Intrathecal ropivacaine or bupivacaine with fentanyl for labour

Combined spinal-epidural (CSE) is widely used to provide pain relief in labour while minimizing motor blockade. Aiming to further reduce associated motor weakness, we compared ropivacaine 2.5 mg in the intrathecal injection with a standard bupivacaine CSE in a double-blind study. Forty women were randomized to receive either bupivacaine 2.5 mg or ropivacaine 2.5 mg intrathecally, both with fentanyl 0.025 mg. There were no significant differences between the groups regarding the onset, duration or quality of analgesia or the level of sensory block attained. Forty per cent of the women (8/20) receiving bupivacaine developed detectable motor block compared with only 5% (1/20) in the ropivacaine group (P<0.05). Vibration sense was impaired in one woman in each group. Adverse effects did not differ between groups. We conclude that intrathecal ropivacaine 2.5 mg in combination with fentanyl 0.025 mg as part of a CSE technique provides rapid and safe analgesia for labour as effective as that achieved with bupivacaine 2.5 mg and with significantly less motor block.