Neurocritical Care

, Volume 12, Issue 1, pp 17–23

Phenylephrine but not Ephedrine Reduces Frontal Lobe Oxygenation Following Anesthesia-Induced Hypotension

Authors

    • Department of AnesthesiaRigshospitalet 2041, University of Copenhagen
  • Patrice Brassard
    • Department of AnesthesiaRigshospitalet 2041, University of Copenhagen
  • Thomas B. Jørgensen
    • Department of AnesthesiaRigshospitalet 2041, University of Copenhagen
  • Niels H. Secher
    • Department of AnesthesiaRigshospitalet 2041, University of Copenhagen
Original Article

DOI: 10.1007/s12028-009-9313-x

Cite this article as:
Nissen, P., Brassard, P., Jørgensen, T.B. et al. Neurocrit Care (2010) 12: 17. doi:10.1007/s12028-009-9313-x

Abstract

Background

Vasopressor agents are used to correct anesthesia-induced hypotension. We describe the effect of phenylephrine and ephedrine on frontal lobe oxygenation (ScO2) following anesthesia-induced hypotension.

Methods

Following induction of anesthesia by fentanyl (0.15 mg kg−1) and propofol (2.0 mg kg−1), 13 patients received phenylephrine (0.1 mg iv) and 12 patients received ephedrine (10 mg iv) to restore mean arterial pressure (MAP). Heart rate (HR), MAP, stroke volume (SV), cardiac output (CO), and frontal lobe oxygenation (ScO2) were registered.

Results

Induction of anesthesia was followed by a decrease in MAP, HR, SV, and CO concomitant with an elevation in ScO2. After administration of phenylephrine, MAP increased (51 ± 12 to 81 ± 13 mmHg; P < 0.001; mean ± SD). However, a 14% (from 70 ± 8% to 60 ± 7%) reduction in ScO2 (P < 0.05) followed with no change in CO (3.7 ± 1.1 to 3.4 ± 0.9 l min−1). The administration of ephedrine led to a similar increase in MAP (53 ± 9 to 79 ± 8 mmHg; P < 0.001), restored CO (3.2 ± 1.2 to 5.0 ± 1.3 l min−1), and preserved ScO2.

Conclusions

The utilization of phenylephrine to correct hypotension induced by anesthesia has a negative impact on ScO2 while ephedrine maintains frontal lobe oxygenation potentially related to an increase in CO.

Keywords

Cerebral autoregulationCardiac outputArterial pressureNear infrared spectroscopyDrug effect

Abbreviations

CBF

Cerebral blood flow

CO

Cardiac output

HR

Heart rate

MAP

Mean arterial pressure

NIRS

Near infrared spectroscopy

ScO2

Frontal lobe cerebral oxygenation

SV

Stroke volume

Copyright information

© Springer Science+Business Media, LLC 2009