Erector Spinae Block for Spine Surgery

This will be a double blind prospective randomized control trial comparing liposomal bupivacaine with plain bupivacaine in their effectiveness in ESP blocks in lumbar spinal fusion surgery. Patients scheduled for a lumbar spinal fusion procedure will be identified at the time of the scheduled surgery. The endpoints of this study include: The primary objective is to compare the amount of postoperative intravenous opioid consumption among two study groups for the first 72 hours: Patients undergoing posterior lumbar spinal fusion surgery (1-2 levels) under general anesthesia and ESP block with liposomal bupivacaine + 0.25% bupivacaine and patients undergoing posterior lumbar spinal fusion surgery (1-2 levels) under general anesthesia and ESP block with 0.25% bupivacaine The secondary objectives include: Compare the severity of pain at rest at specific timepoints postoperatively. Compare general quality of recovery via QoR-15 at 48 hours, 72 hours and then at routine follow up visits occurring 2 weeks, 6 weeks, and 12 weeks postoperatively. Measure rate of postoperative nausea/vomiting in PACU. Measure time to ambulation. Compare analgesia satisfaction score at time of discharge. Measure hospital length of stay.