RELATIONSHIPS AMONG VENTILATION-PERFUSION DISTRIBUTION, MULTIPLE INERT GAS METHODOLOGY AND METABOLIC BLOOD-GAS TENSIONS

Ventilation-perfusion relationships and gas exchange.

The most common cause of hypoxemia at sea level is mismatched ventilation and per­ fusion. Common clinical problems such as pneumonia, pulmonary embolism, obstruc­ tive lung disease and many other diseases produce regional hypoventilation as com­ pared to perfusion, resulting in incompletely oxygenated blood leaving the pulmonary capillary in hypoventilated regions and re­ turning to the left h...

Understanding pulmonary gas exchange: ventilation-perfusion relationships.

This essay looks at the historical significance of four APS classic papers that are freely available online: Fenn WO, Rahn H, and OTIS AB. A theoretical study of the composition of the alveolar air at altitude. Am J Physiol 146: 637-653. 1946 (http://ajplegacy.physiology.org/cgi/reprint/146/5/637). Rahn H. A concept of mean alveolar air and the ventilation-bloodflow relationships during pulmona...

Gas exchange and ventilation-perfusion relationships in the lung.

This review provides an overview of the relationship between ventilation/perfusion ratios and gas exchange in the lung, emphasising basic concepts and relating them to clinical scenarios. For each gas exchanging unit, the alveolar and effluent blood partial pressures of oxygen and carbon dioxide (PO2 and PCO2) are determined by the ratio of alveolar ventilation to blood flow (V'A/Q') for each u...

Multiple breath inert gas washout as a measure of ventilation distribution in children with cystic fibrosis.

BACKGROUND Multiple breath inert gas washout (MBW) has been suggested as a tool for detecting early cystic fibrosis (CF) lung disease. A study was undertaken to compare the relative sensitivity of MBW and spirometry for detecting abnormal lung function in school age children with CF and to compare MBW results obtained from healthy children in the UK with those recently reported from Sweden. M...

Agonal physiology and blood gas tensions.