Background: Dexmedetomidine is known to prolong the analgesic duration of spinal anesthesia, but it can be challenging to achieve further extension without opioids. Therefore, this study aimed to investigate a novel analgesic strategy using dexmedetomidine as an adjuvant to spinal-epidural anesthesia for elective cesarean surgery. Methods: The study was a randomized, double-blind, controlled trial conducted at a single center. Sixty parturients who underwent elective cesarean were randomly assigned to either group C or group D. Group D received an intrathecal injection of 12.5 mg ropivacaine and 5 µg dexmedetomidine followed by continuous epidural patient-controlled analgesia (PCA) infusion with a total volume of 100 ml, containing 0.2 % ropivacaine and 0.5 µg/kg dexmedetomidine. Group C received an intrathecal injection of 12.5 mg ropivacaine with an equivalent saline placebo followed by a similar PCA infusion, containing 0.2 % ropivacaine and an equivalent saline placebo. Results: The primary outcome was visual analog scale score on movement at 24 h after surgery. The results showed that the rest and motion pain scores in group D were significantly lower than those in group C at 6 h, 12 h, and 24 h after surgery (P < 0.05), with the differences at 24 h were 5.0 (5.0, 5.0)in group D versus 5.0 (5.0, 6.0) in group C (P = 0.04). Additionally, the time to the first PCA in group D was significantly longer than that in group C (P < 0.05), as well as the time of sensory and motor recovery. Conclusions: Whole-course application of dexmedetomidine as an adjuvant to spinal-epidural anesthesia could effectively extend the analgesic duration of ropivacaine to 24 h following elective cesarean surgery.
