Transversus Abdominis Plane (TAP) Block for Postoperative Analgesia After Laparoscopic Colonic Resection

Laparoscopic (key-hole) large bowel resection is a minimally invasive procedure when compared to open large bowel resection, but is still associated with a significant amount of pain and discomfort. Analgesia is commonly provided by a multi-modal technique involving varying combinations of paracetamol, Non steroidal anti-inflammatory drugs (NSAIDs), regional analgesia and oral or parenteral opioids. While epidural analgesia is considered the gold standard for open colo-rectal procedures it can be associated with significant complications and may delay hospital discharge in laparoscopic procedures. Opioids are associated with an increased incidence of nausea, vomiting and sedation and reduced bowel motility which can also prolong recovery. Transversus Abdominis Plane (TAP) block is a technique which numbs the nerves carrying pain sensation from the abdominal wall and provides effective and safe analgesia with minimal systemic side effects. Their perceived benefits are thought to relate to reduced opioid consumption and therefore reduced opioid side effects. The investigators believe ultrasound guided TAP blocks will reduce pain and morphine consumption with a resultant improved patient satisfaction, earlier return of bowel function and earlier hospital discharge. The key research question the investigators are trying to answer is whether TAP block provide better pain relief than local anaesthetic infiltration of the laparoscopic port sites. Both techniques are currently being used in our hospital and a retrospective audit demonstrated better analgesia and lower consumption of morphine in the TAP block group.The differences were not statistically significant as the number patients in the audit were not large enough.The investigators are hoping that this study will demonstrate that the difference is real by recruiting the necessary number of patients into each group (36 per group)