Abstract
A total of 22 full term women with uncomplicated pregnancies were given continuous epidural analgesia using a 0.4 per cent lidocaine drip solution either without (series I), or with freshly added epi-nephrine (series II). In both series a transient decrease in uterine activity occurred immediately after the induction of analgesia with 50 mg lidocaine. The spontaneous recovery time was 20-30 minutes. In series II a more marked transitory depression of the uterine activity was recorded following a dose of 50 mg lidocaine with epinephrine, given immediately before commencing the drip infusion. Apart from these initial effects, caused by single doses, the normal progress of the first stage of labour was not significantly altered by the drip infusion. As in a previously studied series of patients, given intermittent epidural anaesthesia, a tendency to prolongation of the second stage was observed. Pathological foetal heart rate patterns were rare and never present as a consequence of maternal hypotension. Serial determination of foetal and maternal pH, Pco2, and BDecf could not demonstrate any adverse effect of the block on these variables. The influence of the duration of the second stage on foetal pH and base deficit levels were less pronounced than in a “normal” control series, suggesting better intrauterine foetal condition in the anaesthetized cases.