A comparison of three doses of sufentanil in combination with bupivacaine-adrenaline in continuous epidural analgesia during labour.

Background: Sufentanil is now frequently added to local anaesthetic in labour epidural analgesia. However, this opioid has some side effects such as pruritus, and in higher doses could harm the neonate. The purpose of this study was to compare three doses of sufentanil combined with low-dose bupivacaine, to determine the lowest appropriate dose.

Method: In a prospective, randomized, double-blind study, 243 parturients were randomized, to receive A--0.5 microg/ml, or B--0.75 microg/ml or C--1 microg/ml sufentanil, in addition to bupivacaine 0.625 mg/ml+adrenaline 1.25 microg/ml. All were given an 8 ml bolus of the study solution, followed by continuous infusion at 6 ml/h. The analgetic effect was scored on a visual analogue scale (VAS). Onset quality was measured as VAS after 20 min, the total effect as VAS maximum during the first stage of labour. Overall maternal satisfaction was recorded within two hours post partum. Side effects were noted.

Results: There were no differences between groups in VAS assessments after 20 min or in maximum registered VAS. In group A, 83% had VAS 0-4 after 20 min, in group B 77% and in group C 71%. Maximum VAS during the first stage was 0-4 for 60% of group A, 68% of group B and 61% of group C. Maternal satisfaction was also the same in the three groups. In group A, 70% reported excellent effect and 22% good effect. The corresponding figures in group B were 68% and 24% respectively, and in group C 62% and 24% respectively. Group A received a mean total dose of 21 microg sufentanil, group B 30 microg and group C 44 microg. Pruritus occurred in 51% of group A, 53% of group B and 65% of group C.

Conclusion: We found no difference in the analgesic effect between three different concentrations of sufentanil. We conclude that the lowest dose may be used. This should decrease the risk of adverse effects on mother and child.