The effect of ephedrine and phenylephrine on BIS values during propofol anaesthesia.
BACKGROUND
The purpose of this study was to evaluate the effect of ephedrine and phenylephrine on propofol concentrations and bispectral index during propofol anesthesia.


METHODS
General anaesthesia was induced with propofol and was maintained with propofol (4 mg kg-1 h-1) and fentanyl. Vecuronium was used to facilitate the artificial ventilation of the lungs. Patients with systolic blood pressure > 90 mmHg were defined as the control group (n = 16). Patients who had to be treated for larger decreases in arterial blood pressure (systolic blood pressure 60, whereas no patient in the control or phenylephrine groups had bispectral index >60. There were no significant differences in propofol concentrations or cardiac output relative to baseline at 3 or 10 min after the administration of ephedrine or phenylephrine.


CONCLUSIONS
Ephedrine increases bispectral index values without decreasing propofol concentrations during general anesthesia.
Takizawa
D
D
Gunma University, Graduate School of Medicine, Department of Anesthesiology, Maebashi, Japan. d-takiza@bf6.so-net.ne.jp
Takizawa
E
E
Miyoshi
S
S
Kawahara
F
F
Ito
N
N
Ishizeki
J
J
Koizuka
S
S
Hiraoka
H
H
D000771:Anesthesia, Intravenous; D001794:Blood Pressure / Q000187:drug effects; D004569:Electroencephalography / Q000187:drug effects; D004576:Electromyography / Q000187:drug effects; D004809:Ephedrine / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D010656:Phenylephrine / Q000008:administration & dosage* / Q000009:adverse effects; D015742:Propofol / Q000008:administration & dosage* / Q000009:adverse effects
D010656:Phenylephrine; D004809:Ephedrine; D015742:Propofol