Evaluation of etidocaine in extradural block.

Etidocaine has been evaluated in extradural block with regard to its absorption, toxicity and clinical effectiveness, which have been compared with those of bupivacaine. Etidocaine is associated with lower plasma concentrations than bupivacaine and its absorption is decreased by the addition of adrenaline 1:200,000 to a greater extent than is the case with bupivacaine. Etidocaine causes motor paralysis more frequently than does bupivacaine, especially if adrenaline is added. The duration of action of the two drugs is similar when comparing etidocaine 1% and bupivacaine 0.5%. Bupivacaine 0.75%, however, acts for a significantly longer time than etidocaine 1%. The drug is a useful addition to the range of local anaesthetics, especially with regard to the degree of motor blockade it can achieve during surgical procedures.