title: Fetal effects of prophylactic ephedrine and maternal hypotension during regional anesthesia for cesarean section.
abstract: The purpose of this study was to evaluate the effects of a prophylactic intravenous bolus of ephedrine on the incidence and severity of maternal hypotension and on neonatal outcome. Term healthy parturients (n = 122) scheduled for elective repeat cesarean section under regional anesthesia were studied. Ninety-two women received 10 mg ephedrine as a prophylactic intravenous bolus prior to intrathecal epidural local anesthesia. Thirty parturients who served as controls did not receive prophylactic ephedrine. Maternal blood pressures, Apgar scores, and umbilical cord blood acid-base status were evaluated. Sixty-three of 92 women (69%) who received intravenous prophylactic ephedrine prior to regional anesthesia developed hypotension compared to 21 (70%) controls. The mean (+/- SD) lowest systolic blood pressure was similar in both groups (95.6 +/- 12.9 vs. 96 +/- 8.9 mmHg; P = 0.86). The mean (+/-SD) fetal pH was significantly lower with prophylactic ephedrine than controls (7.24 +/- 0.07 vs. 7.28 +/- 0.05; P = 0.001). The frequency of umbilical artery blood pH < 7.20 was 10.6% for the ephedrine group vs. 3.2% for controls (P = 0.024). Among newborns of hypotensive mothers, the frequency of umbilical artery blood pH < 7.20 was 30.2% and 4.6% for the ephedrine and control groups, respectively (P = 0.018). Intravenous prophylaxis with ephedrine did not significantly decrease the frequency of hypotension in women receiving regional anesthesia and resulted in a greater proportion of umbilical artery blood pH values < 7.20.
authors.affiliation: Department of Anesthesiology, University of Texas Southwestern Medical Center, Dallas 75235-9032, USA.
authors.forename: V E
authors.initials: VE
authors.lastname: Shearer
authors.forename: S M
authors.initials: SM
authors.lastname: Ramin
authors.forename: D H
authors.initials: DH
authors.lastname: Wallace
authors.forename: J S
authors.initials: JS
authors.lastname: Dax
authors.forename: L C
authors.initials: LC
authors.lastname: Gilstrap
mesh_terms: D000767:Anesthesia, Epidural; D001034:Apgar Score; D001794:Blood Pressure / Q000187:drug effects*; D001835:Body Weight; D002585:Cesarean Section; D004305:Dose-Response Relationship, Drug; D004809:Ephedrine / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007022:Hypotension / Q000517:prevention & control*; D007231:Infant, Newborn; D007275:Injections, Intravenous; D008297:Male; D011247:Pregnancy; D012044:Regression Analysis; D014662:Vasoconstrictor Agents / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D014662:Vasoconstrictor Agents; D004809:Ephedrine