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 labo ur epidural analgesia. However, this opioid has some side effects such as p ruritus, and in higher doses could harm the neonate. The purpose of this st udy was to compare three doses of sufentanil combined with low-dose bupivac aine, to determine the lowest appropriate dose. Method: In a prospective, randomized, double-blind study, 243 parturients w ere randomized, to receive A - 0.5 mu g/ml, or B - 0.75 mu g/ml or C - 1 mu g/ml sufentanil, in addition to bupivacaine 0.625 mg/ml+adrenaline 1.25 mu g/ml. All were given an 8 mi bolus of the study solution, followed by cont inuous infusion at 6 ml/h. The analgetic effect was scored on a visual anal ogue 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 s atisfaction was recorded within two hours post partum. Side effects were no ted. 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 m in, in group B 77% and in group C 71%. Maximum VAS during the first stage w as 0-4 for 60% of group A, 68% of group B and 61% of group C. Maternal sati sfaction was also the same in the three groups. In group A, 70% reported ex cellent effect and 22% good effect. The corresponding figures in group B we re 68% and 24% respectively and in group C 62% and 24% respectively. Group A received a mean total dose of 21 mu g sufentanil, group B 30 mu g and gro up C 44 mu g. Pruritis occurred in 51% of group A, 53% of group B and 65% o f group C. Conclusion: We found no difference in the analgesic effect between three di fferent concentrations of sufentanil. We conclude that the lowest dose may be used. This should decrease the risk of adverse effects on mother and chi ld.