Chapter 49: Conversion of Labor Epidural for Cesarean Delivery

BACKGROUND

The incidence of intrapartum cesarean delivery (CD) varies between 8% and 20% among different hospitals. Anesthesia for intrapartum CD differs from elective CD because:

• It is often emergent or urgent.

• Usually, the patient has an existing labor epidural rather than a de novo spinal or combined spinal and epidural (CSE).

• Failure rates for conversion of labor epidural analgesia to surgical anesthesia for CD can be as high as 20%.¹

• Postoperative CD analgesia can also be complicated for a patient who has endured both labor pain and CD pain.

Successful conversion of labor epidural analgesia to CD anesthesia is a meaningful measure of quality of care and an important clinical process to reduce the incidence of general anesthesia and ensure maternal comfort during CD.²

The definition of failure of conversion varies greatly in literature resulting in a great difference in the incidence of failure of conversion. Most authors define failed conversion as the need to perform either a repeat neuraxial procedure or general anesthesia.

THE RISKS OF FAILURE OF CONVERSION

The Risks of Failure of Conversion³

• Recurrent breakthrough pain requesting multiple epidural boluses (Odds ratio, OR 3.2)

• Urgency of CD (OR 40.4)

• Long duration of labor epidural

• Nonobstetric anesthesia specialized provider (OR 4.6)

• Second-stage arrest⁴

• Chorioamnionitis⁵

STRATEGIES FOR SUCCESSFUL CONVERSION (FIG. 49-1)

Understanding the reasons for failure will help anesthesiologists strategically plan to achieve a successful conversion. Early and active steps to prevent failure are more desirable than late recognition with the potential need for general anesthesia. The following are suggested:

• Aggressively treat breakthrough pain (Chapter 42, “Refractory Pain During Labor Epidural Analgesia”).

• Replace the epidural catheter early if the sensory level does not improve with repeat boluses.

• If breakthrough pain is refractory to treatment during labor, consider replacing a new CSE in the operating room. A reduced dose of bupivacaine (0.8-1.2 mL of 0.75% hyperbaric bupivacaine) for spinal part is recommended.⁶ Be aware of the risk of high spinal (Chapter 60, “High Spinal”).

• A small dose of epidural dexmedetomidine (10-20 µg) may improve pain control (Chapter 6, “Dexmedetomidine”).

REFERENCES