AA gradient adjustment

Q: A-a gradient should be ideally adjusted for? 

A) age 
B) gender 


Answer: A

The formula for A-a gradient is 

 A-a gradient = 2.5 + 0.21 x age in years 

Where: 0.21 is the room air - and should be substituted with the level of oxygen patient is breathing. 


#pulmonary


References: 

Sarkar M, Niranjan N, Banyal PK. Mechanisms of hypoxemia [published correction appears in Lung India. 2017 Mar-Apr;34(2):220]. Lung India. 2017;34(1):47–60. doi:10.4103/0970-2113.197116