TAP Block With Plain Bupivacaine Versus Wound Infiltration With Exparel for Postoperative Pain Management

Transversus Abdominis Plane (TAP) Block With Bupivacaine Versus Wound Infiltration With Liposomal Bupivacaine (Exparel) for Postoperative Pain Management After Open Total Abdominal Hysterectomy: a Prospective Randomized Controlled Trial

In this randomized, controlled, observer-blinded study we plan to evaluate pain relief after ultrasound-guided transversus abdominis plane (TAP) block using bupivacaine and wound infiltration using liposomal bupivacaine in patients undergoing abdominal hysterectomy.

Patients undergoing open total abdominal hysterectomy at Parkland Hospital (n=60) will be randomized into one of two groups to receive either ultrasound-guided bilateral TAP block with bupivacaine (Group 1) or infiltration of the surgical wound with liposomal bupivacaine (Group 2) for postoperative pain management. The remaining aspect of perioperative care, including the general anesthetic technique, postoperative care will be standardized and will be similar for all patients. The duration of the involvement in the study will be until 48 hours postoperatively. The pre-anesthesia care unit personnel will identify patients during their preoperative clinic visit.

Patients in Group 1 will receive ultrasound-guided bilateral TAP block at the end of the surgery. Patients in Group 2 will receive Exparel prior to closing the incision which will be injected subfascially and subcutaneously. In the first 24-h postoperative period, patients in both Groups will receive acetaminophen 1000 mg every 6 h orally, ketorolac 30 mg, IV every 6 h, orally and morphine via an intravenous patient controlled analgesia (IV-PCA) system to maintain adequate pain control. In the 24-48 h study period, all patients will receive oral ibuprofen 800 mg and acetaminophen 1000 mg three times a day and a combination of hydrocodone/acetaminophen 5mg/ 325 mg 1-2 tablets, as needed.

The postoperative analgesia will be documented using the visual analog score (0=no pain, 10=worst pain). In addition, total opioid dose over the 48-h study period will be documented. Postoperative nausea will be measured using a categorical scoring system (none=0, mild=1, moderate=2, severe=3) and episodes of vomiting will be documented. Rescue antiemetics will be given to any patient who complains of nausea and/or vomiting.

All variables will be assessed at 2, 6, 12, 24, and 48 hours, postoperatively by an investigator blinded to group allocation.

Inclusion Criteria:

• Female
• ASA physical status 1-3
• Scheduled for open abdominal hysterectomy
• Age 18-80 years old
• Able to participate personally or by legal representative in informed consent in English or Spanish

Exclusion Criteria:

• History of relevant drug allergy
• Age less than 18 or greater than 80 years
• Chronic opioid use or drug abuse
• Significant psychiatric disturbance
• Inability to understand the study protocol
• Refusal to provide written consent