Which local anesthetic is best suited for paracervical blocks?

In a prospective, randomized study the duration and effectiveness of four different regimens of PCB were studied: Bupivacaine both with and without adrenaline, and chloroprocaine with and without adrenaline. The pain relief was immediate and almost complete in most patients in all four treatment groups. The duration of the effect of bupivacaine was the same whether adrenaline was added or not. The labors were significantly prolonged with adrenaline, however. The duration of the effect of chloroprocaine was substantially shorter than bupivacaine, but with this short-lasting anesthetic the duration was prolonged by the addition of adrenaline. It is concluded that bupivacaine without the addition of adrenaline is the drug of choice for PCB.