Chelucci G L, Brunet F, Dall'Ava-Santucci J, Dhainaut J F, Paccaly D, Armaganidis A, Milic-Emili J, Lockhart A
Dipartimento di Fisiopatologia Clinica, Università di Firenze, Italy.
Eur Respir J. 1991 Apr;4(4):458-64.
The time-course of thoracic volume changes (respiratory inductive plethysmograph) during relaxed expiration was studied in 11 intubated, paralysed, mechanically ventilated subjects. The semilog volume-time curves show that expiration is governed by two apparently separate mechanisms: one causes emptying of most of the expired volume (approximately 80%) with a time constant of 0.50 +/- 0.22 s for a baseline tidal volume of 0.44 +/- 0.12 l (mean +/- SD) and 0.37 +/- 0.14 s when the tidal volume is reduced (VTP); the other contributes a relatively small amount to the expired volume over a significantly longer time, the time constant amounting to 3.27 +/- 1.54 s for baseline VT and 2.95 +/- 1.65 s for VTp. The first mechanism probably reflects the standard elastic and flow resistive properties of the respiratory system, while the second, slower compartment, is probably an expression of the viscoelastic properties of the pulmonary and chest wall tissues.
对11名插管、麻痹且接受机械通气的受试者，研究了其在放松呼气过程中胸腔容积变化（呼吸感应体积描记法）的时间进程。半对数容积-时间曲线显示，呼气由两种明显不同的机制控制：一种机制导致大部分呼出容积（约80%）排空，对于基线潮气量为0.44±0.12升（均值±标准差）时，时间常数为0.50±0.22秒，潮气量减少（VTP）时为0.37±0.14秒；另一种机制在显著更长的时间内对呼出容积的贡献相对较小，基线潮气量时时间常数为3.27±1.54秒，VTP时为2.95±1.65秒。第一种机制可能反映了呼吸系统的标准弹性和流动阻力特性，而第二种较慢的部分可能是肺和胸壁组织粘弹性特性的一种表现。
