MacIntyre N R, Leatherman N, Deitz J L, Wagoner R, Friedman M
Respir Physiol. 1986 Feb;63(2):201-12. doi: 10.1016/0034-5687(86)90114-3.
In order to obtain a better understanding of intrapulmonary gas mixing and alveolar-capillary gas transport during high frequency oscillatory ventilation (HFO), we measured insoluble gas (He) equilibration, and soluble gas (CO, C2H2) uptake in the lungs of ten anesthetized dogs during closed system HFO (i.e. no fresh gas bias flow). These gases were introduced as a bolus into the lumen of an endotracheal tube and their concentrations were subsequently measured for 20-25 sec from a catheter in the distal end of this tube. Analysis of He concentrations over time was performed using a two compartment series model to calculate a value for effective ventilation (Veff). This Veff was found to range from 0.83 to 23.8 L/min and was directly related to oscillator output (f X VT product, r = 0.77). Analysis of CO and C2H2 concentrations during HFO using a similar two-compartment model having alveolar capillary gas transport in series with Veff allowed for the calculation of pulmonary capillary blood flow (QHFO) and lung diffusing capacity (DHFO). These values for QHFO were found to be not significantly different from simultaneous thermodilution determinations of cardiac output and these values for DHFO were found to be not significantly different from single breath or rebreathing determinations of CO diffusing capacity. Moreover, QHFO and DHFO did not vary with Veff. We conclude that this two compartment in series model is a reasonable way to characterize insoluble and soluble gas behavior during HFO, that Veff is related to oscillator output, and that QHFO and DHFO are not affected by HFO over the range of Veff studied.
为了更好地理解高频振荡通气（HFO）期间肺内气体混合及肺泡-毛细血管气体转运情况，我们在10只麻醉犬的肺脏中测量了在闭式系统HFO（即无新鲜气体偏流）期间不溶性气体（氦气）的平衡以及可溶性气体（一氧化碳、乙炔）的摄取。这些气体以团注形式注入气管导管管腔，随后从该导管远端的一根导管中测量20 - 25秒内它们的浓度。利用双室串联模型对氦气浓度随时间变化进行分析，以计算有效通气量（Veff）的值。发现该Veff范围为0.83至23.8升/分钟，且与振荡器输出（频率×潮气量乘积，r = 0.77）直接相关。在HFO期间，使用一个类似的双室模型（其中肺泡毛细血管气体转运与Veff串联）对一氧化碳和乙炔浓度进行分析，从而能够计算肺毛细血管血流量（QHFO）和肺扩散容量（DHFO）。发现这些QHFO值与同时通过热稀释法测定的心输出量无显著差异，且这些DHFO值与通过单次呼吸或重复呼吸法测定的一氧化碳扩散容量无显著差异。此外，QHFO和DHFO不随Veff变化。我们得出结论，这种双室串联模型是表征HFO期间不溶性和可溶性气体行为的合理方法，Veff与振荡器输出相关，并且在所研究的Veff范围内，QHFO和DHFO不受HFO影响。
