Effect of dexmedetomidine combined with sufentanil for post-caesarean section intravenous analgesia: a randomised, placebo-controlled study.

ABSTRACT

BACKGROUND: Few studies have investigated the use of dexmedetomidine in obstetric anaesthesia. OBJECTIVE: To evaluate the effect of dexmedetomidine combined with sufentanil for patient-controlled analgesia (PCA) after caesarean section under spinal anaesthesia. DESIGN: An interventional, randomised, double-blinded, placebo-controlled clinical study. SETTING: Department of Anaesthesiology, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China. PATIENTS One hundred and twenty parturients (American Society of Anesthesiologists class 1 or 2) scheduled for elective caesarean delivery under spinal anaesthesia randomly allocated into three groups (n = 40 each). INTERVENTIONS: Group 1 physiological saline bolus after delivery and sufentanil PCA, Group 2 dexmedetomidine bolus (0.5 µg kg) after delivery and sufentanil PCA, Group 3 dexmedetomidine bolus (0.5 µg kg) after delivery and sufentanil with dexmedetomidine PCA (background infusion of 0.045 µg kg h with a bolus of 0.07 µg kg). MAIN OUTCOME MEASURES: The total consumption of sufentanil. Pain scores at rest evaluated with a visual analogue scale (VAS) and Ramsay sedation score (RSS) were recorded at the 4, 8 and 24 h after surgery. The patients' pain threshold (PTh) and pain tolerance threshold (PTTh) were measured before surgery and 1 h after initial study drug administration. Satisfaction scores were collected 24 h after surgery. RESULTS: Sufentanil consumption in group 3 was 43.9 ±â€Š19.2 µg, significantly lower than in group 1 (54.5 ±â€Š23.9 µg) and group 2 (56.3 ±â€Š20.6 µg) (P < 0.05). Compared with group 3, VAS was increased at 4, 8 and 24 h after surgery in groups 1 and 2 (P < 0.05); there was no difference between groups 1 and 2. PTh and PTTh were significantly increased 1 h after drug administration in groups 2 (1.59 ±â€Š0.45, 2.57 ±â€Š0.46 mA) and 3 (1.74 ±â€Š0.37, 2.56 ±â€Š0.48 mA) compared with group 1 (1.49 ±â€Š0.49, 2.42 ±â€Š0.62 mA) (P < 0.05). CONCLUSION: The combination of sufentanil and dexmedetomidine for PCA after caesarean section can reduce sufentanil consumption and improve parturients' satisfaction compared with sufentanil PCA alone. TRIAL REGISTRATION ChiCTR-TRC-11001442.