Flow Diagram Outlining the Diagnostic Approach to the Pt with Hypoxemia - Flowchart
Flow Diagram Outlining the Diagnostic Approach to the Pt with Hypoxemia - Flowchart
«Flowchart»

Is PaCO2 increased?

Is PaCO2 increased?

Is PaCO2 increased?

CO 2

Yes

Yes

Yes

No

No

No

Hypoventilation

Hypoventilation

Hypoventilation

Is PAO2 – PaO2 increased?

Is PAO2 – PaO2 increased?

Is PAO2 – PaO2 increased?

AO 2 O 2

Hypoventilation alone

Hypoventilation alone

Hypoventilation alone

Hypoventilation plus another mechanism

Hypoventilation plus another mechanism

Hypoventilation plus another mechanism


    ↓ Respiratory drive
    Neuromuscular disease

    ↓ Respiratory drive
    Neuromuscular disease

    ↓ Respiratory drive
    Neuromuscular disease

↓ Respiratory drive ↓
Neuromuscular disease

Hypoventilation{3}

Hypoventilation{3}

Hypoventilation{3}

Is PAO2 – PaO2 increased?

Is PAO2 – PaO2 increased?

Is PAO2 – PaO2 increased?

AO 2 O 2

Is low PO2 correctable with O2?

Is low PO2 correctable with O2?

Is low PO2 correctable with O2?

O 2 2

/ Mismatch

/ Mismatch

/ Mismatch

Shunt

Shunt

Shunt


    Airways disease (asthma, COPD)
    Interstitial lung disease
    Alveolar disease
    Pulmonary vascular disease

    Airways disease (asthma, COPD)
    Interstitial lung disease
    Alveolar disease
    Pulmonary vascular disease

    Airways disease (asthma, COPD)
    Interstitial lung disease
    Alveolar disease
    Pulmonary vascular disease

Airways disease (asthma, COPD)
Interstitial lung disease
Alveolar disease
Pulmonary vascular disease

    Alveolar collapse (atelectasis)
    Intraalveolar filling (pneumonia, pulmonary edema)
    Intracardiac shunt
    Vascular shunt within lungs

    Alveolar collapse (atelectasis)
    Intraalveolar filling (pneumonia, pulmonary edema)
    Intracardiac shunt
    Vascular shunt within lungs

    Alveolar collapse (atelectasis)
    Intraalveolar filling (pneumonia, pulmonary edema)
    Intracardiac shunt
    Vascular shunt within lungs

Alveolar collapse (atelectasis)
Intraalveolar filling (pneumonia, pulmonary edema)
Intracardiac shunt
Vascular shunt within lungs

↓Inspired PO2

↓Inspired PO2

↓Inspired PO2

↓ O 2

    High altitude
    ↓FlO2

    High altitude
    ↓FlO2

    High altitude
    ↓FlO2

High altitude
↓FlO2 ↓ lO 2

End

End

End

Yes

Yes

Yes

No

No

No

Yes

Yes

Yes

No

No

No

Yes

Yes

Yes

No

No

No