Randomized Assessment of the Optimal Time Interval Between Programmed Intermittent Epidural Boluses When Combined With the Dural Puncture Epidural Technique for Labor Analgesia

BACKGROUND: The dural puncture epidural (DPE) and programmed intermittent epidural bolus (PIEB) techniques are recent advances in neuraxial labor analgesia. Previous studies have investigated the PIEB optimal interval for effective analgesia when a standard epidural technique is used to initiate labor analgesia. However, it is unknown whether these findings are applicable when DPE is used. METHODS: Patients were randomized into 1 of 5 groups with PIEB intervals of 35, 40, 45, 50, or 55 minutes. Labor analgesia was initiated on request with a DPE technique by epidural injection over 2 minutes of 15 mL of ropivacaine 0.1% with sufentanil 0.5 μg/mL after a dural puncture with a 25-gauge Whitacre needle. Effective analgesia was defined as no additional requirement for a patient-controlled bolus during the first stage of labor. The PIEB interval that was effective in 50% of patients (EI50) and 90% of patients (EI90) was estimated using probit regression. RESULTS: One hundred laboring parturients received the DPE technique of whom 93 proceeded to have analgesia maintained with PIEB using 10 mL boluses of ropivacaine 0.1% and sufentanil 0.5 μg/mL. Totals of 89.5% (17/19), 84.2% (16/19), 82.4% (14/17), 52.6% (11/19), and 36.8% (7/19) of patients in groups 35, 40, 45, 50, and 55, respectively, received effective PIEB analgesia. The estimated values for EI50 and EI90 were 52.5 (95% CI, 48.4–62.6) minutes and 37.0 (95% CI, 28.4–40.9) minutes, respectively. CONCLUSION: The estimate of the PIEB optimal interval for effective analgesia after the DPE technique was comparable to that reported in previous studies when analgesia was initiated using a conventional epidural technique.