Effect of sufentanil on minimum local analgesic concentrations of epidural bupivacaine, ropivacaine and levobupivacaine in nullipara in early labour

Buyse, I.; Stockman, W.; Columb, M.; Vandermeersch, E.; Van de Velde, M.

doi:10.1016/j.ijoa.2006.07.008

« Previous Next »International Journal of Obstetric Anesthesia
Volume 16, Issue 1 , Pages 22-28, January 2007

Effect of sufentanil on minimum local analgesic concentrations of epidural bupivacaine, ropivacaine and levobupivacaine in nullipara in early labour

Departments of Anaesthesiology, Heilig Hart Hospital, Roeselare, and University Hospital Gasthuisberg, Leuven, Belgium and South Manchester University Hospital, Wythenshawe, UK

Accepted 1 July 2006. published online 26 November 2006.

I. Buyse, Resident, Department of Anaesthesiology, University Hospital Gasthuisberg, Leuven, Belgium, W. Stockman, Staff Member, Department of Anaesthesiology, H. Hart Hospital, Roeselare, Belgium, M. Columb, Consultant in Anaesthesia and Intensive Care Medicine, South Manchester University Hospital, Wythenshawe, UK, E. Vandermeersch, Professor and Chairman, Department of Anaesthesiology, University Hospital Gasthuisberg, Leuven, Belgium, M. Van de Velde, Associate Professor, Consultant Anaesthetist, Department of Anaesthesiology, University Hospital Gasthuisberg, Leuven, Belgium.

Background

The aim was to assess the effect of epidural sufentanil on relative analgesic potencies of epidural bupivacaine, ropivacaine and levobupivacaine by determining the minimum local analgesic concentrations during labour.

Methods

In a randomised, double-blind study, 171 parturients were allocated to one of six groups receiving a 10-mL bolus of bupivacaine, ropivacaine or levobupivacaine alone or with sufentanil 0.75 μg/mL. The concentration of local anaesthetic was determined by the response of the previous parturient using up-down sequential allocation starting at a concentration of 0.13% wt/vol with a testing interval of 0.01%. Effective analgesia was defined as a visual analogue pain score ⩽15/100 mm within 30 min and lasting for 30 min. Median effective concentrations were estimated and two-sided P<0.05 was significant.

Results

Local anaesthetic concentration, use of sufentanil and local anaesthetic drug were independent significant predictors of effective and ineffective analgesia. Bupivacaine was significantly more potent than levobupivacaine and ropivacaine. The relative potency ratios without sufentanil of 0.77:0.83:1.00 were reduced to 0.36:0.38:1.00 by the addition of sufentanil. The major factor influencing local anaesthetic requirements was the addition of sufentanil, which reduced overall requirements by a factor of 4.2 (95% CI 3.6–4.8); this effect was proportionately more enhanced for bupivacaine.

Conclusions

Local anaesthetic requirements for bupivacaine, levobupivacaine and ropivacaine follow an analgesic potency hierarchy. Any potency differences are small when compared to the effect of sufentanil, which resulted in a four-fold reduction in local anaesthetic requirements. Sufentanil may also enhance the potency differences between bupivacaine and the two S-enantiomer agents.

Keywords: Labour, Analgesia, Epidural, Ropivacaine, Bupivacaine, Levobupivacaine, Sufentanil, Minimal local analgesic concentration