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

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 ± 19.2 μg, significantly lower than in group 1 (54.5 ± 23.9 μg) and group 2 (56.3 ± 20.6 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 ± 0.45, 2.57 ± 0.46 mA) and 3 (1.74 ± 0.37, 2.56 ± 0.48 mA) compared with group 1 (1.49 ± 0.49, 2.42 ± 0.62 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.