This clinical trial aims to determine the optimal timing for administering a Transversus Abdominis Plane (TAP) block in bariatric surgery, specifically investigating whether initiating TAP blocks at the beginning of surgery is more beneficial than at the end, which is the current practice. The study targets obese patients undergoing bariatric surgery, with a focus on reducing postoperative pain and opioid use. Key outcomes include recovery duration, pain levels, opioid consumption, and respiratory function. Successful results could establish early TAP block initiation as a standard practice, offering faster recovery, decreased opioid reliance, and reduced healthcare costs.

Post-operative pain remains a critical aspect of patients' recovery, with approximately 70% of patients who undergo surgery reporting moderate to severe levels of pain post-operatively. Increased post-operative pain has adverse effects on psychological and physiological function including cardiovascular, respiratory, gastrointestinal, immune function and wound healing. In an era where patient centered care is at its peak and healthcare resources are limited, adequate post-operative pain management is crucial. It facilitates early mobilization, reduces the length of stay in hospital and overall costs on the healthcare system.

The transversus abdominis plane (TAP) block, a peripheral nerve block, has been shown to significantly reduce postoperative opioid requirements, even in the context of minimally invasive surgery (MIS). Furthermore, the literature clearly indicates the benefit of TAP blocks on post-operative analgesia in patients undergoing bariatric surgery. However, evidence regarding the ideal timing of TAP block administration in the bariatric population is lacking. In current practice, TAP blocks are generally administered after the surgery, and occasionally after induction of anesthesia. However emerging studies suggest that administering TAP blocks at the beginning of a procedure may result in superior recovery and pain control in the immediate period following open and laparoscopic surgery compared to at the end of a procedure.

The purpose of the study is to assess the timing of TAP block administration in bariatric surgery patients on the immediate post-operative recovery period. This will be determined by the amount opioids required in the post-anesthetic recovery unit (PACU). Post-operative pain increases the incidence of nausea/vomiting, oxygen requirements and thus, consequently becoming a major barrier to recovery. If found to be effective, post-induction TAP blocks could become the standard of care for regional anesthesia following laparoscopic bariatric surgery and could reduce intra-operative anesthetic and opioid use, opioid consumption in (PACU), post-operative nausea and vomiting and overall length of stay in PACU. This in turn will improve patient's recovery, reduce delays in PACU and decrease patient's length of stay in the hospital.

Inclusion Criteria:

• Patients undergoing primary bariatric surgery at St. Joseph's Healthcare Hamilton surgery including Sleeve Gastrectomy (SG) or Roux-en-Y Gastric Bypass Surgery (RYGB)
• Patients >18 Years of Age

Exclusion Criteria:

• Patients undergoing a revisional bariatric surgery
• Patients with a history of chronic pain or opioid use.