Transversus abdominis plane block with liposomal bupivacaine and its effect on opiate use after weight loss surgery: a randomized controlled trial.

BACKGROUND: Liposomal bupivacaine (LB), as an extended-release local anesthetic, may provide lasting pain control and therefore decrease the need for narcotics in the immediate postoperative period. OBJECTIVES: The aim of this study was to evaluate whether transversus abdominis plane (TAP) block with LB decreased the use of postoperative narcotics compared with regular bupivacaine (RB) and no TAP block in patients undergoing weight loss procedures. SETTING: A large, metropolitan, university-affiliated, tertiary hospital. METHODS: Patients undergoing laparoscopic Roux-en-Y gastric bypass, sleeve gastrectomy, or sleeve-to-bypass conversion over 1 year were randomized to receive TAP block using LB, TAP block with RB, or no block in a double-blind, randomized controlled trial. The outcomes measured were postoperative use of opiates, pain score, length of stay, time to ambulation, and nausea. Data were analyzed using χ2 test and analysis of variance F test. RESULTS: Two hundred nineteen patients were included in the study. Fentanyl patient-controlled analgesia usage was not significantly different between the groups (LB 351.4 versus RB 360.7 versus no TAP block 353.9, P = .97) at 48 hours post operation. The pain scores (scale 1-10) were similar among the groups with the mean for the LB group at 4.3, and RB and no TAP block groups both at 4.7 (P = .35). The type of block or lack of block did not significantly impact the length of stay, time to ambulation, or presence of nausea. CONCLUSION: The LB TAP block did not significantly reduce the total opiate pain medication consumption nor did it reduce pain scores among bariatric surgery patients.