Lung volumes, dead space and alveolar ventilation
The static lung volumes and how they're measured, lung volume patterns in obstructive, restrictive and extraparenchymal disease, anatomical and physiological dead space (Bohr), and the alveolar ventilation equation that links breathing pattern to PaCO2.
Tier 2Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Tidal volume (about 500 mL), inspiratory and expiratory reserve volumes and vital capacity are measured by spirometry. Residual volume, FRC and TLC need body plethysmography or gas dilution.
- Restriction means a low TLC. Obstruction means a low FEV1/FVC.
- Only ventilation that reaches perfused alveoli clears CO2. Alveolar ventilation = (VT - VD) × RR.
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Sources
- West's Respiratory Physiology: The Essentials (11th ed.)Wolters Kluwer (West and Luks, 2021), 2021
- ERS/ATS technical standard on interpretive strategies for routine lung function testsEuropean Respiratory Journal (Stanojevic et al.), 2022
- Standardization of Spirometry 2019 Update: An Official ATS/ERS Technical StatementAmerican Journal of Respiratory and Critical Care Medicine (Graham et al.), 2019
- A Race-neutral Approach to the Interpretation of Lung Function MeasurementsAmerican Journal of Respiratory and Critical Care Medicine (Bowerman et al.), 2023
- Race and Ethnicity in Pulmonary Function Test Interpretation: An Official American Thoracic Society StatementAmerican Journal of Respiratory and Critical Care Medicine (Bhakta et al.), 2023
- Examination of the carbon monoxide diffusing capacity (DLCO) in relation to its KCO and VA componentsAmerican Journal of Respiratory and Critical Care Medicine (Hughes JM and Pride NB, 2012;186:132-9), 2012
- Volumetric capnography: lessons from the past and current clinical applicationsCritical Care (Verscheure S et al., 2016;20:184), 2016
- Last updated
- 14 November 2026
What changed
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