The Use of Laparoscopic Transversus Abdominis Plane Block in Gastric Bypass Surgery (LapTAP)

Randomized, Double-Blinded, Placebo-Controlled Trial of Laparoscopic Transverse Abdominis Plane (Lap TAP) and Rectus Sheath Block in elective Gastric Bypass Surgery aiming to evaluate the benefit of a laparoscopically -guided, surgical transversus abdominis plane (TAP) block and rectus sheath block in reducing post-operative opioid consumption and improving outcomes in patients undergoing laparoscopic gastric bypass surgery. The results of this study will provide further evidence on the optimal means to obtain analgesia in patients undergoing gastric bypass surgery

Management of post-operative pain remains a major challenge and an area of continued research. Effective pain control, apart from providing general patient comfort, is critical for a variety of clinical reasons. It leads to early ambulation and improved respiratory function, which significantly reduces the risk of post-operative complications such as pulmonary embolus or pneumonia, as well as early discharge.

Post-operative pain management was typically opioid-based; however, post-operative opioid use may be associated with increased risk of respiratory depression and sedation. It is therefore desirable to implement opioid sparing multimodal analgesia to achieve satisfactory pain control while reducing post-operative opioid requirements and their side-effects.

Rational pain management is a particularly pertinent issue in the patients with morbid obesity (MO). The pathophysiology of obesity, the high prevalence of obstructive sleep apnea, and high susceptibility to respiratory depression amongst patients with MO make safe analgesic (pain) management especially difficult. These individuals are at high risk of post-operative adverse respiratory events, nosocomial infections, cardiovascular complications, and pulmonary emboli (the second leading cause of death in the bariatric surgery population).

Given the increasing number of patients with MO presenting for elective weight loss surgery, it is important to understand and optimize the analgesic requirements of this patient population. However, there are limited evidence-based recommendations and no ideal analgesic regimen exists for patients with MO. Current recommendations include use of step-wise severity-based opioid- sparing multimodal analgesia. It is possible that including local anesthetic blocks will further reduce pain, opioid analgesic consumption and side-effects from pain management (sedation, confusion, nausea \& vomiting etc.) at-risk patient population.

Eligibility Criteria:
Inclusion Criteria:

* Patients undergoing Roux-en-Y gastric bypass surgery;
* Patients who able to tolerate general anesthetic and pneumoperitoneum;
* Patients who able to provide informed consent for the surgery;
* Patients over the age of 18 years;

Exclusion Criteria:

* Patient undergoing planned sleeve gastrectomy (intra-op conversion to sleeve gastrectomy after delivery of Ropivacaine/placebo will be included and analyzed using intention-to-treat approach)
* Patients with an allergy to local anesthetics
* Patients with severe underlying cardiovascular disease (ie: congestive heart failure, conduction abnormalities, and ischemic heart disease)
* Patients with chronic renal disease Stage 3 or greater (Creatinine clearance less than 60mL/min)
* Patients with hepatic dysfunction Child-Pugh Class B or C
* Patients with previous foregut surgery including esophageal, gastric, liver, and pancreas resections
* Patients weighing less than or equal to 100 kilograms as measured in the pre-admission unit
* Patients enrolled in any other study involving involve tissue biopsy.
* Patients with Chronic Pain and Chronic Opioid use- Oral Morphine Equivalent of \>100mg/day