Comparison of Different Methods of Pain Control After Cesarean Section for Patients on Buprenorphine or Methadone

Comparison of Transversus Abdominis Plane Block Versus Patient-controlled Epidural Analgesia for Patients on Buprenorphine or Methadone, After Cesarean Section

More and more women are on buprenorphine or methadone during pregnancy for a history of opioid addiction. Currently, pain control after cesarean section for women already on these medications, if they need operative delivery, is a challenge due to the pharmacology of those drugs. They have higher pain scores and 45-47% higher opiates requirement. To improve pain control, some unique regional anesthesia techniques have been employed, besides opioid and non-opioid medication management through the oral, intravenous, and/or neuraxial (spinal or epidural) route. One is a TAP block ( transversus abdominis plane block), a regional anesthesia procedure in which long acting local anesthetic, such as ropivacaine, is injected on both sides of the patient's abdomen to numb the nerves supplying the abdominal wall, or the surgical site. Another is a patient - controlled epidural, a small flexible catheter that is inserted in the back into the epidural space near the spine, which bathes the spinal nerve roots with long acting local anesthetic, such as bupivacaine, and with an opioid, such as fentanyl, to numb the nerves going to the surgical site. Through an epidural pump, the patient receives a continuous infusion of local anesthetic and can delivery more medication as needed through a bolus feature. There have case reports, or case by case accounts, of these techniques, and it is suspected these techniques result in better pain control with minimal side effects. No clinical, human or animal, has evaluated these techniques in a controlled and through manner, either comparing the two techniques to each other or comparing them to the common care of opioid and non-opioid medication management through the oral, intravenous, and/or neuraxial route, including neuraxial hydromorphone or morphine.

Inclusion Criteria:

• Anesthesiology Society of Anesthesiologist's Status of II or III
• Maintenance methadone or buprenorphine during pregnancy
• Regional anesthesia staff to perform a TAP block
• Elective, non-urgent cesarean delivery via a Pfannenstiel incision under regional anesthesia

Exclusion Criteria:

• Emergency cesarean section
• Laboring patients who are now having to delivery operatively
• Patients with a BMI over 50
• Patients with allergies to any of the study medications
• Patients under 18 years old
• Patients with multiple gestations
• Patients undergoing general anesthesia
• Patients who had contraindications for either an epidural or a TAP block as in coagulopathies, chronic back pain, skin conditions, or existing neuropathies
• Patients who cannot understand the use of a patient controlled epidural analgesia