Selective lumbar epidural block in labour. A clinical analysis.

Segmental epidural analgesia (T10-T12) was performed in 418 parturients, using a 4-6 ml dose of 0.5% bupivacaine, with or without adrenaline. Seventy per cent of parturients were primiparas and 30% had histories, or signs, of possible uteroplacental insufficiency. Our aim was to relieve pain during the long passive opening phase, so that mothers would be rested and active at the beginning of the second phase, but also to avoid abolishing the bearing-down reflex, the absence of which causes an increased frequency of instrumental delivery. The analgesia during the opening phase was of good quality in 89% of primiparas, and 84% of multiparas. The onset of analgesia was rapid (3-5 min) and the duration was on average 2 1/2 h. The incidence of foetal heart rate changes, during the 30 min after epidural, was 5%. The second phase was less than 30 min in about 90% of cases. About 90% of parturients delivered spontaneously, and the frequency of instrument delivery was only 7.4%. Caesarean section was required in 3.7%. Slight, but rapidly correctable, hypotension occurred in 16.5%, and in two cases the hypotension led to more serious complications. This stresses the importance of the availability and competence of both the anaesthetic and obstetric teams. There were no maternal or neonatal mortalities, and the Apgar scores compared well with the figures for the normal material in our obstetric unit.