Effect of nitrous oxide on EEG power spectrum evored by enflurane
- VernacularTitle:氧化亚氮对安氟醚脑电功率谱的影响
- Author:
Xiao HU
;
Meijin MENG
;
Xinmin WU
- Publication Type:Journal Article
- Keywords:
Power spectral analysis Enflurane Nitrous oxide
- From:
Chinese Journal of Anesthesiology
1995;0(10):-
- CountryChina
- Language:Chinese
-
Abstract:
The effects of different concentrations of enflurane and enflurane/nitrous oxide on EEG in 20 patients (ASA grade Ⅰ) were studied during elective surgery. They were divided randomly into two groups:enflurane (E) group (n=10) and enflurane/nitrous oxide (EN) group (n= 10). Anesthesia was induced by inhaling enflurane or enflurane/60% nitrous oxide. After intubation patients were venti lated mechanically to maintain P_(ET)CO_2 4.27—4.93 kPa, Two-leads EEG monitor was used during operation. 95% spectral edge frequency (SEF),MAP and HR were recorded in group E at 0.5,0.8,1.0,1.3 and 1.5 MAC, and in group EN at 0.8,1, 0,1.3,1.5,1.8 and 2.0 MAC. SEF decreased in linear manner,but MAP insignificantly changed as enflurane level increased. SEF was smaller in group E than that in group EN under the same additive MAC value, In raw EEG,patients in group E had spike wave at more than Ⅰ.0 MAC,but there was no spike wave in group EN. So enflurane/nitrous oxide anesthesia is more proper because nitrous oxide diminishs the undesirable effects of enflurane on brain during deeper anesthesia. The simple additive MAC value may not reflect the exact anesthesia level when nitrous oxide is used in combination, but SRF can do it.
