Chelucci G L, Dall' Ava-Santucci J, Dhainaut J F, Chelucci A, Allegra A, Paccaly D, Brunet F, Milic-Emili J, Lockhart A
Dipartimento di Fisiopatologia Clinica, Università di Firenze, Italia.
Eur Respir J. 1993 Jun;6(6):785-90.
The time-course of volume change during passive expiration preceded by an end-inspiratory hold was studied with a biexponential model in six adult respiratory distress syndrome (ARDS) patients. We measured the initial volumes and time constants of the fast (tau 1), and the slow (tau 2) compartments of expiration, as well as the static elastance of the respiratory system. The results were compared to those of 11 normal subjects. We observed that: 1) the biexponential model fitted closely the volume decay; 2) the fast compartment was responsible for 81 +/- 7% (ARDS) versus 84 +/- 10% (controls) of the total volume exhaled, with tau 1 = 0.35 +/- 0.11 s (ARDS) versus 0.50 +/- 0.22 s (controls); 3) the slow compartment contributed only 19 +/- 6% (ARDS) versus 16 +/- 7% (controls), with tau 2 = 4.67 +/- 2.38 s (ARDS) versus 3.27 +/- 1.54 s (controls); and 4) static elastance was higher in ARDS patients. The findings could be explained in terms of a four parameter viscoelastic model of the respiratory system.
采用双指数模型研究了6例成人呼吸窘迫综合征（ARDS）患者在吸气末屏气后被动呼气过程中的容积变化时程。我们测量了呼气快速（τ1）和慢速（τ2）部分的初始容积和时间常数，以及呼吸系统的静态弹性。将结果与11名正常受试者的结果进行比较。我们观察到：1）双指数模型与容积衰减拟合紧密；2）快速部分占呼出总体积的81±7%（ARDS），而对照组为84±10%，τ1 = 0.35±0.11秒（ARDS），对照组为0.50±0.22秒；3）慢速部分仅占19±6%（ARDS），对照组为16±7%，τ2 = 4.67±2.38秒（ARDS），对照组为3.27±1.54秒；4）ARDS患者的静态弹性更高。这些发现可以用呼吸系统的四参数粘弹性模型来解释。
