[Autoregulation of dynamic cerebral blood flow during hypotensive anesthesia with prostaglandin E1 or nitroglycerin].
BACKGROUND
Autoregulation of dynamic cerebral blood flow during hypotensive anesthesia is unclear. We examined the effects of hypotensive anesthesia with prostaglandin E1 (PGE1) or nitroglycerin (NTG) on autoregulation of the dynamic cerebral blood flow.


METHODS
Beat-by-beat mean arterial pressure (MAP) and blood flow velocity in the middle cerebral artery were measured before and during hypotensive anesthesia. The relationship between changes in MAP and cerebral blood flow velocity was evaluated by using the method of transfer function analysis. We calculated transfer function gain and coherence by cross-spectrum from autospectra of MAP and blood flow velocity in the low (0.07-0.2 Hz) and high (0.2-0.3 Hz) frequency ranges.


RESULTS
The gain in the both frequency ranges was unchanged during hypotensive anesthesia with PGE1. During hypotensive anesthesia with NTG, the gain in the high frequency range was unchanged, either. However, the gain in the low frequency range increased during hypotensive anesthesia with NTG. The value was significantly higher than in hypotensive anesthesia with PGE1.


CONCLUSIONS
These results suggest that hypotensive anesthesia with PGE1 maintains autoregulation of the dynamic cerebral blood flow, but NTG impairs the autoregulation in the low frequency range.
Kubota
Naoto
N
Department of Anesthesiology Nihon University, School of Medicine, Tokyo 173-8610.
Iwasaki
Ken-ichi
K
Ishikawa
Hisashi
H
Shiozawa
Tomoki
T
Kato
Jitsu
J
Ogawa
Setsuro
S
D000328:Adult; D000527:Alprostadil / Q000494:pharmacology; D000768:Anesthesia, General; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D006706:Homeostasis / Q000187:drug effects; D006801:Humans; D007023:Hypotension, Controlled; D008875:Middle Aged; D005996:Nitroglycerin / Q000009:adverse effects
D000527:Alprostadil; D005996:Nitroglycerin