Causes of hypoxemia

PaO₂

PaCO₂

P(A-a)O₂ gradient

Alveolarventilation

Response to FiO₂ of 1

Reduction of FiO₂

↓

↓

=

↑

Yes

Hypoventilación

↓

↑

=

↓

Yes

V/Q mismatch

↓

↑↓

↑

=↑

Yes

Shunting

↓

↓

↑

↑

No

Difussion alteration

↓

↓

↑

↑

Yes