Liposomal Bupivacaine in One-level Instrumented Posterior Spinal Fusion

Inclusion Criteria:

• Has a primary diagnosis of single-level lumbar stenosis, disc herniation, and/orspondylolisthesis excluding degenerative disc disease

• Receives open, one-level posterior spinal fusion

Exclusion Criteria:

• Is opioid-tolerant. Opioid tolerant patients are receiving, for one week or longer,at least 60 mg oral morphine/day, 25 mcg transdermal fentanyl/hour, 30 mg oraloxycodone/day, 8 mg oral hydromorphone/day, 25 mg oral oxymorphone/day, or anequianalgesic dose of another opioid.

• Experienced intraoperative complications (i.e., a dural tear or durotomy). Intra-and post-operative data will be excluded from the analysis for these patients.

• Has severe liver disease. Bupivacaine is primarily metabolized in the liver viaconjugation with glucuronic acid. Patients with liver disease, especially severedisease may be more susceptible to toxicity.

• Has severe renal disease. Bupivacaine and the metabolite are primarily excreted bythe kidneys. Excretion can be significantly changed by urinary perfusion, thepresence of renal disease, factors affecting urinary pH, and renal blood flow

• Is less than 18 years old.

• Is pregnant.

• Cannot read and speak English.