A-a Oxygen Gradient
Pa
O
2
(partial pressure of arterial O
2
):
mmHg
Pa
CO
2
(partial pressure of arterial CO
2
):
mmHg
Atmospheric Pressure:
atmospheric pressure in mmHg
altitude in feet
altitude in meters
Inspired Oxygen Concentration (Fi
O
2
):
Room Air (21 percent)
Other:
known oxygen concentration (percent)
oxygen delivered (L/min)
A-a Gradient =
mmHg
A-a (O
2
) = (Fi
O
2
%/100) * (P
atm
- 47 mmHg) - (Pa
CO
2
/0.8) - Pa
O
2
(all units mmHg)
Created by:
Charles Hu
,
Ron Kneusel
&
Gary Barnas M.D.
Created: Saturday, January 15, 2000
Last Modified: