Despite the increasing use of patient-controlled anesthesia (PCA) for postoperative pain management, efforts are continuing to find effective methods to relieve pain after abdominal surgery. Although opioid is an effective analgesic it has opioid related adverse events (ORAEs). Bupivacaine should reduce postoperative pain but it has relatively shorter duration of action. Liposome bupivacaine (Exparel) has been approved as a single dose infiltration for longer postoperative period analgesic. It provides up to 72 hours analgesia postoperatively; results in lesser opioids usage and reduce the ORAEs. Transversus abdominis plane (TAP) block is a relatively new regional anesthetic technique. TAP blocks have been performed to reduce opioid use and control pain in several laparoscopic surgical procedures, including colorectal resections, cholecystectomy and bariatric surgery. The aim of this study is to study the opiate usage, pain and nausea post laparoscopic gastric bypass or sleeve gastrectomy using Exparel versus Bupivacaine as TAP block and port sites infiltration.

Introduction

Despite the increasing use of patient-controlled anesthesia (PCA) for postoperative pain management, efforts are continuing to find effective methods to relieve pain after abdominal surgery. Some studies have already suggested that infusion with local anesthetics at the wound site can decrease postoperative pain levels. Further, other studies have shown equal amounts of opiate analgesic requirements (administered on patient demand) with placebo and local anesthetic administration. However, varying anesthetic administration techniques used in the different studies may explain why the controversy in the literature exists.

Although opioid is an effective analgesic it has opioid related adverse events (ORAEs). Bupivacaine should reduce postoperative pain but it has relatively shorter duration of action. Liposome bupivacaine (Exparel) has been approved as a single dose infiltration for longer postoperative period analgesic. It provides up to 72 hours analgesia postoperatively; results in lesser opioids usage and reduce the ORAEs.

Transversus abdominis plane (TAP) block is a relatively new regional anesthetic technique that targets blockage of the neural afferent of the lower intercostal, iliohypogastric and ilioinguinal nerves in the neurovascular plane between the internal oblique and the transversus abdominis muscle. TAP blocks have been performed to reduce opioid use and control pain in several laparoscopic surgical procedures, including colorectal resections, cholecystectomy and bariatric surgery.

Efficacy of wound infiltration with or without TAP block using immediate-release bupivacaine HCl for acute postsurgical pain is well established; EXPAREL has been proposed as a method for postoperative pain management. Moreover, the administration and the optimal dosage in the bariatric surgical population have not been studied.

The objective of this study is to examine postoperative pain after laparoscopic gastric bypass with TAP block and port sites infiltration using Exparel versus Bupivacaine

Background and significance

Exparel is a FDA approved long-acting, local anesthetic. This is for single-dose infiltration into the surgical site to produce postsurgical analgesia. Exparel offers longer-acting local formulation and can be administered as a single dose. Exparel has a longer duration of action with slower absorption. The mean elimination half-life of local administration of Exparel is approximately 24-34 hours 19-20 versus 2.7 hours for bupivacaine.

Liposomal bupivacaine is for single-dose infiltration and the recommended dose depends on the surgical site but the maximum dose of liposomal bupivacaine is 266 mg and it is injected into soft tissues of the surgical site with frequent aspirations to prevent intravascular injection.

A pooled analysis evaluating the effect of Exparel on pain intensity scores and opioid consumption was published by Dasta et al. This study included 5 surgical procedures (inguinal hernia repair, total knee replacement, hemorrhoidectomy, breast augmentation and bunionectomy) comparing Exparel with bupivacaine HCl, on 912 patients; it showed significantly lower pain score and opioid usage, delayed use of rescue opioid and reduced ORAEs in the Exparel group; as compared to bupivacaine HCL group.

Medication SafetLiposomal bupivacaine has been classified as a high-alert medication by the Institute of Safe Medication Practices due to its similar appearance to propofol. If liposomal bupivacaine were administered intravenously as if it were propofol, adverse cardiac effects may result.

Hypothesis

Exparel (1.3%) and 0.5% Bupivacaine usage with infiltration and TAP block decreases opiate usage, nausea and pain at 48 hours as compared to 0.5% Bupivacaine only.

Primary Objective of the study:

To study the opiate usage, pain and nausea post laparoscopic gastric bypass or sleeve gastrectomy using EXPAREL versus Bupivacaine as TAP block and port sites infiltration.

Inclusion Criteria:

• Fulfills NIH criteria for bariatric surgery
• Planned operation of laparoscopic Roux-en Y gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG) as primary bariatric procedure

Exclusion Criteria:

• BMI <35 and > 60 kg/m2

• Inability to walk (bed-bound or wheelchair dependence)

• Previous major abdominal surgery (possible adhesions and longer operation) defined as:

  • open abdominal surgeries except simple appendectomy and common OB/GYN procedures in the pelvis (hysterectomy, C-section, and oophorectomy, tubal ligation)
  • laparoscopic bowel or solid organ resection except laparoscopic cholecystectomy
  • ventral hernia repair with mesh

• Preoperative chronic opiate use for chronic pain defined as opiate usage at least 60 mg/day of morphine equivalent for ≥ 3 months (as defined by International Association for the Study of Pain22) in the one year period prior to the bariatric surgery

• The American Society of Anesthesiologists (ASA) score > 3

• History of hypersensitivity or adverse reaction to bupivacaine or narcotics

• Inability to speak English

• Concurrent surgical procedure including:

  • ventral hernia repair
  • Cholecystectomy
  • hiatal hernia repair with posterior cruroplasty
  • extensive lysis of adhesions
  • other procedures that mandate addition of "trocar(s)" or "feeding tube"

• Addition of trocar(s) or conversion of surgery to hand-assisted or open

A total of 101 patients were included; Bupivacaine alone (n=50) and Liposome bupivacaine and bupivacaine (n=51) with a follow up period of 1-month.

Two patients in the study arm developed urticarial rashes over the abdominal wall at the site of injection. Their rashes were noticed on day 7 after the procedure during follow up visit in the clinic by the attending physician.

Two patients in the study arm developed urticarial rash over the abdominal wall at the site on injection noticed at 1 week post procedure during follow up visit. The rash noticed at 1 week post procedure during follow up visit. The rash was itchy but limited only to the abdominal area at the injection site.

No other adverse events noted. At subsequent follow up, the rash has resolved.

There is no data available to guide us on the dosage of liposome bupivacaine in bariatric surgery. We assume adequate quantity and coverage of liposome bupivacaine (266mg) in this obese population, despite that they have a bigger surface area.