Ropivacaine 0.2% versus bupivacaine 0.1% with fentanyl: a double blind comparison for analgesia during labour

We have performed a randomized, double-blind comparison of two epidural drug regimens for analgesia in labour. In the bupivacaine group (BUPIV), 101 healthy parturients received 0.1% bupivacaine with fentanyl 2 microg ml(-1). In the ropivacaine group (ROPIV), 102 women received 0.2% ropivacaine. Both groups received an initial loading dose of 15 ml, a continuous infusion of 8 ml h(-1), and top-ups of 10 ml. Breakthrough pain not responding to a routine top-up was treated with an 'escape' top-up of 10 ml 0.25% bupivacaine. The two groups were compared for complete analgesia at 30 min, routine and 'escape' top-up requirements, midwife assessment of analgesic efficacy, delivery mode, patient visual analogue scores (VAS) for first and second stage analgesia, overall satisfaction, and patient assessment of motor blockade. Patients receiving ropivacaine received fewer routine top-ups (median 1.0 vs. 2.0, P=0.001) and fewer escape top-ups (9.8% vs. 21.8%, P=0.02). The ropivacaine group was more likely to be pain free in the first stage (51% vs. 33.7%, P=0.01). There were no significant differences in patients' assessment of motor block or mode of delivery between the groups. Pain relief and satisfaction scores from midwives and patients were consistently better in the ropivacaine group, but did not reach statistical significance.