title: Fetal lactic acidosis with epidural anesthesia.
abstract: Three hundred thirty-six consecutive cesarean deliveries performed under epidural anesthesia were reviewed. Twenty per cent of mothers suffered at least a 20% fall in blood pressure following administration of epidural anesthesia. An additional 24% required ephedrine, a vasopressor with predominantly beta activity, when other corrective measures failed. Thus, 44% of these patients suffered significant hypotension. Forty-one percent of all elective repeat cesarean sections were treated wih ephedrine because of maternal hypotension. Fifty-one patients delivered by scheduled repeat cesarean section were divided into ephedrine-treated and untreated groups. There were no differences in Apgar scores among infants of both groups. Fetal acidosis was proportional to the severity of hypotension and the ephedrine dose. The metabolic abnormalities were most pronounced when severe hypotension, requiring over 15 mg of ephedrine, was present. Following restoration of blood pressure with conventional measures and ephedrine therapy, lactic acidosis persisted until delivery, whereas PO2 and PCO2 reverted toward normal values. The hypoperfusion of the intervillous space was the most likely cause of the observed significant umbilical venous and arterial lactic acidosis. Maternal hypotension remains a significant problem complicating conduction anesthesia.
mesh_terms: D000138:Acidosis / Q000209:etiology*; D000767:Anesthesia, Epidural / Q000009:adverse effects*; D001784:Blood Gas Analysis; D002585:Cesarean Section; D004809:Ephedrine / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007022:Hypotension / Q000150:complications / Q000209:etiology* / Q000517:prevention & control; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000209:etiology*; D007773:Lactates / Q000097:blood*; D008297:Male; D007744:Obstetric Labor Complications / Q000209:etiology*; D011247:Pregnancy
chemical_list: D007773:Lactates; D004809:Ephedrine