Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, 2200 College Station Road, Athens, GA 30605, USA.
Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, 2200 College Station Road, Athens, GA 30605, USA.
Res Vet Sci. 2023 Jun;159:66-71. doi: 10.1016/j.rvsc.2023.04.008. Epub 2023 Apr 17.
Sedation and anesthesia alter the raw electroencephalogram (EEG). Interpretation of the EEG is facilitated by measuring the patient state index (PSI), visual inspection of density spectral arrays (DSA), and power density analysis of the delta (0.1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), and beta plus gamma (12-40 Hz) frequency bands. Baseline data were recorded in six male intact Beagles before sedation with intravenous acepromazine (0.03 mg/kg) and hydromorphone (0.1 mg/kg). Anesthesia was induced and maintained for five minutes with intravenous propofol (1.5 mg/kg over five seconds followed by 12 mg/kg/h). Additional propofol (0.5-1.0 mg/kg and up to 16.7 mg/kg/h) was administered within this time frame if the PSI was above 50. The effects of sedation and anesthesia were evaluated with a mixed-effect model followed by Dunnett's test (alpha = 0.05). The average baseline PSI (95% confidence interval) was 93.0 (91.4-94.6) and decreased on sedation [88.7 (86.0-91.3); p = 0.039] and anesthesia [44.5 (40.8-48.2); p < 0.001]. The awake DSA showed dense power in all bands. The power density decreased with sedation. During anesthesia, the power density was reduced in frequencies above 12 Hz. The baseline power density on the delta, theta, alpha, and beta plus gamma bands was higher than sedation (p < 0.007). Compared to baseline, anesthesia had lower power on delta, and beta plus gamma bands (p < 0.002). The interpretation in awake, sedated, and anesthetized dogs of the EEG can be facilitated by processing and generating PSI and DSA.
镇静和麻醉会改变原始脑电图（EEG）。通过测量患者状态指数（PSI）、密度谱数组（DSA）的视觉检查以及 delta（0.1-4 Hz）、theta（4-8 Hz）、alpha（8-12 Hz）和 beta plus gamma（12-40 Hz）频段的功率密度分析，可方便地对 EEG 进行解释。在静脉注射乙酰丙嗪（0.03 mg/kg）和氢吗啡酮（0.1 mg/kg）镇静前，记录了六只雄性完整比格犬的基线数据。用静脉注射异丙酚（1.5 mg/kg 持续五秒，然后 12 mg/kg/h）诱导并维持麻醉五分钟。如果 PSI 高于 50，则在此时间段内给予额外的异丙酚（0.5-1.0 mg/kg 和高达 16.7 mg/kg/h）。使用混合效应模型和 Dunnett 检验（alpha = 0.05）评估镇静和麻醉的效果。平均基线 PSI（95%置信区间）为 93.0（91.4-94.6），镇静后下降[88.7（86.0-91.3）；p = 0.039]，麻醉后下降[44.5（40.8-48.2）；p < 0.001]。清醒时的 DSA 显示所有频段的功率均密集。随着镇静的进行，功率密度降低。麻醉期间，12 Hz 以上频率的功率密度降低。delta、theta、alpha 和 beta plus gamma 频段的基线功率密度高于镇静时（p < 0.007）。与基线相比，麻醉时 delta 和 beta plus gamma 频段的功率较低（p < 0.002）。在清醒、镇静和麻醉犬中，通过处理和生成 PSI 和 DSA，可以方便地解释 EEG。
