Whiteley J P, Gavaghan D J, Hahn C E
Nuffield Department of Anaesthetics, University of Oxford, Radcliffe Infirmary, Woodstock Road, OX2 6HE, Oxford, UK.
Respir Physiol. 2001;124(1):65-83. doi: 10.1016/s0034-5687(00)00185-7.
The tidal breathing model conservation of mass equations for the sinewave technique have been described for a homogeneous alveolar compartment by Gavaghan and Hahn, 1996 [Gavaghan, D.J., Hahn, C.E.W., 1996. A tidal breathing model of the forced inspired gas sinewave technique. Respir. Physiol. 106, 209-221]. We develop these equations first to a multi-discrete alveolar compartment lung model and then to a lung model with a continuous distribution of volume, ventilation and perfusion. The effect on the output parameters of a multi-compartment model is discussed, and the results are compared to those derived from the conventional continuous-ventilation model. Using the barely soluble gas argon as the tracer gas, an empirical index of alveolar inhomogeneity is presented which uses the end-expired and mixed-expired partial pressures on each breath. This index distinguishes between a narrow unimodal distribution of ventilation-volume, a wide unimodal distribution of ventilation-volume and a bimodal distribution of ventilation-volume. By using Monte Carlo simulations, this index is shown to be stable to experimental error of realistic magnitude.
加瓦汉和哈恩在1996年描述了正弦波技术的潮式呼吸模型质量守恒方程，用于均匀肺泡腔[加瓦汉，D.J.，哈恩，C.E.W.，1996。强迫吸气气体正弦波技术的潮式呼吸模型。呼吸生理学。106，209 - 221]。我们首先将这些方程扩展到多离散肺泡腔肺模型，然后扩展到具有体积、通气和灌注连续分布的肺模型。讨论了对多腔室模型输出参数的影响，并将结果与传统连续通气模型得出的结果进行了比较。使用几乎不溶性气体氩作为示踪气体，提出了一种肺泡不均匀性的经验指标，该指标使用每次呼吸的呼气末和混合呼气分压。该指标区分了通气量的窄单峰分布、通气量的宽单峰分布和通气量的双峰分布。通过蒙特卡罗模拟，该指标被证明对实际大小的实验误差具有稳定性。
