Comparing 2 Types of Pain Relief After Cesarean Delivery: Spinal Morphine and TAP Block
Condition: Cesarean Delivery
Study type: Interventional

Summary: 
      Summary Brief Summary Standard care for pain relief after cesarean delivery is spinal
      morphine. Spinal morphine may be unsuitable for patients having general anesthetic or prior
      morphine-related side effects and can be less effective in patients with morphine tolerance.
      An alternative is a TAP block where local anesthetic is deposited between the abdominal
      muscles consequently numbing the area and providing pain relief. The investigators believe a
      TAP block will provide equivalent pain relief to spinal morphine.
    

Detailed description: 
      Detailed Description In North America, the standard of care is neuraxial morphine. This is an
      effective analgesic, but can still cause problems with nausea, vomiting and itching. Spinal
      morphine may be unsuitable for patients who have had morphine-related side effects in the
      past and can be less effective in patients with morphine tolerance. It is also poorly suited
      for patients who have had a general anesthetic, as anesthesiologists do not routinely access
      the spinal space purely for analgesia. It is only when they are using the spinal route for
      surgical anesthesia, that they will also deposit morphine to provide pain relief after
      surgery.

      The abdominal wall incision is an important contributor to pain following a cesarean
      delivery. The nerves supplying the anterior abdominal wall between the internal oblique and
      transversus abdominis muscles. By depositing local anesthetic solution between these muscles
      on each side, it is possible to block all these nerves and provide analgesia for the incision
      of the anterior abdominal wall. This is known as the transversus abdominis plane block or TAP
      block.

      Studies have shown the TAP block to be useful for midline laparotomies for open
      prostatectomies, bowel resection and as rescue analgesia for abdominal surgery. There are two
      studies which look specifically at TAP block after cesarean delivery but none of them have
      compared it directly the current standard.

      This study is a direct comparison of spinal morphine and TAP block. Obviously, adequate
      analgesia is of paramount importance to the patient and those caring for her. Studies to date
      indicate that the TAP block provides similar analgesia to spinal morphine in the early
      post-operative period. Therefore it would be a reasonable alternative for those patients who
      cannot have spinal morphine or who can not tolerate spinal morphine due to its side effects.

      The primary objective will be to investigate whether the tranversus abdominis plane block
      provides equivalent analgesia post-cesarean delivery, as intrathecal morphine.

      The secondary objective will be to determine whether there is a difference in post-operative
      abdominal scar pain, at three months post-surgery.

      This study will be a prospective, randomized, placebo-controlled, double blinded study.

      The study will involve two groups. Both groups will have spinal anesthesia for the surgery
      provided with 9-12 mg heavy bupivacaine and 10 mcg fentanyl.

        1. Control group: standard care plus a placebo block.

        2. Intervention group: no additional spinal medications will be given and an
           ultrasound-guided TAP Block will be given instead of the standard intrathecal morphine.

      Standard post-cesarean analgesia and PONV orders will be resumed post-delivery.
    

Intervention name(s): Placebo block; Ultrasound-guided TAP block
Intervention type(s): Procedure; Procedure
Intervention description(s): 100 micrograms of spinal morphine; 1.5mg/kg of 0. 5% ropivacaine (to maximum dose of 20 mls = 100mg on each side) will be injected into the transversus abdominis plane, on each side
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Cesarean delivery; post-operative analgesia; TAP block; ultrasound