Ungerer M J
Can Anaesth Soc J. 1978 Mar;25(2):122-4. doi: 10.1007/BF03005068.
The efficiency of the Bain system has been compared with that of the Magill system in ten conscious subjects breathing spontaneously. Air was supplied at fresh flow rates of 150 ml/kg and decreased stepwise at four-minute intervals until a flow of 50 ml/kg was attained. Expired minute volume and end-tidal carbon dioxide concentrations were measured. No rebreathing could be demonstrated with the Magill stystem at flow rates above approximately 70 ml/kg. In contrast, rebreathing was evident at all flow rates with the Bain system. It is concluded that acceptable carbon dioxide levels during spontaneous breathing with the Bain circuit can only be maintained by considerable active hyperventilation when using flow rates of 150 ml/kg and less.
在十名自主呼吸的清醒受试者中，对贝恩系统和马吉尔系统的效率进行了比较。以150毫升/千克的新鲜气流速率供应空气，并每隔四分钟逐步降低，直至达到50毫升/千克的气流速率。测量呼出分钟通气量和呼气末二氧化碳浓度。当气流速率高于约70毫升/千克时，马吉尔系统未显示出再呼吸现象。相比之下，贝恩系统在所有气流速率下均有明显的再呼吸现象。得出的结论是，在使用150毫升/千克及更低的气流速率时，使用贝恩回路进行自主呼吸期间，只有通过相当程度的主动过度通气才能维持可接受的二氧化碳水平。
