Spinal and epidural sufentanil and fentanyl in early labour.

In terms of a reduction of VAS score at 20 minutes, epidural sufentanil or fentanyl provide 63% and 60% of the analgesic effect of the corresponding spinal analgesia. Epidural sufentanil or fentanyl could be used in situations in which spinal/CSE administration is not possible or desired.