Extradural analgesia in labour: complications of three techniques of administration.

We have studied the complications associated with three techniques used to maintain extradural analgesia in labour: midwife top-up doses of 0.25% bupivacaine 10 ml, continuous infusion of 0.125% bupivacaine 10 ml h-1 and patient-controlled extradural analgesia (PCEA) with self-administered 3-ml bolus doses of 0.25% bupivacaine. A significantly higher intervention rate by an anaesthetist was required in the continuous infusion group. There was no difference in the mode of delivery between the three groups, although some women in the continuous infusion group had significantly denser motor block. There was a similar incidence of rectal pressure, unilateral block and missed segments in the three groups. Uneventful hypotension occurred in three women; two receiving PCEA and one receiving continuous infusion. Ten women experienced sensory blocks extending above T7 with no ill effects; seven receiving PCEA and three continuous infusion.