Continuous extradural infusion of 0.125% bupivacaine for pain relief after lower abdominal surgery.

Twenty women, undergoing lower abdominal surgery, were allocated randomly to receive a continuous extradural infusion of either 0.125% bupivacaine or placebo at a rate of 15 ml h-1. All had received an intra-operative extradural block. Pain scores were recorded at 30, 60, 90, 120, 150, 180, 240 and 360 min after surgery. From 150 min onwards there was a significant benefit for those receiving the active drug. Six of nine patients in this group had adequate analgesia over the 6-h study period, while all patients in the placebo group required further pain relief.