Mechanisms of gas exchange abnormality in patients with chronic obliterative pulmonary vascular disease.
AUTOR(ES)
Dantzker, D R
RESUMO
We have examined the mechanisms of abnormal gas exchange in seven patients with chronic obliteration of the pulmonary vascular bed secondary to recurrent pulmonary emboli or idiopathic pulmonary hypertension. All of the patients had a widened alveolar-arterial oxygen gradient and four were significantly hypoxemic with arterial partial presssures of oxygen less than 80 torr. Using the technique of multiple inert gas elimination, we found that ventilation-perfusion (VA/Q) relationships were only minimally abnormal with a mean of 10% (range, 2--19%) of cardiac output perfusing abnormal units. These units consisted of shunt and units with VA/Q ratios less than 0.1. In addition, the dead space was found to be normal in each patient. There was no evidence for diffusion impairment, and the widened alveolar-arterial oxygen gradient was completely explained by VA/ inequality. Significant hypoxemia occurred only when VA/Q inequality was combined with a low mixed venous oxygen content.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=372215Documentos Relacionados
- Contribution of multiple inert gas elimination technique to pulmonary medicine--4. Gas exchange abnormalities in pulmonary vascular and cardiac disease.
- Exercise in patients with chronic obstructive pulmonary disease.
- Pulmonary vascular structure and function in chronic obstructive pulmonary disease.
- Mechanisms underlying CO2 retention during flow-resistive loading in patients with chronic obstructive pulmonary disease.
- Ventilation and gas exchange during sleep in patients with interstitial lung disease.