Hemodynamic Effects of Ephedrine, Phenylephrine, and the Coadministration of Phenylephrine with Oxytocin during Spinal Anesthesia for Elective Cesarean Delivery

• DOI: 10.1097/aln.0b013e3181b437e0
• Publication Date: 2009-09-18T12:05:32Z
• Authors: Robert A. Dyer; Anthony R. Reed; Dominique van Dyk; Michelle J. Arcache; Owen Hodges; Carl J. Lombard; Jaime Greenwood; Michael F. James
• Keywords: Phenylephrine; Bolus (digestion)

Hemodynamic responses to vasopressors used during spinal anesthesia for elective Cesarean delivery, have not been well described. This study compared the effects of bolus phenylephrine and ephedrine on maternal cardiac output (CO). The hypothesis was that phenylephrine, but ephedrine, decreases CO when administered in response hypotension anesthesia.Forty-three patients were randomized receive 80 microg or 10 mg ephedrine. Both pulse wave form analysis transthoracic bioimpedance changes estimate stroke volume each patient. oxytocin also recorded. A subgroup 20 with plus after delivery.Mean maximum absolute significantly lower 150 s administration than (6.2 vs. 8.1 l/min, P = 0.001, 5.2 9.0 < 0.0001, respectively analysis, 6.3 0.01 4.5 6.7 changes). correlated heart rate changes. Coadministration obtunded oxytocin-induced systemic vascular resistance increases CO. Trends change similar using either monitor.Bolus reduced CO, decreased delivery. vasopressor administration, emphasizing importance as a surrogate indicator Coadministered hemodynamic oxytocin.