TAP Block for Laparoscopic Appendicectomy in Adults
TAP Block for Laparoscopic Appendicectomy in Adults
Laparoscopic (key-hole) appendicectomy 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. Opioids are associated with an increased incidence
 of nausea, vomiting and sedation which can complicate post-operative recovery. Different
 techniques of intraoperative infiltration of local anaesthetic to control postoperative pain
 are also being used. Their perceived benefits are thought to relate to reduced opioid
 consumption and therefore reduced opioid side effects.

 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, a reduction in post-operative nausea and vomiting 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 the investigator's hospital.
Summary of Study Design: The study will be a double blind randomised controlled trial with
 patients undergoing laparoscopic appendicectomy randomly allocated into two groups. The study
 group will receive bilateral TAP blocks and the control group will receive local anaesthetic
 infiltration of the laparoscopic port sites

 A double blind design was chosen to eliminate patient and observer bias in reporting of pain
 scores.

 The presence of the control arm will ensure that any difference observed will be due to the
 effect of sensory nerve block due to the TAP block than due to the systemic effect of the
 injected local anaesthetic.

 The null hypothesis will be that there is no difference between the groups in the amount of
 opioids consumed by the patients during 24 hours after the operation. The investigators chose
 this measurement as an objective but indirect measurement of efficacy of TAP block and pain
 relief thus received. Measurement of pain with various scoring methods are reliable only when
 concurrent reduction in consumption of pain killers are demonstrated.

 Recruitment and randomisation:

 All patients meeting the inclusion criteria will receive a patient information leaflet about
 the study during the procedure and investigators will gain informed consent during the
 procedure consultation. Investigators aim to recruit 288 patients with 144 patients in each
 group.

 Informed consent will be taken the evening before, or on the morning of, surgery. Patients
 will then be randomly allocated into either the study group or a control group. Randomisation
 will occur by using computer generated random numbers using the block randomisation method.
 Group allocation will be kept in a consecutively numbered, opaque, sealed envelope in the
 controlled drugs cupboard in theatre-4/emergency theatre anaesthetic room of the John
 Radcliffe Hospital. Once the patient has consented, the anaesthetist will open the
 corresponding numbered envelope and perform bilateral TAP blocks after induction of general
 anaesthesia if the patient is in the study group. The surgeons will infiltrate the port sites
 with local anaesthetic at the end of the procedure if the patient is in the control group.

 Blinding:

 The study group will receive bilateral TAP blocks with 20mls 0.25% bupivacaine on each side
 and the skin punctures on either sides will be covered with a small plaster. Patients in the
 control group will receive subcutaneous infiltration of the laparoscopic port sites and
 specimen extraction site with equivalent amount bupivacaine at the end of the procedure and
 small plasters will be stuck on either flanks approximately where the skin punctures for TAP
 block will be made.

 The assessor of pain scores and morphine doses (Recovery nurse, Ward Nursing Staff & SEU
 Foundation Doctor) and the patient will be blinded to group allocation.

 Patient: Plasters will be stuck on flanks of all the patients, both study and control group,
 so that patient will not know if they have received TAP block.

 Recovery nurse: During handover to recovery the anaesthetist and scrub nurse will not mention
 group allocation.

 SEU Foundation Doctor: The foundation doctor who will be following up patients on the ward
 will not be present in the operating theatre, ensuring that they are blinded to the technique
 used.

 The study duration will be from induction of anaesthesia until the patients are medically fit
 for discharge from hospital. No extra visits other than routinely required for the surgical
 procedure are expected.
Inclusion Criteria:

 -  Participants willing and able to give informed consent for participation in the study

 -  Male or Female, aged 16 years or above

 -  Undergoing laparoscopic appendicectomy for a clinical diagnosis of appendicitis

 -  American Society of Anaesthetists physical status (ASA) 1-3

 Exclusion Criteria:

 -  Opioid tolerance

 -  Chronic abdominal pain

 -  Allergy/Intolerance: Morphine, local anaesthetics, tramadol

 -  BMI (Body Mass Index) >35 Kg/M2

 -  Previous major abdominal surgery

 -  High likelihood of conversion of open procedure

 -  Patients unable to communicate in written and spoken English

 -  Weight less than 50 kg

 -  ASA > 3