Related Experiment Video
Updated: May 22, 2026

Dual Test Gas Pulmonary Diffusing Capacity Measurement During Exercise in Humans Using the Single-Breath Method
Published on: February 2, 2024
[Diagnostic importance of the alveolar-arterial oxygen gradient]
Marije A E Weinans1, Amanda M Drost-de Klerck, Jan C ter Maaten
1Universitair Medisch Centrum Groningen, afd. Spoedeisende Hulp, Groningen. marijeweinans@hotmail.com
Background:
The alveolar-arterial (A-a) oxygen gradient is the difference between the partial pressure of oxygen in the alveoli and the partial pressure of arterial oxygen and can be elevated in the case of pulmonary disease.
Case Description:
We describe a 41-year-old patient with pneumonia who presented with abdominal pain, in whom calculation of the A-a gradient could have led to earlier diagnosis.
Conclusion:
The A-a oxygen gradient is mainly of diagnostic importance and the presented nomogram allows easy and quick interpretation. This might lead to a more frequent use of the A-a oxygen gradient in the future.
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07:09Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise
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08:23Characterization of Sickling During Controlled Automated Deoxygenation with Oxygen Gradient Ektacytometry
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