
concern and controversy exists regarding the adverse effects of NSAIDs on bone healing,
particularly in adults undergoing spine surgery.

No study to date has investigated the efficacy of a continuous perioperative lidocaine
infusion in the adult spine surgery population. Therefore, in this prospective, randomized,
controlled trial, we will evaluate the analgesic efficacy, anti-inflammatory properties, and
rehabilitation pattern with a continuous, perioperative intravenous infusion of lidocaine
versus a normal saline placebo in adult patients undergoing a decompressive lumbar
laminectomy for spinal canal stenosis. Subjects enrolled in this study will receive a
standardized general anesthetic that is consistent with our present clinical practice. The
study participants will be randomized to receive both a perioperative bolus (2 mg/kg) and
subsequent intravenous infusion (3 mg/kg/hr) of the amide local anesthetic lidocaine or a
normal saline placebo at an equal volume per hour. The study infusion will be continued for
90 minutes after surgery. All patients will receive ample and adequate intravenous doses of
an opioid (morphine sulfate) to reduce their pain intensity to acceptable levels. Pain
intensity, opioid requirements, opioid-related side effects, and both the immediate and
sustained rehabilitation pattern will be assessed. In addition to plasma lidocaine levels in
the active drug group, plasma C-reactive protein, cortisol, and cytokine levels (e.g., IL-6,
IL-10 and TNF-α) will be obtained at a series of perioperative time points in all study
patients. Postoperative cytokine levels will also be measured in the surgical drainage
fluid.