The 90% Effective Dose of Sufentanil for Epidural Analgesia in the Early First Stage of Labor: A Double-blind, Sequential Dose-Finding Study

Purpose: Epidural analgesia in the latent phase of the first stage of labor has been recognized and accepted by anesthesiologists worldwide. However, there is no unified consensus on the exact dosage of sufentanil with the combination of ropivacaine in the induction of epidural analgesia in the early first stage of labor. In this sequential dose-finding study, the 90% effective dose (ED90) of sufentanil for epidural administration in the early first stage of labor was estimated to minimize the adverse effects of using higher doses. Methods: Forty parturients with cervical dilatation of 2 to 4 cm who requested epidural analgesia were enrolled in this study. Parturients received 15 mL of a combination of ropivacaine 13 mg and the test dose of sufentanil. The initial dose of sufentanil in epidural administration was 1 mu g, and the dose of sufentanil for the next parturient was based on the response of the preceding participant as per a biased coin up-and-down design. The primary outcome was the dose of sufentanil that resulted in successful epidural administration by maintaining the parturients' visual analog scale scores at <= 30 mm in the first 15, 30, and 45 minutes of induction. The ED90 and 95% CIs were estimated using isotonic regression methods and bootstrapping. Findings: The estimated ED90 of sufentanil in epidural administration in the early first stage of labor was 1.91 mu g (95% CI, 1.82-2.35 mu g) in this sequential dose-finding study. (C) 2021 The Author(s). Published by Elsevier Inc.