The effect of adrenaline on the efficacy of extradural block and plasma bupivacaine concentrations was investigated in women undergoing elective (n = 40) and emergency (n = 40) Caesarean section. Patients were randomly allocated within these two groups to receive 0.5% bupivacaine 20 ml either plain or with adrenaline 1 in 200,000, as a single fractionated extradural injection. The elective plai...