A prospective comparison of early post-operative analgesia in Caesarean Section using bilateral ilio-inguinal block and sub-cutaneous morphine

Anaesthesia for Caesarean Section is most often performed by an injection of intra-thecal (spinal) or epidural local anaesthetic. This wears after 2-4 hours after which pain needs to be controlled with other agents. The principal class of drugs used for this analgesia are the opioid drugs (eg. oxycodone, codeine or morphine), all of which cause side effects such as nausea, vomiting, itch and sedation. Bilateral ilio-inguinal blocks (superficial injections on each side of the abdominal wall) have been shown to be effective after general anaesthetic in reducing opioid requirements after Caesarean Section. They are also used routinely for procedures such as inguinal hernia repair. We propose to recruit 120 patients undergoing elective Caesarean Section and randomise them to receive ilio-inguinal blocks with either ropivacaine (a long acting local anaesthetic) or saline (placebo). Those who receive placebo blocks will be given subcutaneous morphine at the end of the procedure (the current standard care). We will review patients at 6 and 24 hours seeking a decrease in pain scores, opioid requirements and opioid side effects.