respiratory failure

Question 1

types of respiratory failure

Answer 1

Type I Respiratory failure (Hypoxaemic respiratory failure)
Type II Respiratory failure (Hypercapnic respiratory failure)
can be acute or chronic

Question 2

Type I Respiratory failure (Hypoxaemic respiratory failure)

Answer 2

Low arterial oxygen (PaO2 < 60mmHg) AND normal or low arterial carbon dioxide
(PaCO2 < 45mmHg)

Question 3

Type II Respiratory failure (Hypercapnic respiratory failure)

Answer 3

Low arterial oxygen (PaO2 < 60mmHg) AND increased/high arterial carbon dioxide
(PaCO2 > 50 mmHg)

Question 4

Pathophysiology of Type I

respiratory failure

Answer 4

Numerous causes but broadly speaking
it is failure of oxygenation
1. Low inspired PO2
2. Alveolar Hypoventilation
3. Diffusion impairment
4. ventilation-perfusion mismatch
5. Shunt

Question 5

Low inspired PO2

Answer 5

low inspired oxygen concentration

Question 6

Alveolar Hypoventilation

Answer 6

inadequate alveolar ventilation

Question 7

Diffusion impairment

Answer 7

pulmonary capillary blood fails to reach equilibrium with alveolar gas

Question 8

ventilation-perfusion mismatching

Answer 8

blood areas from high V/Q to low V/Q areas

Question 9

left to right shunt

Answer 9

shunted blood fails to undergo gas exchages

Question 10

Pathophysiology of Type II

respiratory failure

Answer 10

Failure of the respiratory muscle
pump or ventilatory failure.
This has three components;
•Neural respiratory drive
•Respiratory muscle pump capacity
•Increase in respiratory load that
cannot be overcome

Question 11

causes of Respiratory failure type 1

Answer 11

• Asthma
• Pneumonia
• Shock
• Anatomical shunt (VSD)
• Pulmonary oedema
• Pulmonary embolism

Question 12

causes of Respiratory failure type 2

Answer 12

• Asthma
• COPD
• CF
• Drug Overdose
• Cystic fibrosis
• Sleep apnoea
• Chronic neuromuscular disorders
• Chest wall disorders
• Morbid obesity

Question 13

Signs of hypoxaemia

Answer 13

Peripheral
(cyanosis)
cerebral
( Headache, nausea, agitation,)
• Respiratory
(Dyspnoea)
• Cardiovascular
(Tachycardia, hypertension)

Question 14

Signs of hypercapnia

Answer 14

Cardiovascular
•( hypertension)
• Other
(Signs of hypoxemia)

Question 15

Investigations/diagnostic studies

Answer 15

Physical assessment
ABG
Chest X-ray
Pathology
FBC
Serum electrolytes
Blood cultures/sputum cultures
PFT (chronic respiratory failure)

Question 16

Management/treatment

Answer 16

Preserve oxygenation and ventilation
Direct treatment towards underlying cause
Respiratory support
• Oxygen therapy
• NIV (CPAP/BiPAP)
• Invasive ventilation
Mobilisation of secretions
• Hydration and humidification
• Chest physiotherapy
• Nasopharyngeal, oropharyngeal suctioning