Traditionally, opioids are heavily utilized in treating postoperative pain but they are associated with numerous side effects. The use of the transversus abdominis plane (TAP) blocks have become standard practice to extend the post-operative analgesic window and limit opioid use. A new liposomal-depo formulation of bupivacaine (Exparel) has gained popularity as a long-lasting TAP block medication, but has not been studied in a well-powered clinical trial specifically in colorectal patients nor compared to a bupivacaine/steroid mixture which may offer similar effects. We conduct a prospective randomized prospective randomized study of patients undergoing major laparoscopic colorectal surgery to compare the analgesic effects of a bupivacaine/steroid mixture versus liposomal bupivacaine.

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.

Inclusion Criteria:

1. Male or Female
2. Undergoing major laparoscopic colorectal procedure
3. Willingness and ability to sign an informed consent document
4. No allergies to anesthetic or analgesic medications
5. ASA physical status Class I - III
6. Aged 18-90 years

Exclusion Criteria:

1. Refusal to participate in the study

2. Age <18 or > 90 years

3. Pregnancy

4. Contraindications to regional anesthetic including but not limited to:

   1. Patient refusal to regional field blockade
   2. Allergy
   3. Infection at the site of needle insertion
   4. Systemic infection
   5. Bleeding diathesis or coagulopathy (as diagnosed by history or laboratory evaluation)
   6. Liver or renal disease (SCr > 1.5)

5. Chronic opioid use