Wiesner G, Wild K, Merz M, Hobbhahn J
Klinik für Anästhesiologie, Universität Regensburg.
Anasthesiol Intensivmed Notfallmed Schmerzther. 1995 Aug;30(5):290-6. doi: 10.1055/s-2007-996494.
Sevoflurane is a "new" volatile inhaled anaesthetic currently undergoing phase III clinical trials in Europe and USA. Owing to the low blood solubility, rapid induction of anaesthesia and emergence from anaesthesia would be expected. In this study, we compared emergence times and haemodynamics in patients receiving either sevoflurane or enflurane. Furthermore, all adverse experiences were recorded, and the relationship to the drug administered was rated.
Thirty ASA physical status I and II patients were studied in an open, prospective and randomised clinical trial. Anaesthesia was induced with fentanyl, thiopentone and vecuronium for facilitating endotracheal intubation. Anaesthesia was maintained with sevoflurane or enflurane, 60% nitrous oxide in oxygen and additional doses of fentanyl (1-2 micrograms/kg/h). ECG, blood pressure (non-invasive), inspiratory and end-tidal concentrations of sevoflurane or enflurane were monitored continuously. At the end of surgery, administration of sevoflurane or enflurane and nitrous oxide stopped without tapering and emergence times were recorded. All adverse experiences which occurred until the third postoperative day were recorded and the relationship to the inhaled anaesthetic was rated as "none", "unlikely", "possible", "probable" or "highly probable".
With the exception of the end-tidal concentration at the end of surgery and the mean inspiratory and end-tidal concentrations, which were higher for sevoflurane, the two patient groups were comparable. Pulmonary elimination was significantly faster and emergence time was significantly shorter (5 vs. 9 minutes) with sevoflurane. Emergence time did not correlate with the duration of anaesthetic exposure (MAC hours) for sevoflurane. There was no difference in the time courses of heart rate and mean arterial blood pressure between sevoflurane and enflurane. No adverse experiences with a "probable" or "highly probable" relationship to the inhaled anaesthetic were observed.
Emergence time after inhalation anaesthesia depends on (alveolar) ventilation, blood-gas solubility coefficient and, at least for enflurane and isoflurane, on the dose applied (MAC hours). There is no positive correlation between emergence time and dose applied for sevoflurane. Due to the lower blood-gas solubility coefficient (0.6-0.7 for sevoflurane vs. 1.8 for enflurane) pulmonary elimination is faster and emergence time is shorter with sevoflurane. Supplementing inhalation anaesthesia with fentanyl, there is no difference in the time courses of heart rate and mean arterial blood pressure between sevoflurane and enflurane.
七氟醚是一种“新型”挥发性吸入麻醉剂，目前正在欧美进行Ⅲ期临床试验。由于其血液溶解度低，预计麻醉诱导和苏醒迅速。在本研究中，我们比较了接受七氟醚或恩氟醚患者的苏醒时间和血流动力学。此外，记录所有不良事件，并对其与所用药物的关系进行评估。
在一项开放、前瞻性、随机临床试验中对30例ASA身体状况为Ⅰ级和Ⅱ级的患者进行研究。用芬太尼、硫喷妥钠和维库溴铵诱导麻醉以利于气管插管。用七氟醚或恩氟醚、60%氧化亚氮加氧气以及额外剂量的芬太尼（1 - 2微克/千克/小时）维持麻醉。持续监测心电图、血压（无创）、七氟醚或恩氟醚的吸气和呼气末浓度。手术结束时，七氟醚或恩氟醚及氧化亚氮的给药不经逐步减量直接停止，并记录苏醒时间。记录直至术后第3天发生的所有不良事件，并将其与吸入麻醉剂的关系评估为“无”“不太可能”“可能”“很可能”或“极有可能”。
除了手术结束时的呼气末浓度以及七氟醚的平均吸气和呼气末浓度较高外，两组患者具有可比性。七氟醚的肺部清除明显更快，苏醒时间明显更短（5分钟对9分钟）。七氟醚的苏醒时间与麻醉暴露时间（MAC小时）无关。七氟醚和恩氟醚之间心率和平均动脉血压的时间过程无差异。未观察到与吸入麻醉剂有“很可能”或“极有可能”关系的不良事件。
吸入麻醉后的苏醒时间取决于（肺泡）通气、血气溶解度系数，至少对于恩氟醚和异氟醚而言，还取决于所用剂量（MAC小时）。七氟醚的苏醒时间与所用剂量之间无正相关。由于七氟醚的血气溶解度系数较低（七氟醚为0.6 - 0.7，恩氟醚为1.8），七氟醚的肺部清除更快，苏醒时间更短。用芬太尼补充吸入麻醉时，七氟醚和恩氟醚之间心率和平均动脉血压的时间过程无差异。
