Exparel Use in Bilateral TAP Blocks for Postoperative Pain Control

Exparel is liposomal form of bupivacaine, a local anesthetic. Secondary to its liposomal nature, Exparel slowly releases bupivacaine into the area injected (ultrasound guided field block) so that it may provide relief from pain for up to 48-72 hours time.

Exparel in TAP blocks may be performed on patients undergoing open or laparoscopic hand assisted abdomen/pelvic procedures, who are NOT candidates for an epidural (anticoagulation medication use, history of spine surgery with metal hardware of the mid-lower back) or as a rescue block for patients who undergo laparoscopic surgery but converted to open abdominal surgery in the operating room.

This block is usually performed intraoperatively (before patient wakes up from anesthesia) or in the immediate postop recovery unit (PACU) area.

Anesthesia personnel who have been well trained to perform ultrasound guided bilateral TAP blocks will combine Exparel 20 cc's with 0.25% Bupivicaine 20 ccs and 20 ccs of normal saline into a 60 cc syringe. With ultrasound machine, they will locate the TAP block on each side of abdomen with a Stimuplex needle. Once the TAP area is found, hydrodissection with normal saline is used to confirm TAP area, and then 30 ccs of the Exparel/0.25% Bupivacaine/normal saline solution administered to each side.

Patients are seen in the PACU area, where pain scores and oral morphine equivalents (OME) are calculated. Patient seen in postoperative day (POD) 1 to discuss expectations of pain control and goals for pain management (i.e. use of multimodal pain regimen and goals to decrease opioid use). A flyer (approved by the Patient Education Committee) is provided to patient on POD 1 for further patient education. Pain scores and OMEs calculated for POD 0-5. Progress notes in patient's chart and patient interview also discloses if patient had episodes of N/V, another data point we will collect. We will finally review patient charts for length of admission (date of admission to date of discharge) Our control group: patients that had open abdominal or hand assisted laparoscopic surgery and who did not receive a TAP block, and received mainly opioids for postop pain control. For the comparison (control) group, we will calculate OME requirements while in PACU, and from POD 1-POD 5. We will see patients during POD 1 to discuss expectations of pain control and goals for pain management. Progress notes in patient's chart and patient interview also discloses if patient had episodes of N/V, another data point we will collect. We will finally review patient's chart for length of admission (date of admission to date of discharge) We are looking for an N=20 for the Exparel TAP block (experimental) group and N=20 for no TAP block (control) group

Inclusion criteria

• Women of Reproductive Potential
• Men of Reproductive Potential
• Minorities
• Healthy Controls/Volunteers
• Employees/Students
• Vulnerable populations (trauma victims, students > 18 yrs age, aged infirm, substance abusers, impoverished, terminally ill,)

patients of above inclusion criteria who 1) are not candidates of an neuraxial blockade (i.e. epidural) for postoperative pain control 2) who underwent a laparoscopic to open procedure intraoperatively

Exclusion criteria

• advanced dementia, not oriented to time or place
• advanced liver disease
• pregnant patients
• allergy to amide local anesthesia
• allergy to methemoglobinemia