Hemodynamic effects of simultaneous administration of intravenous ephedrine and spinal anesthesia for cesarean delivery.
OBJECTIVE
To evaluate the hemodynamic effects of an intravenous (IV) ephedrine bolus given simultaneously with spinal anesthesia for cesarean delivery.


METHODS
Randomized, prospective, double-blind study.


METHODS
Tertiary-care academic medical center.


METHODS
40 ASA physical status I and II nonlaboring women undergoing elective cesarean delivery of term, uncomplicated, singleton pregnancies.


METHODS
After a 10 mL/kg IV lactated Ringers bolus given over 15 minutes, patients simultaneously received an IV dose of 2 mL (10 mg) ephedrine or 2 mL saline, and an intrathecal dose of 12 mg (1.6 mL 0.75%) bupivacaine with 10 microg of fentanyl. Hypotension, defined as a 20% decrease in mean arterial pressure (MAP), was treated with 10-mg IV doses of ephedrine.


METHODS
Hemodynamic (heart rate and MAP) and non-invasive thoracic impedance (cardiac index, stroke index, and systemic vascular resistance index) measurements at baseline and at 1-minute intervals until the time of delivery. Total fluid, supplemental ephedrine, and Apgar scores were recorded. Data were evaluated using analysis of variance (ANOVA), ANOVA for repeated measures, and Mann-Whitney U-tests where appropriate, with p < 0.05 considered significant.


RESULTS
Significant changes from baseline in MAP, systemic vascular resistance index, heart rate, and cardiac index were observed in both groups after spinal anesthesia. However, there were no differences between the ephedrine and saline groups in the incidence and severity of change from the baseline. The overall incidence of hypotension was 70% in both groups. No difference in total fluid or supplemental ephedrine use was observed.


CONCLUSIONS
10 mg of IV ephedrine given at the time of spinal anesthesia, and after a 10 mL/kg lactated Ringers fluid bolus, does not diminish the incidence or severity of hypotension in parturients undergoing cesarean delivery.
Tsen
L C
LC
Department of Anesthesia, Perioperative and Pain Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. lctsen@bics.bwh.harvard.edu
Boosalis
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P
Segal
S
S
Datta
S
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Bader
A M
AM
D000328:Adult; D000775:Anesthesia, Spinal; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D002045:Bupivacaine / Q000008:administration & dosage / Q000494:pharmacology; D002585:Cesarean Section; D004311:Double-Blind Method; D004809:Ephedrine / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007275:Injections, Intravenous; D011247:Pregnancy; D011446:Prospective Studies; D014655:Vascular Resistance / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000494:pharmacology*
D000779:Anesthetics, Local; D014662:Vasoconstrictor Agents; D004809:Ephedrine; D002045:Bupivacaine