Intraperitoneal Instillation of Local Anesthetic (IPILA) in Bariatric Surgery and the Effect on Post-operative Pain Scores: a Randomized Control Trial.

Background: Effective analgesia after bariatric procedures is vital as it can reduce post-operative opioid use. This leads to less nausea which may be associated with shorter post-operative length of stay (LOS). Understanding analgesic requirements in patients with obesity is important due to the varied physiology and increased number of comorbidities.

Objectives: The aim of this study was to evaluate the efficacy of intraperitoneal instillation of local anesthetic (IPILA) to reduce opioid requirements in patients undergoing laparoscopic bariatric surgery.

Methods: A double-blinded randomized control trial was conducted to compare intraperitoneal instillation of ropivacaine to normal saline in 104 patients undergoing bariatric surgery. The primary endpoint was pain in recovery with secondary endpoints at 1, 2, 4, 6, 24, and 48 h post-operatively. Further endpoints were post-operative analgesic use and LOS. Safety endpoints included unexpected reoperation or readmission, complications, and mortality.

Results: There were 54 patients in the placebo arm and 50 in the IPILA. Pain scores were significantly lower in the IPILA group both at rest (p = 0.04) and on movement (p = 0.02) in recovery with no difference seen at subsequent time points. Equally, IPILA was independently associated with reducing severe post-operative pain at rest and movement (adjusted odds ratio [aOR] 0.28, 95% CI 0.11-0.69, p = 0.007 and aOR 0.25, 95% CI 0.09-0.62, p = 0.004, respectively). There was no significant difference in LOS, opioid use, antiemetic use, morbidity, or mortality between the intervention and placebo groups.

Conclusion: The administration of ropivacaine intraperitoneally during laparoscopic bariatric surgery reduces post-operative pain in the recovery room but does not reduce opioid use nor LOS.