Ooi R, Pattison J, Soni N
Magill Department of Anaesthetics, Westminster Hospital, London.
Anaesthesia. 1993 Jul;48(7):599-603. doi: 10.1111/j.1365-2044.1993.tb07126.x.
The additional work attributable to breathing through five Mapleson A anaesthetic breathing systems (Magill, Lack, Parallel Lack, Humphrey ADE and Enclosed Magill) was studied using a lung model. With all five systems, the additional work was found to be a function of fresh gas flow, respiratory flow as well as system geometry. Within the range of fresh gas flow and respiratory flow studied, the additional work ranged between 80 mJ.l-1 and 182 mJ.l-1. Expiratory work was always greater than the inspiratory workload. Increasing fresh gas inflow into the system increases expiratory work, both resistive and elastic components. The Magill system posed the least work expenditure. The values for the additional work obtained with the lung model were of the same order of magnitude when measurements were taken in volunteers.
使用肺模型研究了通过五种Mapleson A麻醉呼吸系统（Magill、Lack、Parallel Lack、Humphrey ADE和封闭式Magill）呼吸所产生的额外功。对于所有这五种系统，发现额外功是新鲜气体流量、呼吸流量以及系统几何形状的函数。在所研究的新鲜气体流量和呼吸流量范围内，额外功在80 mJ·l⁻¹至182 mJ·l⁻¹之间。呼气功总是大于吸气功。增加进入系统的新鲜气体流量会增加呼气功，包括阻力和弹性成分。Magill系统的功消耗最少。当在志愿者身上进行测量时，用肺模型获得的额外功值处于相同的数量级。
