Center of Breath Research, Department of Anesthesiology, Intensive Care and Pain Therapy, Saarland University Medical Center, Homburg, Saarland, Germany.
Department of Outcomes Research, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, USA.
Acta Anaesthesiol Scand. 2020 Jul;64(6):759-765. doi: 10.1111/aas.13571. Epub 2020 Mar 23.
Volatile anesthetics potentially trigger malignant hyperthermia crises in susceptible patients. We therefore aimed to identify preparation procedures for the Draeger Primus that minimize residual concentrations of desflurane and sevoflurane with and without activated charcoal filtration.
A Draeger Primus test workstation was primed with 7% desflurane or 2.5% sevoflurane for 2 hours. Residual anesthetic concentrations were evaluated with five preparation procedures, three fresh gas flow rates, and three distinct applications of activated charcoal filters. Finally, non-exchangeable and autoclaved parts of the workstation were tested for residual emission of volatile anesthetics. Concentrations were measured by multicapillary column-ion mobility spectrometry with limits of detection/quantification being <1 part per billion (ppb) for desflurane and <2.5 ppb for sevoflurane.
The best preparation procedure included a flushing period of 10 minutes between removal and replacement of all parts of the ventilator circuit which immediately produced residual concentrations <5 ppm. A fresh gas flow of 10 L/minute reduced residual concentration as effectively as 18 L/minute, whereas flows of 1 or 5 L/minute slowed washout. Use of activated charcoal filters immediately reduced and maintained residual concentrations <5 ppm for up to 24 hours irrespective of previous workstation preparation. The fresh gas hose, circle system, and ventilator diaphragm emitted traces of volatile anesthetics.
In elective cases, presumably safe concentrations can be obtained by a 10-minute flush at ≥10 L/minute between removal and replacement all components of the airway circuit. For emergencies, we recommend using an activated charcoal filter.
挥发性麻醉剂有可能在易感患者中引发恶性高热危机。因此，我们旨在确定优化的德格尔普里默斯（Draeger Primus）准备程序，以最大程度地减少无论是否使用活性炭过滤时的残留七氟醚和地氟醚浓度。
德格尔普里默斯测试工作站用 7%七氟醚或 2.5%地氟醚预充 2 小时。通过五种准备程序、三种新鲜气流速率和三种不同的活性炭过滤器应用来评估残留麻醉剂浓度。最后，测试工作站不可更换和已消毒的部件是否有挥发性麻醉剂的残留排放。浓度通过多毛细管柱离子迁移谱法测量，七氟醚的检测/定量限为 <1 十亿分之一（ppb），地氟醚为 <2.5 ppb。
最佳准备程序包括在更换呼吸机回路的所有部件之前和之后进行 10 分钟的冲洗，这立即产生了<5 ppm 的残留浓度。10 L/分钟的新鲜气流与 18 L/分钟的新鲜气流一样有效地降低了残留浓度，而 1 或 5 L/分钟的气流则减缓了冲洗。使用活性炭过滤器可立即降低并维持残留浓度<5 ppm，最长可持续 24 小时，而与工作站的先前准备无关。新鲜气体软管、圆形系统和呼吸机膜片会释放出微量的挥发性麻醉剂。
在择期手术中，通过在移除和更换气道回路的所有部件之间进行≥10 L/分钟、10 分钟的冲洗，可以获得假定安全的浓度。对于紧急情况，我们建议使用活性炭过滤器。
