Epidural fentanyl in labour

Abstract
In a randomised double‐blind trial in the first stage of labour, 20 patients given fentanyl 80 μg in the epidural test dose of bupivacaine, were compared with 20 patients receiving an intravenous infusion designed to produce comparable plasma fentanyl concentrations, at the same time as their epidural test dose. Despite slightly higher plasma fentanyl concentrations in the intravenous, fentanyl group, epidura1, fentanyl produced analgesia which was more complete, more rapid in onset and slightly longer lasting. Supplementary doses of bupivacaine were needed to produce analgesia in 75% of the inlravenous and 30% of the epidural fentanyl group. It is clear that epidural, fentanyl produces satisfactory pain relief when added to the epidural test dose, but that the presence of fentanyl in the systemic circulation makes a negligible contribution to analgesia.