Double-blind comparison of ropivacaine 7.5 mg ml(-1) with bupivacaine 5 mg ml(-1) for sciatic nerve block

Two groups of 12 patients had a sciatic nerve block performedwith 20 ml of either ropivacaine 7.5 mg ml^–1 or bupivacaine5 mg ml^–1. There was no statistically significant differencein the mean time to onset of complete anaesthesia of the footor to first request for post-operative analgesia. The qualityof the block was the same in each group. Although there wasno statistically significant difference in the mean time topeak plasma concentrations the mean peak concentration of ropivacainewas significantly higher than that of bupivacaine. There wereno signs of systemic local anaesthetic toxicity in any patientin either group. Br J Anaesth 2001; 86: 674–7