The effect of sevoflurane on dynamic cerebral blood flow autoregulation assessed by spectral and transfer function analysis.
Sevoflurane reduces autonomic neural control, which plays a significant role in cerebral autoregulation. Therefore, we hypothesized that sevoflurane influences cerebral autoregulation. We investigated the effects of sevoflurane on dynamic cerebral blood flow (CBF) autoregulation by using spectral and transfer function analysis between blood pressure variability and CBF velocity variability. Eleven healthy male subjects received 0.5%, 1.0%, and 1.5% sevoflurane via facemask. Dynamic cerebral autoregulation was evaluated by transfer function gain, phase, and coherence between CBF velocity in the middle cerebral artery measured by transcranial Doppler, and blood pressure in the radial artery. Coherence in the very low-frequency range (0.02-0.07 Hz) increased above 0.5 during administration of 0.5% and 1.0% sevoflurane. Transfer function gain in this frequency range (0.02-0.07 Hz), as an index of dynamic cerebral autoregulation, increased significantly with 0.5% and 1.0% sevoflurane. Transfer function gain and coherence in the low- and high-frequency ranges, however, remained unchanged during administration of sevoflurane. These results suggest that sevoflurane impairs dynamic cerebral autoregulation in the very-low-frequency range even with small concentrations, whereas dynamic cerebral autoregulation in the low- and high-frequency ranges remained unchanged.
Ogawa
Yojiro
Y
Department of Dental Anesthesiology, Nihon University School of Dentistry, Nihon University School of Medicine, Tokyo, Japan.
Iwasaki
Ken-ichi
K
Shibata
Shigeki
S
Kato
Jitsu
J
Ogawa
Setsuro
S
Oi
Yoshiyuki
Y
D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure; D002536:Cerebral Arteries; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D006706:Homeostasis / Q000187:drug effects*; D006801:Humans; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology*; D000077149:Sevoflurane; D017585:Ultrasonography, Doppler, Transcranial
D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane