Intraperitoneal instillation of local anaesthetic (IPILA) in laparoscopic bariatric surgery

INTERVENTION: A prospective double‐blinded clinical randomised control trial will be conducted to compare intraperitoneal instillation of ropivacaine to normal saline in 120 patients undergoing bariatric surgery. The amount of 0.2% ropivacaine used for intra‐peritoneal instillation will be administered according to patient weight at 0.5ml/kg. This will be instilled in and around the esophageal hiatus once at the conclusion of the laparoscopic bariatric procedure. Instillation will occur using a mixing cannula. The amount of ropivacaine will be personalised to each patient by weight to ensure toxic doses are not breached and to accomodate for weight based diffusion variability between patients. The patient's weight will be recorded the day of the intervention and appropriate ml/kg amount of the unidentified drug/saline will be administered. A research nurse will be present to monitor adherence to the specified intervention regimen, CONDITION: Bariatric surgery Obesity Post‐operative pain PRIMARY OUTCOME: Post‐operative pain assessed using the 100mm visual analogue scale SECONDARY OUTCOME: Length of stay post‐operatively which will be assessed by examining patient's hospital records. Morphine consumption or morphine equivalents post‐operatively in mg/kg which will be assessed by examining post‐operative medication charts and patient records. INCLUSION CRITERIA: Patients who are undergoing a laparoscopic bariatric procedure through Riverina Bariatrics