Kay B, Beatty P C, Healy T E, Accoush M E, Calpin M
Br J Anaesth. 1983 Dec;55(12):1239-47. doi: 10.1093/bja/55.12.1239.
Measurements of pressure and flow in five anaesthetic breathing systems were studied with various fresh gas flows (FGF) using volunteers, and mechanically simulated breathing. Pressure measurements were made at the patient connection and in the neck of the reservoir bag. A pneumotachograph was used to measure flow in the patient connection. The change in the work of breathing imposed by the circuit was derived from the pressure-volume graph and apportioned to stages of the breathing cycle. All the systems studied increased the work of breathing. Expiratory work was always increased more than inspiratory work. The additional work imposed on expiration and the total extra work imposed on breathing were further increased at FGF greater than the minimum clinical requirement.
使用志愿者并通过机械模拟呼吸，对五种麻醉呼吸系统在不同新鲜气体流量（FGF）下的压力和流量进行了测量。在患者连接端和储气囊颈部进行压力测量。使用呼吸速度描记器测量患者连接端的流量。由压力-容积图得出回路施加的呼吸功变化，并将其分配到呼吸周期的各个阶段。所研究的所有系统均增加了呼吸功。呼气功的增加总是大于吸气功。当新鲜气体流量大于最低临床需求时，呼气时额外增加的功以及呼吸时额外增加的总功会进一步增加。
