A single dose epidural technique for caesarean section. A comparison between 0.5% bupivacaine plain and 0.5% bupivacaine with adrenaline.

An epidural technique based on a fractionated injection through a Tuohy needle of 20 ml over 10 minutes, was investigated in 40 mothers who underwent elective caesarean section. Mothers were randomized to receive either 0.5% bupivacaine plain or 0.5% bupivacaine with adrenaline 1:200,000. After a 2-ml test dose, the remaining 18 ml was injected over 5 minutes. The use of adrenaline did not significantly alter the onset or duration, but improved the efficacy of the epidural block. Mean time to onset of adequate surgical anaesthesia was 20 minutes. Only 10 patients required more than the initial 100 mg of bupivacaine. Epidural anaesthesia was supplemented in eight patients with nitrous oxide and/or intravenous opioids.