Department of Anesthesiology, Hospital Universitario Virgen de la Victoria, Campus Universitario Teatinos, C.P. 29010, Malaga, Spain.
J Clin Monit Comput. 2012 Jun;26(3):171-5. doi: 10.1007/s10877-012-9351-3. Epub 2012 Mar 20.
Small changes in the frequency of the electromyography could reflect an inadequate anesthetic or analgesic level, and it could be more specific than the hemodynamic monitors. The Datex-Ohmeda S/5 Entropy Module includes information about the electromyographic activity of the face muscles (response entropy--RE). The aim of our study is compare entropy and BIS ability to detect a nociceptive stimulus during a sevoflurane anesthesia. We designed an observational, prospective and descriptive study that included 20 patients. We performed sevoflurane anaesthesia induction, the end-tidal was kept at 3 and 4 %, during 15 min at each concentration, with no analgesic drug and no neuromuscular blocking agent, and we applied a nociceptive stimulus: tetanus 100 Hz, during 5 s. We set the standard monitorization, BIS, RE, and state entropy (SE) along the study. There was a significant difference between RE and SE post-noxious stimulus values at 3 and 4 % end-tidal sevoflurane (p < 0.05). Only RE changed significantly at the moment of the noxious stimulation at both sevoflurane concentrations studied (p < 0.05). In patients under general anesthesia only carried out with sevoflurane at concentrations that inhibit the movement to painful stimuli, the RE is a single parameter able to detect variations after the nociceptive stimulation.
肌电图频率的微小变化可能反映出麻醉或镇痛水平不足，而且比血流动力学监测器更为具体。Datex-Ohmeda S/5 熵模块包含面部肌肉肌电图活动的信息（反应熵-RE）。我们研究的目的是比较熵和 BIS 检测七氟醚麻醉期间伤害性刺激的能力。我们设计了一项观察性、前瞻性和描述性研究，纳入了 20 名患者。我们进行七氟醚麻醉诱导，呼气末浓度保持在 3%和 4%，在每个浓度下持续 15 分钟，不使用镇痛药物和神经肌肉阻滞剂，并应用伤害性刺激：100 Hz 强直刺激，持续 5 s。我们在研究过程中设置了标准监测、BIS、RE 和状态熵（SE）。在 3%和 4%呼气末七氟醚时，RE 和 SE 在伤害性刺激后的数值之间存在显著差异（p<0.05）。只有在两种研究的七氟醚浓度下，在伤害性刺激时，RE 才发生显著变化（p<0.05）。在仅使用七氟醚进行全身麻醉的患者中，RE 是唯一能够在伤害性刺激后检测到变化的单一参数。
