Pudendal block in vaginal deliveries. Mepivacaine with and without epinephrine.

Pudendal block with 20 ml 1% mepivacaine with and without epinephrine was performed in 151 patients during the second stage of labor. No differences in efficacy of the block or in Apgar scores between the two groups were found. The maternal mepivacaine concentration was higher in the plain group than in the epinephrine group (p less than 0.01), but toxic levels were never reached. In the infants, no difference in mepivacaine concentration was found between the groups (p greater than 0.05, type II error 9%) and toxic levels were not reached. The time elapsed from the pudendal block until delivery was prolonged when epinephrine was added (p less than 0.02). We found no effect on blood pressure in either of the groups, with or without oxytocin and/or methergin. Twenty ml 1% mepivacaine (plain) is a safe choice for pudendal block without the possible disadvantages of adding epinephrine.