Reinhart M E, Hughes J R, Kung M, Abraham W M, Ahmed T, Eyre P, Wanner A
Am Rev Respir Dis. 1979 Sep;120(3):533-40. doi: 10.1164/arrd.1979.120.3.533.
To test the hypothesis that the effect of nonuniform gas distribution on the uptake of inhaled soluble gases in the lung is minimized by rebreathing, we measured pulmonary blood flow by the thermodilution technique, and pulmonary capillary blood flow, combined pulmonary tissue and capillary blood volume, diffusing capacity of the lung for CO, and alveolar volume by a rebreathing technique in conscious sheep before and immediately after inhalation of a histamine aerosol (4% solution). We also measured pulmonary resistance, distribution of ventilation by multiple-breath N2 washout, and arterial blood gases to monitor airway responses. Histamine inhalation produced a mean pulmonary resistance increase to 621% of baseline accompanied by uneven distribution of ventilation and a decrease in arterial Po2. Despite these alterations in airway function, there were no concomitant changes in pulmonary capillary blood flow, combined pulmonary tissue and capillary blood volume, diffusing capacity of the lung for CO, alveolar volume, or the ratio of diffusing capacity for CO to alveolar volume. Mean pulmonary capillary blood flow and pulmonary blood flow did not differ from each other before and after histamine inhalation. We conclude that the rebreathing technique for noninvasive measurement of pulmonary hemodynamics is satisfactory in the presence of airflow obstruction.
为了验证通过重复呼吸可使肺部气体分布不均对吸入性可溶性气体摄取的影响降至最低这一假设，我们在清醒绵羊吸入组胺气雾剂（4%溶液）之前及之后立即，通过热稀释技术测量肺血流量，通过重复呼吸技术测量肺毛细血管血流量、肺组织与毛细血管血容量之和、肺对一氧化碳的弥散能力以及肺泡容积。我们还测量了肺阻力、通过多次呼吸氮气冲洗法测定的通气分布以及动脉血气，以监测气道反应。吸入组胺使肺阻力平均增加至基线的621%，同时伴有通气分布不均以及动脉血氧分压降低。尽管气道功能出现了这些改变，但肺毛细血管血流量、肺组织与毛细血管血容量之和、肺对一氧化碳的弥散能力、肺泡容积或一氧化碳弥散能力与肺泡容积之比均未随之发生变化。组胺吸入前后，平均肺毛细血管血流量与肺血流量并无差异。我们得出结论，在存在气流阻塞的情况下，用于无创测量肺血流动力学的重复呼吸技术是令人满意的。
