The Effectiveness and Safety of Intravenous Dexmedetomidine of Different Concentrations Combined with Butorphanol for Post-Caesarean Section Analgesia: A Randomized Controlled Trial

Purpose: The present study aimed to determine the effectiveness of intravenous dexmedetomidine of different concentrations and to evaluate its maternal and neonatal safety when combined with butorphanol in parturients undergoing cesarean section.

Patients and methods: A total of 114 parturients between 24 and 43 years of age, with singleton pregnancy who underwent elective cesarean section under epidural anesthesia, were randomly allocated to four groups: group C received 0.9% sodium chloride after delivery, followed by butorphanol (3 μg·kg^-1·h^-1); patients in groups D1, D2, and D3 received 0.5 μg·kg^-1·h^-1 dexmedetomidine after delivery, followed by butorphanol (3 μg·kg^-1·h^-1) combined with dexmedetomidine 0.03, 0.05, and 0.08 μg·kg^-1·h^-1, respectively. The primary outcome was the visual analogue scale (VAS) score at 6 h after delivery when patients were at rest. Secondary outcome measures included VAS after delivery when patients were on movement and uterine cramping, Ramsay sedation scale (RSS), relative infant dose (RID) of dexmedetomidine, satisfaction with analgesia after surgery and symptoms of CNS depression in neonates.

Results: There were no significant differences in patient characteristics among the groups (P > 0.05). The VAS at all timepoints after delivery in groups D2 and D3 were significantly lower than in groups C and D1 (P < 0.001). RSS scores were clearly higher in group D3 than in the other three groups at 6 h and 12 h (P < 0.0001). RID in groups D1, D2, and D3 was 0.171%, 0.197%, and 0.370%, respectively. Compared with group D1, RID was higher in group D3 (P = 0.0079). Degree of satisfaction with analgesia was higher in groups D2 and D3 (P < 0.005).

Conclusion: Continuous intravenous infusion of 0.05 μg·kg^-1·h^-1 dexmedetomidine combined with 3 μg·kg^-1·h^-1 butorphanol could be safely applied in healthy parturients with satisfactory analgesia after cesarean section without changes in sedation.