Cardiovascular changes in labour associated with extradural analgesia using bupivacaine.

Cardiovascular changes were monitored continuously in 13 women during stimulated labour conducted under extradural analgesia with bupivacaine. Three solutions of bupivacaine (0.5% plain, 0.25% with adrenaline and 0.5% with adrenaline) were administered in a random fashion. The results show that the plain solution of bupivacaine was associated with a decrease in central venous pressure and an increase in maternal heart rate which approached statistical significance 40-45 min after administration. These changes did not occur when solutions containing adrenaline were used. The small number of patients and the random administration of the bupivacaine solutions make it difficult to establish the exact significance of the cardiovascular changes observed and a further within-patient study is required.