te Nijenhuis F C, Jansen J R, Versprille A
Department of Pulmonary Diseases, Erasmus University Rotterdam, The Netherlands.
Clin Physiol. 1997 May;17(3):225-36. doi: 10.1111/j.1365-2281.1997.tb00002.x.
We studied the effect of increasing alveolar volume on pulmonary carbon monoxide transfer (DLCO) and its components, i.e. membrane diffusing capacity (DM) and capillary blood volume (Qc), during mechanical ventilation in eight anaesthetized and paralysed healthy pigs (mean weight 11.2 kg). We used an inspiratory pause procedure for simulation of the single-breath technique, and inflated 15, 20, 25 and 30 ml kg-1 in random order. DM and Qc were derived using the Roughton-Forster equation. Per litre BTPS increase in effective VA, DLCO (inspiratory oxygen fraction 0.30) decreased on average by 11.8 mumol s-1 kPa-1, DM slightly increased by 2.7 mumol s-1 kPa-1 and Qc decreased by 241 ml. The increase in DM was much smaller than might be expected from the increase in VA, which we ascribe to a loss of the alveolar capillary membrane for gas transfer because of the concomitant decrease in Qc. The decrease in Qc may be explained by a squeezing effect of the intrapulmonary pressure rise on the alveolar wall and by stretching of lung tissue.
我们研究了在八只麻醉并瘫痪的健康猪（平均体重11.2千克）机械通气期间，增加肺泡容积对肺一氧化碳转运（DLCO）及其组成部分，即膜扩散容量（DM）和毛细血管血容量（Qc）的影响。我们采用吸气暂停程序模拟单次呼吸技术，并以随机顺序分别充气15、20、25和30毫升/千克。DM和Qc通过Roughton-Forster方程得出。每升BTPS有效VA增加时，DLCO（吸入氧分数为0.30）平均降低11.8微摩尔·秒⁻¹·千帕⁻¹，DM略有增加，为2.7微摩尔·秒⁻¹·千帕⁻¹，Qc降低241毫升。DM的增加远小于VA增加所预期的值，我们将其归因于伴随Qc降低导致用于气体交换的肺泡毛细血管膜损失。Qc的降低可能是由于肺内压力升高对肺泡壁的挤压作用以及肺组织的拉伸所致。
