منابع مشابه
Dead space: simplicity to complexity.
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...
متن کاملEffects of alveolar dead-space, shunt and V/Q distribution on respiratory dead-space measurements.
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) ...
متن کاملCorrection 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 کاملNasal high flow reduces dead space
Recent studies show that nasal high flow (NHF) therapy can support ventilation in patients with acute or chronic respiratory disorders. Clearance of dead space has been suggested as being the key mechanism of respiratory support with NHF therapy. The hypothesis of this study was that NHF in a dose-dependent manner can clear dead space of the upper airways from expired air and decrease rebreathi...
متن کاملDead space: the physiology of wasted ventilation.
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: Anaesthesia
سال: 1994
ISSN: 0003-2409,1365-2044
DOI: 10.1111/j.1365-2044.1994.tb04338.x