Comparison of Intrathecal Morphine With the Quadratus Lumborum Type 2 Block for Post-operative Analgesia Following Elective Caesarean Section (QLBvITM Study)

Quadratus Lumborum Type 2 Block Versus Intrathecal Morphine for Analgesia Following Elective Caesarean Sections

The investigators are comparing post operative analgesia provided for caesarean section patients, with the quadratus lumborum type 2 block and intrathecal morphine.

In Australia the rate of birth via caesarean section (CS) has significantly increased over the last twenty years. Improvements in the care of women undergoing CS are important locally, nationally and internationally. Compared to women birthing vaginally, women undergoing CS experience more adverse events and more pain. Effective pain relief following CS is important as it enables early ambulation, encourages maternal bonding, and promotes breastfeeding initiation and establishment. Traditional analgesic techniques following CS include opioid medications. Whist effective, the use of opioids are associated with frequent and significant side effects. Alternative analgesic agents are being explored in an attempt to improve the effectiveness of pain relief available to women and clinicians.

The quadratus lumborum block (QLB) block is an innovative regional analgesic technique. Its role as an effective analgesic agent in abdominal surgery is increasing. However, it has not been studied for pain relief in Australia after cesarean section.

In this study, the investigator aims to compare post-operative analgesia and side effects between the QLB blocks versus adding morphine the participant's spinal anaesthetic (ITM) during the elective C/S. Results from this study will provide information on the analgesic impact of this new and emerging therapy and assist in the development of a larger clinical trial.

Inclusion Criteria:

• Anaesthetist trained in QLB and ITM techniques available
• American Society of Anaesthesiologists PS category client I or II
• 18 years of age or older
• Ability to read and understand English
• Uncomplicated pregnancy at term (>37 weeks completed gestation)
• Booked elective CS

Exclusion Criteria:

• Contraindications to spinal anaesthesia
• History of chronic opioid consumption / chronic pain conditions
• Known allergy to study drugs
• Weight more than 95kg or body mass index (BMI) more than 35 pre operative
• Placenta Previa / accreta
• Obstructive Sleep apnoea
• Severe asthma unable to tolerate Non steroidal anti inflammatory agents