Lorino A M, Benhamou D, Lorino H, Harf A
Bull Eur Physiopathol Respir. 1986 Jan-Feb;22(1):81-4.
In order to monitor respiratory mechanics in anesthetized ventilated subjects, an automated method was developed and tested on a physical model. The model was composed of an endotracheal tube (curvilinear resistance) coupled to a rigid air-filled box (elastance). Theoretical resistance was determined during steady-state flow experiments and theoretical elastance was estimated from the dimensions of the box. The physical model was connected to a volume-cycled ventilator. Pressure (P) and air flow (V) were measured at the outlet of the tube, and the time integral V of V was calculated. Elastance (E) and curvilinear resistance (R + K/V/) were identified by multiple linear regression analysis, for each ventilatory cycle, according to equation P = EV + RV + K/V/V. When linear regression analysis of P on V, V and /V/V was performed over the entire ventilatory cycle, E was found equal to its estimate, whereas R and K appeared different from their theoretical values. In order to improve determination of R and K, resistive pressure (Pr = P - EV) was calculated using the previously obtained value of E, and multiple linear regression of Pr on V and /V/V was performed over different fractions of the ventilatory cycle. When determined over the expiratory phase corresponding to decreasing flows, R and K were found close to their expected values. Such a method to calculate elastance and curvilinear resistance should prove convenient and efficient in measuring respiratory mechanics during mechanical ventilation.
为了监测麻醉通气受试者的呼吸力学，开发了一种自动化方法并在物理模型上进行了测试。该模型由连接到刚性充气箱（弹性）的气管内导管（曲线阻力）组成。在稳态流动实验中确定理论阻力，并根据箱子尺寸估算理论弹性。将物理模型连接到容量控制通气机。在导管出口处测量压力（P）和气流（V），并计算V的时间积分V。根据方程P = EV + RV + K/V/V，通过多元线性回归分析确定每个通气周期的弹性（E）和曲线阻力（R + K/V/）。当在整个通气周期对P与V、V和/V/V进行线性回归分析时，发现E等于其估计值，而R和K与其理论值不同。为了改进R和K的测定，使用先前获得的E值计算阻力压力（Pr = P - EV），并在通气周期的不同部分对Pr与V和/V/V进行多元线性回归。当在对应于流量下降的呼气阶段进行测定时，发现R和K接近其预期值。这种计算弹性和曲线阻力的方法在机械通气期间测量呼吸力学方面应证明是方便且有效的。
