A randomized double-blind study evaluated the analgesic efficacy and influence of maintaining a continuous epidural infusion of 0.75% lidocaine during the second stage of labor in nulliparous women. When the cervix was 8 cm or more dilated, unidentified study solution was substituted for the known 0.75% lidocaine solution and continued until delivery. The study solution for 26 patients was 0.75% lidocaine; 27 subjects received saline. During the first stage of labor, 88% of women in the lidocaine group and 81% of women in the saline group had analgesia of excellent or good quality, a nonsignificant difference. During the second stage, there was a tendency (not statistically significant) toward improved analgesia quality in the lidocaine patients, but there was no significant difference in the frequency of perineal anesthesia (23% lidocaine, 7% saline). There was no difference between the groups in the duration of the second stage of labor (73 +/- 63 versus 76 +/- 48 minutes). Operative delivery frequency was similar (31 and 37%), as were umbilical cord blood acid-base values. It is concluded that maintenance of the continuous epidural infusion of 0.75% lidocaine did not prolong the second stage of labor, but it also did not significantly differ from saline in quality of second stage analgesia or frequency of perineal anesthesia.