A double-blind comparison of 0.25% ropivacaine and 0.25% bupivacaine for extradural analgesia in labour

Abstract

Ropivacaine is a new aminoamide local anaesthetic. Compared with bupivacaine, ropivacaine possesses a higher threshold for systemic toxicity and a high selectivity for sensory fibres. We have compared prospectively these two agents in a concentration of 0.25% for extradural analgesia in labour. A total of 104 parturients requesting extradural analgesia were randomized to receive either ropivacaine or bupivacaine. The women in the bupivacaine group required more top-up doses to maintain analgesia (median 3.0 vs 2.0) (P < 0.05). The onset of sensory block, quality of analgesia, ultimate level of maximum sensory block and maternal satisfaction were similar in both groups. The incidence, intensity and duration of motor block were slightly but not significantly less in the ropivacaine group. The ropivacaine group had a higher incidence of spontaneous vaginal delivery (70.59% vs 52.00%). There was no significant difference in neonatal outcome as assessed by Apgar scores, umbilical acid-base status and neurological and adaptive capacity score at 2 and 24 h after delivery. We conclude that ropivacaine and bupivacaine in a concentration of 0.25% produced comparable analgesia for pain relief of labour with no detectable adverse effect on the neonate.

Comparison of ropivacaine 0.1%-fentanyl and bupivacaine 0.125% — fentanyl infusions for epidural labour analgesia

“…However, in this study, intermittent injection rather than infusions were used for analgesia and the bupivacaine group needed more top-up injections than did the ropivacaine group. Both these studies showed 13,14 that ropivacaine, despite its lower potency, provided similar degree of analgesia as bupivacaine at comparable concentration.…”

Epidural ropivacaine hydrochloride during labour: protein binding, placental transfer and neonatal outcome

“…An aliquot of 100 ml of sample was added to Iprindol 1 mg.l 21 (internal standard), 0.1 ml ammonium hydroxide and 50 ml N-butyl acetate into a Dreyer tube. The range of standards was 0.1± 2.0 mg.ml 21 for total ropivacaine and 0.02± 0.2 mg.ml 21 for unbound ropivacaine. The coefficients of variation were 6.5% (within assay) at 0.2 mg.ml 21 and 2.3% at 2.0 mg.ml 21 (within assay).…”

A comparison of 1% ropivacaine with a mixture of 0.75% bupivacaine and 2% lignocaine for peribulbar anaesthesia

“…Ropivacaine may therefore be expected to be less potent. However, clinical dose-finding studies have suggested a similar anaesthetic potency to bupivacaine, although with slightly different pharmacodynamic effects [7][8][9]. Higher concentrations of ropivacaine (0.5-1.0%), when given into the epidural space, have been found to provide equal sensory and motor blockade to similar concentrations of bupivacaine, but with a motor blockade of shorter duration [10][11][12][13].…”