Comparing PIEB and CEI for Labor Pain Relief

This study is a prospective, randomized controlled trial conducted at the Labor and Delivery Unit of Family Hospital, Da Nang. The investigation focuses on the clinical advantages of automated high-pressure bolus delivery (PIEB) compared to constant low-pressure flow (CEI) in optimizing the spread of local anesthetics within the epidural space. Clinical Procedures: All participants receive a standardized initial manual bolus of 10 mL (0.1% Ropivacaine and 2 mcg/mL Fentanyl) to establish a baseline sensory block. Following this induction, patients are managed according to their assigned study arm: PIEB Group: Analgesia is maintained using a programmed pump set to deliver an automated bolus of 8 mL every 60 minutes, starting one hour after the initial dose. CEI Group: Analgesia is maintained via a continuous infusion of the same anesthetic solution at a constant rate of 8 mL/hour. Analgesia Management and Rescue Protocol: Both groups have access to PCEA, allowing for self-administered 5 mL boluses with a 10-minute lockout period, capped at a maximum of 20 mL per hour. To ensure maternal comfort, a standardized rescue protocol is strictly followed: if the Visual Analog Scale (VAS) score remains \> 4 after two consecutive PCEA demands, a manual rescue bolus of 5 mL is administered by the anesthesia team.