The loading dose for continuous infusion epidural analgesia. A technique to reduce the incidence of hypotension

The effects of 0.08% and 0.5% bupivacaine, given in equal volumes as the loading dose prior to continuous infusion epidural analgesia, were compared. The incidence of hypotension, as well as the height of sensory blockade, was markedly lowered by reducing the loading dose of bupivacaine. However, the efficacy of the epidural analgesia was maintained by using the same volume for the loading dose. The mean onset of analgesia was delayed from 9.1 to 13.6 minutes. There were fewer calls for intervention consequent upon the reduction in adverse effects. The use of 8 ml 0.08% bupivacaine for the loading dose or for subsequent top-ups is recommended. The concept of a liquid sleeve of local anaesthetic in the epidural space is further supported.