The Use of Intraperitoneal Ropivacaine in Bariatric Bypass Surgery

A Pilot Study to Assess the Feasibility of a Future Randomized, Double-Blinded, Placebo-Controlled Trial to Investigate the Role of Intra-Peritoneal Ropivacaine in Gastric Bypass Surgery: INOPAIN Trial

This is a pilot study in a randomized, controlled, double-blinded format and will evaluate the ability of a local anesthetic, Ropivacaine, to decrease pain after gastric bypass surgery. The drug will be administered into the abdomen during a bariatric bypass surgery. After surgery, patients who received Ropivacaine will be compared to those without Ropivacaine to determine its effect on reducing pain, recovery of lung function, ability to walk, and quality of life during recovery.

Introduction: Postoperative pain control remains a major challenge for surgical procedures, including laparoscopic gastric bypass. Pain management is particularly relevant in obese patients who experience a higher number of of cardiovascular and pulmonary events. effective pain management may reduce their risk of serious postoperative complications, such as deep venous thrombosis and pulmonary emboli. The objective of this study is to evaluate the efficacy of intraperitoneal local anaesthetic, ropivacaine, to reduce postoperative pain in patients undergoing laparoscopic Roux-en-Y gastric bypass.

Methods and Analysis: A randomized controlled trial will be conducted to compare intraperitoneal ropivacaine (Intervention) versus normal saline (placebo) in 120 adult patients undergoing bariatric surgery. Ropivacaine will be infused over the oesophageal hiatus and throughout the abdomen. Patients in the control arm will undergo the same treatment as normal saline. The primary end point will be postoperative pain at 1, 2 and 4 hours postoperatively. Pain measurements will then occur every 4 hours for 24 h and every 8h until discharge. Secondary endpoints will include opioid use, peak expiratory flow, 6 min walk distance and quality of life. Intention-to-treat analysis will be used and repeated measures will be analysed using mixed model approach. post-hoc pairwise comparison of the treatment groups at different time points will be carried out using multiple comparisons with adjustments to the type 1 error. Results of the study will inform the feasibility of effectiveness of intraperitoneal ropivacaine.

Ethics and dissemination This study has been approved by the Ottawa Health Science Network Research Ethics Board and Health Canada in April 2014. The findings of the study will be disseminated through national and international conferences and peer-reviewed journals.

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 (inta-op conversion to Sleeve Gastrectomy after delivery of intraperitoneal ropivacaine 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/hr (millilitre per hour))
• Patients with hepatic dysfunction Child-Pugh Class B or C
• Patients with previous foregut surgery including esophageal, gastric, liver, and pancreas resections