Comparison of plain and alkalinized local anaesthetic mixtures of lignocaine and bupivacaine for elective extradural caesarean section.

We have examined a local anaesthetic mixture of 0.5% bupivacaine 10 ml and 2% lignocaine 10 ml with adrenaline 1 in 200,000, to which 8.4% sodium bicarbonate 2 ml was added, for extradural Caesarean section. The alkalinized mixture of local anaesthetics produced a block of more rapid onset and density than a mixture of bupivacaine and lignocaine alone (P less than 0.001).