Marx T, Fröba G, Bäder S, Villwock J, Georgieff M
University of Ulm, Clinic of Anaesthesiology, Germany.
Acta Anaesthesiol Scand. 1996 Feb;40(2):275-81. doi: 10.1111/j.1399-6576.1996.tb04432.x.
Improvement of working conditions and anaesthesia with closed systems includes reduction of gas leaks during anaesthesia. One source of contamination is the permeation of gases through plastic materials. The volume of gas permeating through a polymer depends on its molecular structure, the solubility and the diffusion coefficient.
We designed an experimental set-up to measure the permeation rates of nitrous oxide, enflurane and isoflurane through components of the anaesthetic ventilator made of silicone, latex, rubber and polyvinylchloride (PVC). Reservoir bags, ventilation tubes and endotracheal tubes were investigated.
The highest permeation rates of anaesthetic gases were observed with silicone materials. Permeation through silicone exceeded that of the least permeable material by more than 10.000 times. By summarizing the permeation rates of the single items, the use of silicone increases the anaesthetic system's leakage rate by 4 ml/min, which means an increase of 18% in a modern anaesthetic ventilator and of 31% in a closed system.
The highest permeation rates were found for nitrous oxide through silicone, although nitrous oxide has a known low solubility in plastic materials. The result demonstrates the dependency of the leakage rate on the diffusibility. The leakage of anaesthetic gases caused by silicone items does not alone lead to unacceptable pollution of operating theatres. To minimize the total leakage rates of minimal-flow-systems, however, plastic materials with low solubility and low diffusion coefficients have to be used.
采用封闭系统改善工作条件及麻醉效果包括减少麻醉期间的气体泄漏。污染的一个来源是气体透过塑料材料的渗透。透过聚合物的气体体积取决于其分子结构、溶解度和扩散系数。
我们设计了一个实验装置，以测量氧化亚氮、安氟醚和异氟醚透过由硅酮、乳胶、橡胶和聚氯乙烯（PVC）制成的麻醉呼吸机组件的渗透率。对贮气囊、通气管和气管内导管进行了研究。
观察到硅酮材料对麻醉气体的渗透率最高。硅酮材料的渗透率比渗透率最低的材料高出10000倍以上。通过汇总单个项目的渗透率，使用硅酮会使麻醉系统的泄漏率增加4毫升/分钟，这意味着在现代麻醉呼吸机中增加18%，在封闭系统中增加31%。
尽管氧化亚氮在塑料材料中的溶解度较低，但通过硅酮材料的氧化亚氮渗透率最高。结果表明泄漏率取决于扩散性。硅酮制品引起的麻醉气体泄漏本身不会导致手术室不可接受的污染。然而，为了使微流量系统的总泄漏率降至最低，必须使用溶解度低和扩散系数低的塑料材料。
