Correction for Mechanical Dead Space in the Calculation of Physiological Dead Space
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چکیده
منابع مشابه
Correction for mechanical dead space in the calculation of physiological dead space.
When physiological dead space (Vd(p)) is calculated for a patient who has alveolar dead space, e.g., after pulmonary vascular occlusion, less than the full volume of attached mechanical dead space (Vd(m)) appears in the measured dead space (Vd(n)). Under these conditions the traditional subtraction of Vd(m) from Vd(n) leads to underestimation of Vd(p) and can give a falsely small ratio of Vd(p)...
متن کاملPrediction of the physiological dead-space in resting normal subjects.
1. Two-hundred and forty duplicate estimations of physiological dead-space volume ( VD) were made in forty-eight healthy subjects (twenty-four men and twenty-four women) aged from 20 to 74 years, to assess the predictive accuracy of various standards. 2. The V,/ VT (physiological dead-space volume/tidal volume) ratio standard was least precise, but could be improved by allowing for sex and age....
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CONSIDERABLE UNCERTAINTY existed regarding the magnitude of pulmonary dead space in the immediate post-World War II era. The dead space concept was originated by Bohr (2), who viewed total ventilation as composed of two distinct, but homogeneous, components—alveolar ventilation that participated fully in gas exchange and dead space ventilation in which no respiratory exchange occurred. With kno...
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BACKGROUND Respiratory dead-space is often increased in lung disease. This study evaluates the effects of increased alveolar dead-space (Vd(alv)), pulmonary shunt, and abnormal ventilation perfusion ratio (/) distributions on dead-space and alveolar partial pressure of carbon dioxide (Pa(co(2))) calculated by various methods, assesses a recently published non-invasive method (Koulouris method) ...
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An elevated physiological dead space, calculated from measurements of arterial CO2 and mixed expired CO2, has proven to be a useful clinical marker of prognosis both for patients with acute respiratory distress syndrome and for patients with severe heart failure. Although a frequently cited explanation for an elevated dead space measurement has been the development of alveolar regions receiving...
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ژورنال
عنوان ژورنال: Journal of Clinical Investigation
سال: 1972
ISSN: 0021-9738
DOI: 10.1172/jci107097