The frequency of fetal bradycardia during selective epidural anaesthesia.

The frequency of marked fetal bradycardia (FB) during selective lumbar epidural anaesthesia with 0.25% or 0.5% bupivacaine (Marcain, Bofors) without adrenaline in doses of 5 ml to 8 ml is reported. 35 patients were monitored by means of the Hewlett-Packard Cardiotocograph with Hon's spiral scalp electrode and a transcervical catheter connected to a Hewlett-Packard (1280 B/C) physiological pressure transducer. Only patients with a normal cardiotocogram (CTG) before anaesthesia are included. During the second stage pathological fetal heart rate (FHR) patterns and technical artefacts are common, therefore the CTGs recorded in this period were not considered. In the 35 patients the total time of intrauterine monitoring was 119 hours. During this period 125 doses of 0.25% and 23 doses of 0.5% bupivacaine were given. In 33 parturients the FHR changes observed were insignificant. In one case a period of marked FB was seen. One parturient developed acute hypotension with a synchronous FB while lying in the supine position. It is concluded that continuous lumbar epidural anaesthesia with bupivacaine without adrenaline does not precipitate FB during the first stage when care is taken to avoid maternal hypotension.