Effects of immediately initiating an epidural infusion in the combined spinal and epidural technique in nulliparous parturients

Background and Objectives: Intrathecal fentanyl with bupivacaine provides rapid labor analgesia of limited duration. We investigated the effect of initiating an epidural infusion of 0.1% ropivacaine with fentanyl 2 μg/mL and epinephrine 1:400,000 (REF) on the duration of analgesia and incidence of side effects after intrathecal injection in the combined spinal and epidural technique. Methods: Thirty-four nulliparous parturients with a cervical dilation of 3 to 5 cm were randomized to receive epidural saline or REF at 10 mL following the intrathecal injection of fentanyl 25 μg and bupivacaine 2.5 mg. Degree of analgesia, severity of pruritus, motor block, blood pressure, and sensory level to coolness were assessed until the patient requested additional analgesia. Results: Analgesia was significantly longer in the REF group, 158.4 ± 59.6 minutes versus 103.8 ± 26.2 minutes. The decrease in blood pressure compared with the blood pressure at intrathecal injection was greater for the REF group at all times, but achieved statistical significance at 60 minutes. There was no difference in ephedrine use, pruritus, or motor block between groups. There was no difference in sensory level to coolness at 90 minutes after intrathecal injection between groups. Conclusions: Initiating an infusion of REF prolongs the duration of analgesia, but also results in a greater decrease in blood pressure. Despite this effect on blood pressure, there was no difference in ephedrine use.