The Effect of Perioperative Intravenous Lidocaine Infusion on Opioid Consumption After Lumbar Spine Surgery

The purpose of this study is to determine whether an infusion of lidocaine during surgery can reduce the need for postoperative opioid pain medication use in patients undergoing lumbar spine surgery.

Participants will be recruited by spine surgeons from their pool of patients who are presenting for surgery at University of Vermont Medical Center. If they agree to participate, patients will be assigned at random to receive either an infusion of lidocaine during surgery, or an infusion of saline with 5% dextrose. Subjects will also be asked to complete a 15-item questionnaire that asks about health, quality of life, and level of pain, at three timepoints. Patients will also be asked to rate their level of pain at multiple timepoints after surgery, and we will collect the additionally data from patients' medical records.

Lidocaine has analgesic and anti-inflammatory effects. It has been shown to reduce early postoperative pain and nausea. Additionally, lidocaine has been shown to have positive effects in the recovery of bowel function, with a reduction in time to first flatus, first bowel sounds, first bowel movement, and is associated with a reduction of ileus. Because of these facts, lidocaine infusion has become part of enhanced recovery pathways after bowel surgery at our institution and others.

There are few trials examining the use of lidocaine for orthopedic procedures and many of these studies have contradictory adults. An article by Martin et al. found no benefit in pain or recovery after total hip arthroplasty. By contrast, Farag and colleagues found that lidocaine significantly improves postoperative pain after major spine surgery. Additionally, quality of life scores at one and three months after surgery were significantly higher in the lidocaine group. When our Spine Surgery Analgesic Protocol for major spine surgery at University of Vermont Medical Center was revised in 2015, a lidocaine infusion was added to the protocol.

Studies for lidocaine use in minor lumbar surgery are scant. In one study of 50 patients in Korea, patient pain scores and fentanyl consumption were significantly lower in the lidocaine infusion group (1.5 mg/kg bolus plus 2 mg/kg/hr infusion) at 2, 4, 8, 12 and 24 hours after surgery. Of note, the Cleveland Clinic Outcomes group is currently enrolling 440 patients in a study in which half will receive lidocaine and ketamine infusions.

A reduction in opioid use may lead to the potential reduction of opioid-related side effects, such as nausea, constipation, and hyperalgesia, as well as more serious consequences such as respiratory depression and abuse. There is also the possibility of a length of stay reduction which has potential financial benefits.

This is a randomized, controlled, double-blind study involving patients undergoing one- or two-level posterior lumbar instrumented spinal fusion with or without decompression.

The University of Vermont Medical Center operating rooms will be utilized for this investigation. For the study group, we plan to prospectively recruit 140 patients 18-75 years of age. Recruitment will be done by the participating orthopedists and neurosurgeons, from their own patients. After an informed consent discussion, patients will be randomly assigned to receive 1 mg/kg lidocaine bolus and intraoperative infusion of 2 mg/min (intervention arm) or no lidocaine (control arm). All patients will receive adequate pain control medication according to their needs. Subjects will complete the 15-question Quality of Recovery assessment at baseline and at 36 and 60 hours after surgery. Using the electronic medical system, the following information with extracted: Total morphine equivalent used in house at 36 hours, total morphine equivalents used at 60 hours, visual analog scale pain scores at 4, 8, 12, 24, 36, and 60 hours, length of stay, incidence of nausea requiring medication, time to first flatus, and time to first bowel movement. Subjects will receive a patient-controlled analgesia pump for the first 36 hours after surgery.

Randomization will be performed by the University of Vermont Medical Center Investigational Pharmacy Drug Service (IDS). IDS will generate a table of random numbers and assign those numbers in a 1:1 ratio of active drug to placebo, in blocks of 4. Following informed consent, a member of the study team will notify IDS, which will prepare syringes for the bolus dose and a bag for the infusion, both containing either active drug or placebo. The syringes and bag will be labeled with the subject's name, medical record number, and randomization number.

Eligibility Criteria:
Inclusion Criteria:

* Patient undergoing one- or two-level posterior lumbar fusion with or without decompression at University of Vermont Medical Center
* 18-75 years of age
* Signed consent form

Exclusion Criteria:

* Allergy to lidocaine
* Contraindication to lidocaine, such as substantial hepatic impairment (alanine aminotransferase or aspartate transaminase more than twice normal), renal impairment (serum creatinine \>2 mg/dl)
* Seizures or a history of seizure disorder
* Congestive heart failure
* Arrythmias
* Chronic opioid use \>45 mg morphine equivalent per day
* Trauma patients
* Inter-body fusions
* Severe psychiatric comorbidities
* Planned epidural anesthesia or analgesia