Respiratory Failure

Question 1

What is respiratory failure?

Answer 1

Condition where respiratory system fails in one or both of its gas exchange functions: oxygenation and carbon dioxide elimination

Respiratory failure can be classified into two types based on gas exchange abnormalities.

Question 2

What characterizes Type 1 respiratory failure?

Answer 2

PaO2 <8kPa (normal/low PaCO2)

Type 1 is also known as hypoxemic respiratory failure.

Question 3

What characterizes Type 2 respiratory failure?

Answer 3

PaO2 <8kPa AND PaCO2 >6kPa

Type 2 is also known as hypercapnic respiratory failure.

Question 4

List some pulmonary causes of respiratory failure.

Answer 4

• COPD
• pneumonia
• pulmonary embolism
• acute respiratory distress syndrome
• lung cancer

These conditions primarily affect the lungs and gas exchange directly.

Question 5

List some extrapulmonary causes of respiratory failure.

Answer 5

• musculoskeletal disorders (e.g., myasthenia gravis)
• nervous system disorders (e.g., Guillain-Barre, ALS)
• sepsis
• drug overdose

Extrapulmonary causes affect the respiratory system indirectly.

Question 6

What are some risk factors for respiratory failure?

Answer 6

• smoking
• air pollution
• ageing
• immunocompromised

These factors can increase the likelihood of developing respiratory conditions leading to failure.

Question 7

What are the pathophysiological mechanisms in Type 1 respiratory failure?

Answer 7

• ventilation-perfusion mismatch
• ventilation-perfusion shunting

These mechanisms affect the ability of the lungs to oxygenate blood effectively.

Question 8

What are the pathophysiological mechanisms in Type 2 respiratory failure?

Answer 8

• decreased minute ventilation
• increased physiological dead space
• inadequate compensation

These mechanisms lead to a buildup of carbon dioxide in the bloodstream.

Question 9

What are some clinical features of respiratory failure?

Answer 9

• dyspnoea
• tachypnoea
• cough

These are common respiratory symptoms observed in patients with respiratory failure.

Question 10

What physical signs may indicate respiratory failure?

Answer 10

• cyanosis
• use of accessory muscles
• pursed-lip breathing

These signs can be indicative of respiratory distress and inadequate oxygenation.

Question 11

What systemic features may be observed in respiratory failure?

Answer 11

• confusion/altered consciousness
• peripheral oedema
• polycythaemia

These systemic features reflect the impact of respiratory failure on overall body function.

Question 12

What are some management options for respiratory failure?

Answer 12

• oxygen therapy
• non-invasive ventilation
• invasive mechanical ventilation
• extracorporeal membrane oxygenation

These interventions aim to restore adequate gas exchange and support the patient’s breathing.