Respiratory Failure

Question 1

Respiratory failure?

Answer 1

Failure of ventilation and/or gaseous exchange (hypoxemia & hypercapnia)

Question 2

What are the causes of respiratory failure?

Answer 2

• Hypoxemic Respiratory Failure (COPD; Restrictive lung disease; severe pneumonia; atelectasis)
• Hypercapnia/Hypoxemic Respiratory Failure
  1. Upper airway obstruction (infection; laryngospasm; tumours)
  2. Weakness or paralysis of respiratory muscles (brain injury; drug overdose; Gillian-barre syndrome; muscular dystrophy; spinal cord injury)
  3. Chest wall injury
• Impaired diffusion (pulmonary Edema; ARDS)

Question 3

Manifestations of respiratory failure?

Answer 3

• depends on the cause
• hypoxemia (PaO2 < 60 mmHg)
• Hypercapnia (PaCO2 >45 mmHg)
• Respiratory acidosis

Question 4

What is the normal partial pressure of oxygen?

Answer 4

80-100 mmHg

Question 5

What is the normal partial pressure of CO2?

Answer 5

35-45 mmHg

Question 6

Respiratory acidosis?

Answer 6

Build up of CO2 converted into carbonic acid

Question 7

Treatment of respiratory failure?

Answer 7

Treat the underlying cause
Restore gas exchange via:
- O2 if gas exchange is not totally impaired to reverse hypoxemia
- mechanical ventilation
- bronchodilators (may help if failure was d/t COPD)
- Abx (if failure is d/t infection)