Comparing epidural surgical anesthesia and spinal anesthesia following epidural labor analgesia for intrapartum cesarean section: a prospective randomized controlled trial

BACKGROUND The conversion of epidural labor analgesia (ELA) to epidural surgical anesthesia (ESA) for intrapartum cesarean section (CS) often fails, resulting in intraoperative pain. Spinal anesthesia (SA) can provide a denser sensory block than ESA. The purpose of this prospective, non-blinded, parallel-arm, randomized trial was to compare the rate of pain-free surgery between ESA and SA following ELA for intrapartum CS. METHODS Both groups received continuous epidural infusions for labor pain at a rate of 10 ml/h. In the ESA group (n = 163), ESA was performed with 17 ml of 2% lidocaine mixed with 100 µg fentanyl, 1 : 200,000 epinephrine, and 2 mEq bicarbonate. In the SA group (n = 160), SA was induced with 10 mg of 0.5% hyperbaric bupivacaine and 15 µg fentanyl. We investigated the failure rate of achieving pain-free surgery and the incidence of complications between the two groups. RESULTS The failure rate of achieving pain-free surgery was higher in the ESA group than the SA group (15.3% vs. 2.5%, P < 0.001). There was no statistical difference between the two groups in the rate of conversion to general anesthesia; however, the rate of analgesic requirement was higher in the ESA group than in the SA group (12.9% vs. 1.3%, P < 0.001). The incidence of high block, nausea, vomiting, hypotension, and shivering and Apgar scores were comparable between the two groups. CONCLUSIONS SA after ELA can lower the failure rate of pain-free surgery during intrapartum CS compared to ESA after ELA.