A controlled trial of extradural fentanyl in labour.

In a double-blind trial carried out on patients in the first stage of labour, either fentanyl 80 micrograms (n = 35) or physiological saline (n = 33) was added to the test dose of bupivacaine and administered extradurally. Thereafter analgesia was maintained as necessary with 0.5% bupivacaine alone. Supplementary bupivacaine (a further dose within 1 h) was required to produce satisfactory analgesia in eight patients in the fentanyl group and in 26 patients in the control group. Analgesia was more rapid in onset and more complete in the fentanyl group, and the duration from first dose to first top-up was 2.36 h, compared with 1.66 h (supplements notwithstanding) in the control group. No serious side-effects were encountered in either group, although eight patients in the fentanyl group experienced mild itching, compared with one in the control group.