Jonsson L O, Zetterström H
Department of Anaesthesiology and Intensive Care, Ostersund Hospital, Sweden.
Acta Anaesthesiol Scand. 1989 Jan;33(1):71-4. doi: 10.1111/j.1399-6576.1989.tb02863.x.
The validity of the Stenqvist-Sonander formula for calculating the end-expiratory fraction of carbon dioxide (FACO2) in the coaxial Mapleson D (Bain) systems was evaluated using a lung model for simulated spontaneous breathing with an optional respiratory wave form. Two different respiratory flow patterns were used, one representing relaxed breathing in a volunteer and one resembling the respiration found in halothane anaesthesia. Each pattern was used with five different fresh gas flows and three different respiratory rates. The formula was found to be quite accurate when the flow pattern of an awake volunteer was simulated, but it underestimated the observed FETCO2 value by about 10% in halothane breathing. It is concluded that the formula can be recommended for use in theoretical and educational situations but that it is too complicated for application in clinical practice.
使用具有可选呼吸波形的肺模型模拟自主呼吸，评估了Stenqvist-Sonander公式在同轴Mapleson D（Bain）系统中计算呼气末二氧化碳分数（FACO2）的有效性。使用了两种不同的呼吸流量模式，一种代表志愿者的轻松呼吸，另一种类似于氟烷麻醉时的呼吸。每种模式与五种不同的新鲜气体流量和三种不同的呼吸频率一起使用。发现当模拟清醒志愿者的流量模式时，该公式相当准确，但在氟烷呼吸中，它低估了观察到的FETCO2值约10%。结论是，该公式可推荐用于理论和教育场景，但对于临床实践应用来说过于复杂。
