Meiser A, Bomberg H, Volk T, Groesdonk H V
Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum des Saarlandes, Kirrberger Str. 1, 66421, Homburg/Saar, Deutschland.
Anaesthesist. 2017 Apr;66(4):274-282. doi: 10.1007/s00101-017-0269-5.
The circle system has been in use for more than 100 years, whereas the first clinical application of an anaesthetic reflector was reported just 15 years ago. In the circle system, all breathing gas is rebreathed after carbon dioxide absorption. A reflector, on the other hand, with the breathing gas flowing to and fro, specifically retains the anaesthetic during expiration and resupplies it during the next inspiration. A high reflection efficiency (number of molecules resupplied/number of molecules exhaled, RE 80-90%) decreases consumption. In analogy to the fresh gas flow of a circle system, pulmonary clearance ((1-RE) × minute ventilation) defines the opposition between consumption and control of the concentration.It was not until reflection systems became available that volatile anaesthetics were used routinely in some intensive care units. Their advantages, such as easy handling, and better ventilatory capabilities of intensive care versus anaesthesia ventilators, were basic preconditions for this. Apart from AnaConDa™ (Sedana Medical, Uppsala, Sweden), the new MIRUS™ system (Pall Medical, Dreieich, Germany) represents a second, more sophisticated commercially available system.Organ protective effects, excellent control of sedation, and dose-dependent deep sedation while preserving spontaneous breathing with hardly any accumulation or induction of tolerance, make volatile anaesthetics an interesting alternative, especially for patients needing deep sedation or when intravenous drugs are no longer efficacious.But obviously, the outcome is most important. We know that deep intravenous sedation increases mortality, whereas inhalational sedation could prove beneficial. We now need prospective clinical trials examining mortality, but also the psychological outcome of those most critically ill patients sedated by inhalation or intravenously.
循环系统已使用超过100年，而麻醉反射器的首次临床应用仅在15年前才有报道。在循环系统中，所有呼吸气体在二氧化碳吸收后再循环。另一方面，对于反射器，随着呼吸气体来回流动，它在呼气时专门保留麻醉剂，并在下一次吸气时重新供应。高反射效率（重新供应的分子数/呼出的分子数，RE 80 - 90%）可降低消耗量。类似于循环系统的新鲜气体流量，肺清除率（(1 - RE)×分钟通气量）定义了消耗量与浓度控制之间的对抗关系。直到反射系统出现，挥发性麻醉剂才在一些重症监护病房中常规使用。其优点，如易于操作，以及重症监护呼吸机相对于麻醉呼吸机更好的通气能力，是实现这一点的基本前提条件。除了AnaConDa™（瑞典乌普萨拉的Sedana Medical公司），新型MIRUS™系统（德国德赖艾希的颇尔医疗公司）代表了第二种更先进的商用系统。器官保护作用、出色的镇静控制以及在保持自主呼吸的同时剂量依赖性的深度镇静，几乎没有蓄积或耐受性诱导，使得挥发性麻醉剂成为一种有趣的选择，特别是对于需要深度镇静的患者或静脉药物不再有效的情况。但显然，结果是最重要的。我们知道深度静脉镇静会增加死亡率，而吸入镇静可能被证明是有益的。我们现在需要前瞻性临床试验来研究死亡率，以及那些通过吸入或静脉进行镇静的重症患者的心理结果。
