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

• Postanesthesia care unit(PACU)admission duration (in minutes) [ Time Frame: Assessed after discharge from PACU ] [ Designated as safety issue: No ]
  
• Post extubation requirement for intravenous fentanyl in operating room (Y/N and mcg/kg) [ Time Frame: Post extubation ] [ Designated as safety issue: No ]
  
• Time to first nurse administered morphine dose after PACU admission (in minutes) [ Time Frame: Assessed after PACU admission ] [ Designated as safety issue: No ]
  
• Total dose of fentanyl administered intraoperatively (mcg/kg) and in the PACU (mcg/kg) [ Time Frame: Measured post op ] [ Designated as safety issue: No ]
  
• Total amount of mophine administered/PCA pump demands and doses and ratio of PCA demands/doses [ Time Frame: 48-72 hours postoperative period ] [ Designated as safety issue: No ]
  
• Self reported VAS pain scores (on a 0-100 scale) [ Time Frame: Obtained on admissions to and upon discharge from PCAU, every 4 hours thereafter for the first 48 to 72 hours postoperatively, and at time of initial postoperative mobilization ] [ Designated as safety issue: No ]
  

• Side effect analysis [ Time Frame: Measurements of side effect analysis will be done postoperatively ] [ Designated as safety issue: No ]
  
• Pain Intensity Questionnaires [ Time Frame: BPI-SF completed at time of initial and subsequent postop visits, Roland Morris Back Pain Questionnaire completed postop and 12-14 days, 3 mos, 6 mos, 12 mos, and 24 mos postop as compared to baseline value ] [ Designated as safety issue: No ]
  
• Length of hospital stay [ Time Frame: From admission to discharge ] [ Designated as safety issue: No ]
  
• Post rehab analysis [ Time Frame: Time to first liquid oral intake, time to initial mobilization, time to discontinuation of study solution infusion, time to discharge order, and to time to actual discharge home ] [ Designated as safety issue: No ]
  

Drug: Lidocaine Hydrochoride Injection, without epinephrine
A standardized 0.2 ml/kg (2 mg/kg) intravenous bolus dose of lidocaine (1%, 10 mg/ml) is given after anesthetic induction but prior to skin incision. Immediately thereafter, lidocaine (1%, 10 mg/ml) will be administered on a standardized 0.3 ml/hr/kg (3 mg/kg/hr, maximum 200 mg/hr = 20 ml/hr) basis using a continuous infusion pump during the surgical procedure. Immediately after skin closure, the lidocaine infusion will be decreased by 50% to 0.15 ml/hr/kg (1.5 mg/kg/hr, maximum 100 mg/hr = 10 ml/hr) and continued for 90 minutes postoperatively. The infusion will be stopped before the patient is discharged from the post-anesthesia care unit (PACU).
Other Name: Xylocaine
Drug: Normal Saline
A standardized 0.2 ml/kg intravenous bolus dose of preservative-free normal saline will be given after anesthetic induction but prior to skin incision. Immediately thereafter, normal saline will be administered on an equal 0.3 ml/hr/kg (maximum 20 ml/hr) basis using a continuous infusion pump during the surgical procedure. Immediately after skin closure, the normal saline infusion will be decreased by 50% to 0.15 ml/hr/kg (maximum 10 ml/hr) and continued for 90 minutes postoperatively. The infusion will be stopped before the patient is discharged from the post-anesthesia care unit (PACU).
Drug: Normal Saline
A standardized 0.2 ml/kg (2 mg/kg) intravenous bolus dose of lidocaine (1%, 10 mg/ml) is given after anesthetic induction but prior to skin incision.

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.