Bupivacaine compared with etidocaine for vaginal delivery

A comparison of 0.5 percent etidocaine with 0.25 and 0.5 percent bupivacaine, using continuous (intermittent) caudal block in 60 vaginal deliveries, showed the latter two solutions to be the agents of choice. All solutions contained a final concentration of 1:2000,000 epihephrine. In 40 parturients given either 0.25 or 0.5 percent bupivacaine, all had pain relief after the initial dose, while 5 of 20 given etidocaine required a refill dose within 30 to 50 minutes for complete pain relief. The duration of action of the initial dose with both concentrations of bupivacaine was longer than that of etidocaine. The degree of motor blockade with 0.5 percent etidocaine was greater than with 0.5 percent bupivacaine, and with 0.5 percent concentrations of either etidocaine or bupivacaine was greater than with 0.25 percent bupivacaine. The duration of motor blockade of 0.5 percent etidocaine and bupivacaine was comparable. The duration of motor blockade of the 0.25 percent concentration of bupivacaine was shorter than with the 0.5 percent concentration of both etidocaine and bupivacaine; and with both bupivacaine concentrations the duration of sensory anesthesia in the extremities was longer than motor blockade; with etidocaine, the opposite occurred.