Comparing TAP Blocks Bupivacaine, and Placebo for Plane

The study will prospectively compare the analgesic efficacy of TAP blocks with liposomal bupivacaine, plain bupivacaine, and placebo in patients who are scheduled for major abdominal surgery. The primary aim is to assess the duration of the local analgesia (determined by pinprick and cold) in all four quadrants. Comparing opioid consumption and pain scores is a secondary aim. All aims will be assessed over 72 hours or the duration of hospitalization if shorter.