Hargasser S, Breinbauer B, Kling M, Mielke L, Entholzner E, Malek A, Rust M, Hipp R
Institut für Anaesthesiologie, Technischen Universität München, Klinikum rechts der Isar.
Anaesthesiol Reanim. 1994;19(6):149-54.
So far the anaesthetic technique of the closed circuit system in clinical routine could not be used adequately, because suitable mixtures of respiration gas components were not available and the maintenance of a sufficient gas volume in the anaesthetic circle system was not possible with the standard anaesthesia machines. The anaesthesia machine PhysioFlex was especially constructed to deliver anaesthetics in a closed circuit system. In this anaesthesia machine the concentrations of the respiratory gases and the gas volume in the circle system are automatically controlled by a feedback mechanism. We compared the closed circuit system (CC group), with a high-flow system (HF group) and a low-flow system (LF group)--each system on 10 patients. It was noted that the respiratory gas concentrations were adjustable and held constant to a greater degree precise in the circuit system. After the induction the desired inspiratory oxygen-concentration was reached within 5 minutes, the expiratory isoflurane-concentration within 10 minutes in the CC group and was maintained reliable. The consumption of liquid isoflurane was 12.9 ml/h in the HF group, 7.5 ml/h in the LF group and 5.3 ml/h in the CC group. The anaesthetic management was possible without any problems in all three groups.
到目前为止,临床常规中闭路系统的麻醉技术未能得到充分应用,因为无法获得合适的呼吸气体成分混合物,且使用标准麻醉机无法在麻醉环路系统中维持足够的气体量。麻醉机PhysioFlex是专门为在闭路系统中输送麻醉剂而设计的。在这台麻醉机中,环路系统中的呼吸气体浓度和气体量由反馈机制自动控制。我们将闭路系统(CC组)与高流量系统(HF组)和低流量系统(LF组)进行了比较——每个系统各用于10名患者。值得注意的是,在环路系统中呼吸气体浓度的可调节性更强,且能更精确地保持恒定。诱导后,CC组在5分钟内达到了所需的吸入氧浓度,在10分钟内达到了呼出异氟烷浓度,并能可靠地维持。HF组液体异氟烷的消耗量为12.9毫升/小时,LF组为7.5毫升/小时,CC组为5.3毫升/小时。三组均能顺利进行麻醉管理。