ACUTE RESPIRATORY FAILURE

ACUTE RESPIRATORY FAILURE

Prof. Dr.
ABDUL HAMEED AL QASEER

Pathophysiology

• Decreased inspired partial pressure of oxygen
(PIO2) e.g. high altitude, reduced O2 mixture.
2. Hypoventilation
3. Ventilation perfusion mismatch ( V/Q).
• Shunting of blood from pul. to systemic circulation
• Abnormal diffusion of O2 from the alveoli into the capillary blood.

Acute Respiratory Failure

Classification:
Hypoxemic respiratory failure (Failure of oxygenation)
Hypercapnic respiratory failure (Failure of ventilation)



Hypoxemic Respiratory FailureEtiology and Pathophysiology

Causes:

Ventilation-perfusion (V/Q) mismatch
Shunt
Diffusion limitation
Alveolar hypoventilation

Fig. 66-4

Range of V/Q Relationships

Diffusion Limitation

Fig. 66-5

Causes of Type I ARF

Causes of Type II ARF

Clinical features of Hypoxemia & Hypercapnia

ACUTE SEVERE ASTHMA

ACUTE RESPIRATORY DISTRESS SYNDROME