Comparison of Exparel to Bupivacaine With Dexamethasone in TAP Block

The purpose of this study is to compare the efficacy and duration of bupivacaine extended-release liposome injection (Exparel) versus bupivacaine with dexamethasone in transversus abdominis plane (TAP) blocks for patients undergoing abdominal surgery at Emory University Hospital and Emory University Hospital Midtown.

The investigators hypothesize that Exparel will provide greater postoperative pain relief than bupivacaine with dexamethasone. The investigators plan to enroll up to 50 male and female subjects meeting inclusion and exclusion criteria who will be randomized to receive either Exparel (Group 1) or bupivacaine with epinephrine and dexamethasone (Group 2) in the TAP block to achieve at least 22 subjects in each group

Group 1 will be administered 266 mg of Exparel, diluted to 30 mL. Group 2 will be given 28 mL of 0.375% bupivacaine and 8mg/2 mL dexamethasone.Before injection of the study medication, 2mL of normal saline with be injected under ultrasound visualization to ensure needle tip is in the transversus abdominis plane.Randomization will occur following the written informed consent and prior to the start of the surgical procedure. Postoperatively, study patients will receive intravenous acetaminophen 1000mg every 8 hours for 3 doses, then oral acetaminophen 650mg every 6 hours. Subjects will also have patient-controlled analgesia (PCA) with morphine or hydromorphone. The research staff recording data will be blinded to the treatment group. Demographic data will be recorded, including age, date of birth, height and weight to ensure similarity between the two groups. A medical history will be obtained as well as surgical and anesthesia details. Study patients will be followed for 72 hours postoperatively to record the amount of opioid consumption, as well as other pain score data using the Visual Analogue Scale (VAS).The subject's participation will end 72 hours after surgery. A telephone interview will occur with the subject if hospital discharge occurs prior to 72 hours.

Eligibility Criteria:
Inclusion Criteria:

* Male and female patients undergoing scheduled abdominal surgery at Emory University Hospital or Emory University Hospital Midtown
* Patients willing and able to provide written informed consent

Exclusion Criteria:

* Patients less than 18 years of age, since Exparel has not been studied in this age group
* Patients who are pregnant or lactating, since Exparel has not been shown to be safe in this population, and because of potential drug transfer to child
* Patients with uncontrolled diabetes since dexamethasone may cause hyperglycemia
* Patients with liver dysfunction, since bupivacaine is hepatically metabolized
* Patients with renal failure, since bupivacaine is renally excreted, defined as requiring hemodialysis or renal replacement therapy
* Patients with allergy to one of the study drugs
* Patients with local infection, which may be exacerbated by dexamethasone
* Patients with significant opioid tolerance, defined as taking at least 60 mg oral morphine per day, 3 mg oral oxycodone per day, 25 mcg/hr fentanyl patch, 25 mg oral oxymorphone per day, 8 mg of oral hydromorphone per day or an equianalgesic dose of another opioid for one week or longer
* Patients with known coagulopathy, since bleeding risk is higher Patients who are getting neuraxial anesthesia for surgery