Extradural anaesthesia for caesarean section: a double-blind comparison of 0.5% ropivacaine with 0.5% bupivacaine

Seventy-three parturients for elective Caesarean section were allocated randomly to receive extradural block with 20 ml of either 0.5% ropivacaine or 0.5% bupivacaine. If the block did not reach T6 within 30 min, another 5 ml of solution was given. If needed, a further 5 ml was given 45 min after the main dose. The mean total dose of bupivacaine was 23.1 ml (n = 35) and of ropivacaine 23.7 ml (n = 37). There was no significant difference between the groups in the profile of sensory block produced. There was no significant difference in the time of onset, or intensity of motor block between the groups but the duration of motor block was significantly shorter in the ropivacaine group. There was no significant difference in neonatal outcome, as assessed by Apgar score, umbilical cord blood-gas tensions at delivery or the neurological and adaptive capacity score 2 and 24 h after delivery.