CONTINUOUS DISTRIBUTIONS OF VENTILATION-PERFUSION RATIOS IN NORMAL SUBJECTS BREATHING AIR AND 100 PERCENT O2
CONTINUOUS DISTRIBUTIONS OF VENTILATION-PERFUSION RATIOS IN NORMAL SUBJECTS BREATHING AIR AND 100 PERCENT O2
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DOI：
10.1172/jci107750
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发表时间：
1974-01-01
影响因子：
15.9
通讯作者：
WEST, JB
中科院分区：
文献类型：
--
作者：
WAGNER, PD;LARAVUSO, RB;WEST, JB
本文提出了一种基于六种不同溶解度气体稳态消除的通气-灌注比（V今A/Q今）分布的连续测量方法。该方法适用于12名正常受试者，年龄21-60岁。在九个，分布进行了比较呼吸空气和100%的氧气，而在其余三个，姿势变化的影响进行了检查。在4名年轻的半卧位受试者（年龄21-24岁）中，血流量和通气量相对于V ~ A/Q ~的分布几乎呈对数正态分布，离散度很小（平均对数标准差分别为0.43和0.35）。95.5%的血流量和通气量的范围为V ~ A/Q = 0.3-2.1，无肺内分流（V ~ A/Q = 0）。在呼吸氧气时，其中三名受试者出现分流，平均值为心输出量的0.5%。5名年龄较大的受试者（年龄39-60岁）具有更宽的分布（平均对数标准差，0.76和0.44），其中3名受试者的V ~ A/Q比在0.01-0.1范围内。至于年轻受试者，没有分流呼吸空气，但所有5名受试者都出现了分流呼吸氧气（平均值3.2%），其中1名受试者的值为10.7%。姿势变化通常是重力已知影响的预期变化，受试者直立时比仰卧时对高VA/Q区域的通气更多。测量的分流，而呼吸氧气，玻尔CO2死腔，肺泡动脉氧差都与观察到的分布一致。由于该方法只涉及一个短的注入溶解的惰性气体，动脉血和呼出气体的采样，并测量心输出量和每分钟通气量，我们得出结论，它是非常适合于调查的人肺气体交换。
A new method has been developed for measuring virtually continuous distributions of ventilation-perfusion ratios (V̇A/Q̇) based on the steadystate elimination of six gases of different solubilities. The method is applied here to 12 normal subjects, aged 21—60. In nine, the distributions were compared breathing air and 100% oxygen, while in the remaining three, effects of changes in posture were examined. In four young semirecumbent subjects (ages 21—24) the distributions of blood flow and ventilation with respect to V̇A/Q̇ were virtually log-normal with little dispersion (mean log standard deviations 0.43 and 0.35, respectively). The 95.5% range of both blood flow and ventilation was from V̇A/Q̇ ratios of 0.3—2.1, and there was no intrapulmonary shunt (V̇A/Q̇ of 0). On breathing oxygen, a shunt developed in three of these subjects, the mean value being 0.5% of the cardiac output. The five older subjects (ages 39—60) had broader distributions (mean log standard deviations, 0.76 and 0.44) containing areas with V̇A/Q ratios in the range 0.01—0.1 in three subjects. As for the young subjects, there was no shunt breathing air, but all five developed a shunt breathing oxygen (mean value 3.2%), and in one the value was 10.7%. Postural changes were generally those expected from the known effects of gravity, with more ventilation to high VA/Q areas when the subjects were erect than supine. Measurements of the shunt while breathing oxygen, the Bohr CO2dead space, and the alveolar-arterial oxygen difference were all consistent with the observed distributions. Since the method involves only a short infusion of dissolved inert gases, sampling of arterial blood and expired gas, and measurement of cardiac output and minute ventilation, we conclude that it is well suited to the investigation of pulmonary gas exchange in man.