A Prospective Randomized Trial of Transversus Abdominis Plane (TAP) INtraoperative Block With Bupivacaine/Dexamethasone aGainst Liposomal Bupivacaine (Exparel®): the TINGLE Trial

Postoperative pain can pose significant challenges in the postoperative recovery of patients undergoing major colorectal surgery. Traditionally, opioids have played an important role in treating postoperative pain. It is well established that opioids are highly effective in relieving pain; however, opioids are associated with numerous side effects that include nausea, vomiting, constipation, ileus, bladder dysfunction, respiratory depression, pruritus, drowsiness, sedation, and allergic reaction. These opioid side effects, which range in severity, can significantly interfere with discharge home, particularly following colorectal surgery. Significant interest has grown for the use of guided regional anesthesia, specifically the use of the transversus abdominis plane (TAP) block to extend the post-operative analgesic window and ultimately limit opioid use. While bupivacaine formulations including a steroid has been shown to prolong the anesthetic effects of the regional field block, a new liposomal-depo formulation of bupivacaine (Exparel) has gained popularity and has additionally been shown to provide extended analgesia. Although promising data exists surrounding each modality, liposomal bupivacaine has not been studied in a well-powered clinical trial specifically in colorectal patients nor compared to a bupivacaine/steroid mixture.

We are proposing a prospective randomized study of patients undergoing major laparoscopic colorectal surgery to compare the analgesic effects of a bupivacaine/steroid mixture versus liposomal bupivacaine (Exparel). We hypothesize that the liposomal formulation of bupivacaine will provide superior perioperative pain control at 48 hours post-operation measured by total consumed oral morphine equivalents. In addition, we will measure postoperative pain scores, time until ambulation, antiemetic use, length of postoperative hospital stay, postoperative ileus, and adverse events directly related or unrelated to TAP block in the 30-day postoperative period between the three groups.