Evaluation of Abdominal Wall Block With Liposomal Bupivacaine for Post-Operative Analgesia in Donor Nephrectomy

This is a blinded (patients are blinded and all the staff and the nurses who collect data are also blinded) randomized controlled trial in living kidney donors who have been approved by a multidisciplinary (nephrology, urology, psychiatry, and social work) team to proceed with donor nephrectomy. Patients will be approached to participate in the study only after they have agreed to kidney donation and have been informed of all of the associated risks. Participants are informed that they can withdraw from kidney donation at any time until they are in the operating room.

Patients meeting these criteria, who also consent to participate in the study, will be randomized (standard of care pain medication vs TQL block). The ratio of male to female patients in each arm will be equal because of the known increased risks for post-operative nausea/vomiting (PONV) in females. The study group will receive a liposomal bupivacaine TQL block after the induction of general anesthesia and liposomal bupivacaine transverse abdominis plane (TAP) block after closure of the midline fascia. All patients including the control group will have infiltration of the skin edges with bupivacaine. Control patients will have a TAP block with 5 cc of bupivacaine on both sides. A placebo 22g needle will be placed at the same site as the TQL block without injection. Intra-operative narcotics will be administered by the anesthesia team based on standard criteria. All participants will receive intravenous ketorolac and acetaminophen at the end of the procedure. Intravenous ketorolac will be continued for 24 hours while hospitalized. Post-operative pain management with intermittent parenteral and enteral narcotics as needed will be the same in both groups.

Liposomal bupivacaine block administration:

After induction of general anesthesia, surgical team will turn the patient to the lateral position (final position for surgery). After prep with and drape, investigators will place ultrasound probe in mid- posterior axillary line, just above iliac crest. The investigators will identify abdominal wall muscles including external oblique, internal oblique, transverse abdominis, and quadratus lumborum as well as thoracolumbar fascia with the help of ultrasound. Then, investigators will insert a 22g nerve block needle and advanced it under direct guidance of ultrasound until it is below the fascial covering of the quadratus lumborum muscle layer or its fascia which forms a continuous fascia compartment with thoracolumbar fascia. After aspiration to rule out intravascular location of the needle, investigators will be inject 20 mL of liposomal bupivacaine mixed with 10ml of normal saline under ultrasound guidance, to monitor spread of the injected fluid . The investigators will aspirate repeatedly every 5cc of local anesthetic. The investigators will remove the needle upon completion of the injection.

The following study variables will be collected postoperatively following arrival in the post-anesthesia care unit. Current and maximum intensity pain scores will be documented by nurses in EHR. Total opiate dose consumed every 24 hours will be collected from the EHR and pain diary after discharge. Patient satisfaction will be evaluated using the Revised American Pain Society Patient Outcome Questionnaire (APS-POQ-R) 24 hours' post-procedure. Incidence of nausea will be extracted from nursing notes

Complications will be documented by anesthesia pain service that will follow these patients while admitted.

Outpatient use of narcotics, pain assessment, bowel function, sexual function complications from the block or the donor surgery, and attitudes toward kidney donation will be evaluated with validated survey instruments. Please see the timeline for the collection of the data prior to and after kidney donation. The survey data will be collected using secure links to a REDCap server 3, 5, 10, 30, and 90 days after surgery.