This video is the 4th in a series of 4 videos on the alveolar air equation and its applications. The other 3 can be found on our page.
This introduces the concept of the Aa gradient and how it can be used clinically.

Ref:
1)John West Respiratory Physiology, The essentials
2)Egan's Fundamentals of Respiratory Care (9ed), Wilkins, Stoller and Kacmarek
3) Sibberson's Practical Math For Respiratory Care