Effect of different doses of epidural dexmedetomidine on reducing visceral traction reaction for cesarean section: a double-blind randomized controlled trial

Abstract

Purpose: This study aimed to evaluate the effect of different doses of epidural dexmedetomidine on reducing visceral traction reaction for cesarean section under epidural anesthesia.

Methods: Nulliparas were randomly allocated to receive epidural ropivacaine alone (group R) or in combination with dexmedetomidine 0.5 μg/kg (group RD0.5), 0.75 μg/kg (group RD0.75), and 1 μg/kg (group RD1) with 46 nulliparas in each group. The primary outcome was intraoperative visceral traction reaction (graded from 0 to 3, with 0 and 3, respectively, regarded as 'no discomfort in stomach or perineum; no nausea, vomiting or intestinal tympanites' and 'serious visceral pain, nausea and vomiting, intestinal tympanites').

Results: Visceral traction reaction was significantly alleviated in group RD0.5, RD0.75, and RD1, respectively, compared to group R while it was comparable among RD groups. Increased Ramsay Sedation Scale and lower incidence of shivering were found in RD groups compared to group R (p < 0.001). None of the primipara has experienced Ramsay Sedation Scale above 4. Higher incidence of thirst was found in group RD0.75 and RD1 compared to group R and RD0.5 (p < 0.001). The Apgar scores at 1 and 5 min of the neonates, onset time to T6 sensory block, maximum sensory block level, the incidence of hypotension, bradycardia and nausea or vomiting were comparable among groups.

Conclusion: It is suggested that 0.5 μg/kg epidural dexmedetomidine can be used as adjuvant to epidural ropivacaine during cesarean section, because of its alleviating visceral traction reaction, moderate sedating, and reducing shivering without thirst increase.

Keywords: Cesarean section; Dexmedetomidine; Epidural anesthesia; Nullipara; Visceral pain.