Comparing Liposomal Bupivacaine Versus Standard Bupivacaine in Colorectal Surgery

The purpose of this study is to compare the difference between two different pain control methods in patients who will be having a colorectal surgery

Quadratus lumborum (QL) blocks will be done intraoperatively after induction. All procedures will be placed under the supervision of the attending anesthesiologist on the acute pain service. All patients will receive 1 gm acetaminophen and 600 mg gabapentin preoperatively. Patients above 70yo will receive 300mg gabapentin. Patient will be randomized to one of the two arms. For the QL block, Shamrock sign consistent of the quadratus lumborum muscle, psoas major muscle, erector spinae muscles and the L4 transverse process will be identified. Under ultrasound guidance with an in-plane technique, the needle will be advanced into the fascial plane between the quadratus lumborum and psoas major muscles. For the liposomal bupivacaine (LB) group, 0.125% bupivacaine 20ml plus Exparel®10ml will then be injected into the fascial plane on each side. For the standard bupivacaine (SB) group. 30ml 0.25% bupivacaine will be injected on each side. Saline will be used for hydro-dissection until the QL block target is confirmed on ultrasound. As part of the enhanced recovery after surgery (ERAS) protocol, all patients will receive ketamine and lidocaine drip during surgery, which is the investigator's current standard of practice. All patients will be scheduled on PO acetaminophen and PO gabapentin daily postoperatively per ERAS protocol. PO oxycodone as needed (PRN) will be started once patients tolerate diet. PRN IV dilaudid may be given for severe breakthrough pain. Opioid usage at 1, 24, 48 and 72 hours after the block will be recorded by a member of the research team. Pain scores at rest and on movement (knee flexion) will be measured by the investigator using Visual Analog Scale (VAS). Nausea will be measured using a categorical scoring system (none=0; mild=1; moderate=2; severe=3). Sedation scores will also be assessed by a member of the study team using a sedation scale (awake and alert=0; quietly awake=1; asleep but easily roused=2; deep sleep=3). All these parameters will be measured at 1, 24, 48 and 72 hours after the QL block and patients will be encouraged to ambulate on postoperative day 1 under supervision. Their ambulation activity will be recorded.