Use of chloroprocaine for obstetric analgesia.

The effects of low concentration chloroprocaine in continuous lumbar epidural analgesia during labor and delivery, were evaluated in 21 subjects. The final analysis was made on 18 parturientis, 9 receiving 1.5% (group A) and 9 1.33% chloroprocaine (group B), in a standard dose of 7-8 ml (first test dose 2-3 ml), and of 12 ml for the second stage of labor. Onset of analgesia occurred 7.4 +/- 1.2 (mean +/- S.D.) (group A) and 9.6 +/- 1.8 min. (group B) after injection (difference significant). Mean interval between first and second doses was 50.5 +/- 6.3 (group A) and 47.5 +/- 10.8 (group B) min. (difference N.S.). In group A 6 patients and in group B only 1 patient had a temporarily decrease in bloodpressure below 100 mm Hg. During routine monitoring, pathological F.H.R. patterns were recorded in 2 cases. Apgar scores and acid-base parameters were within normal limits in both groups (difference N.S.).