Date of Award


Degree Name

Masters of Medicine/Masters of Surgery

Schools and Centres


First Supervisor

Nicholas Williams

Second Supervisor

Alexa Seal

Third Supervisor

Igor Lemech


Effective analgesia during bariatric procedures may be vital as it could reduce post-operative opioid use. This can lead 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.

The aim of this study was to evaluate the efficacy of IntraPeritoneal Instillation of Local Anaesthetic (IPILA) to reduce opioid requirements in patients undergoing laparoscopic bariatric surgery.

A double-blinded randomised 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 hrs post-operatively. Further endpoints were post-operative analgesic use and LOS. Safety endpoints included unexpected reoperation or readmission, complications and mortality.

There were 54 patients in the placebo arm and 50 in 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 postoperative 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.

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.

Key Words
Bariatric surgery, intraperitoneal instillation, ropivacaine, post-operative pain

Key Points

• Intraperitoneal local anaesthetic reduces severe post-operative pain in the recovery room

• There is no change in post-operative pain beyond 1 hour

• There is no change in overall use of opioids nor length of stay