A simple staging system is used in Japan to evaluate a patient with idiopathic pulmonary fibrosis (IPF).
Parameters:
(1) PaO2 in mm Hg (torr) at rest on room air
(2) percutaneous oxygen saturation (SpO2) in percent at the end of a 6 minute walking test
|
PaO2
|
SpO2
|
Stage (Revised)
|
|
>= 80 mm Hg
|
>= 90%
|
I
|
|
>= 80 mm Hg
|
< 90%
|
II
|
|
70-79 mm Hg
|
>= 90%
|
II
|
|
70-79 mm Hg
|
< 90%
|
III
|
|
60-69 mm Hg
|
>= 90%
|
III
|
|
60-69 mm Hg
|
< 90%
|
IV
|
|
< 60 mm Hg
|
NA
|
IV
|
where:
• In the original staging system a PaO2 >= 80 mm Hg was Stage I.
|
Stage (revised)
|
5-Year Survival
|
|
I
|
62%
|
|
II
|
46%
|
|
III
|
31%
|
|
IV
|
20%
|
from Table I (Kondoh, 2017)
