Hoffman W E, Edelman G
Anesthesiology Department, University of Illinois at Chicago, USA.
Anesth Analg. 1995 Oct;81(4):811-6. doi: 10.1097/00000539-199510000-00026.
We compared the anesthetic effects of desflurane and isoflurane using percent burst suppression of the electroencephalogram (EEG) as an end-point in 10 neurosurgical patients. The EEG was recorded from frontal leads and processed variables were analyzed as a function of increasing isoflurane and desflurane concentration with age and baseline delta EEG power (0.5-3.75 Hz) as independent variables. Isoflurane and desflurane (0.5, 1.0, 1.5, 2.0 minimum alveolar anesthetic concentration [MAC]) were incrementally administered until the EEG was quiesecent at least 40% of the time. Both anesthetics were evaluated separately in each patient. By analysis of variance, isoflurane and desflurane produced dose-related increments in burst suppression which were significantly affected by the age and baseline delta EEG of the patient. When isoflurane and desflurane were equated by MAC and adjusted for age, they produced statistically similar patterns of EEG burst suppression. Within subjects, a high degree of correlation was observed for percent burst suppression between equipotent levels of isoflurane and desflurane (r = 0.85; P < 0.05). Patients with baseline delta EEG power less than 80% of total power showed increases in delta EEG and decreases in median frequency with isoflurane and desflurane. Patients with baseline delta EEG power > 80% of total power produced no change in EEG frequency with increasing anesthesia but revealed a greater sensitivity to the development of burst suppression. These results show that isoflurane and desflurane produce similar EEG suppression in neurosurgical patients. If the EEG is initially slow, further slowing cannot be used to assess anesthetic depth.
我们以脑电图（EEG）爆发抑制百分比作为终点，比较了地氟烷和异氟烷对10例神经外科手术患者的麻醉效果。从额叶导联记录EEG，并将处理后的变量作为异氟烷和地氟烷浓度增加的函数进行分析，将年龄和基线δ波EEG功率（0.5 - 3.75 Hz）作为自变量。递增给予异氟烷和地氟烷（0.5、1.0、1.5、2.0最低肺泡有效浓度[MAC]），直至EEG至少40%的时间处于静息状态。每种麻醉药在每位患者中单独评估。通过方差分析，异氟烷和地氟烷产生与剂量相关的爆发抑制增加，这受到患者年龄和基线δ波EEG的显著影响。当异氟烷和地氟烷按MAC等效并根据年龄进行调整时，它们产生的EEG爆发抑制模式在统计学上相似。在受试者内部，观察到异氟烷和地氟烷等效水平之间的爆发抑制百分比具有高度相关性（r = 0.85；P < 0.05）。基线δ波EEG功率低于总功率80%的患者，使用异氟烷和地氟烷时δ波EEG增加，中位频率降低。基线δ波EEG功率>总功率80%的患者，随着麻醉加深EEG频率无变化，但对爆发抑制的发生更敏感。这些结果表明，异氟烷和地氟烷在神经外科手术患者中产生相似的EEG抑制。如果EEG最初较慢，则不能用进一步减慢来评估麻醉深度。
