The quantitative effect of lumbar analgesia on uterine work output.

The effect of lumbar epidural analgesia on uterine work output was studied in 36 women during labour. During the first 10 minutes after administration of the local anaesthetic agents there was a 46% loss of uterine activity. In 72% of patients uterine activity returned to normal within 30 minutes. Seventeen per cent of patients required additional oxytocic stimulation.