Clonidine versus sufentanil as an adjuvant to ropivacaine in patient-controlled epidural labour analgesia: A randomised double-blind trial.

BACKGROUND

Adjuvants to local anaesthetics for epidural labour analgesia are useful if they reduce side-effects or personnel requirements. Epidural clonidine improves analgesia and provides a significant local anaesthetic-sparing effect.

OBJECTIVE

To compare the number of rescue doses administered by the anaesthesiologist when clonidine or sufentanil is added to epidural ropivacaine.

DESIGN

A randomised double-blind trial.

SETTING

Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium, from June 2009 to June 2010.

PATIENTS: One hundred and ninety-five women in labour.

INTERVENTION: Epidural analgesia initiated with 10 ml ropivacaine 0.1%, women randomised to receive patient-controlled epidural analgesia (5 ml demand bolus, 15 min lockout) with ropivacaine 0.1% and sufentanil 0.25 μg ml⁻¹ (RS group; n = 65), or ropivacaine 0.1% and clonidine 1.5 μg ml⁻¹ (RC1.5 group; n = 65) or ropivacaine 0.1% and clonidine 3 μg ml⁻¹ (RC3 group; n = 65). Rescue analgesia was available as needed – 10 ml ropivacaine 0.1% (numerical rating scale <6/10) or ropivacaine 0.2% (numerical rating scale ≥6/10).

MAIN OUTCOME: Comparison of the total number of rescue doses.

RESULTS

The total number of rescue doses was similar among the groups [median (interquartile range): 1 (0 to 1) in the RC1.5 group, 1 (1 to 2) in the RC3 group and 2 (1 to 2) in the RS group; overall P = 0.056]. However, fewer patients in both the RC1.5 and RC3 groups needed two or more rescue doses (25 and 29% versus 52% in the RS group, P = 0.01). The rate of instrumental delivery was higher in both clonidine groups (13 and 12% versus 0%, P = 0.03). Nausea was significantly less frequent in both the clonidine groups. Satisfaction scores, total ropivacaine consumption, maternal sedation, and hypotension and neonatal outcomes were similar among the groups.

CONCLUSION

Compared with sufentanil 0.25 μg ml⁻¹, addition of clonidine (1.5 to 3 μg ml⁻¹) to patient-controlled epidural analgesia with ropivacaine 0.1% provided similar labour analgesia and a similar need for anaesthesiologist-administered rescue doses. Clonidine 3 μg ml⁻¹ did not offer any advantage over clonidine 1.5 μg ml⁻¹. The instrumentation rate was higher in both the clonidine groups.