3+ Respiratory Failure

Question 1

What is respiratory failure?

Answer 1

Failure of gas exchange resulting in hypoxia

Question 2

What are the two types of respiratory failure?

Answer 2

Type 1: hypoxia with normal or low pCo2

Type 2: hypoxia with hypercapnia

Question 3

What is the aetiology of Type 1 respiratory failure:

Answer 3

1. V/Q mismatch:
   - Decreased ventilation: pneumonia, pulmonary oedema, CF
   - Decreased perfusion: shock
2. R/L cardiac shunts

Question 4

What is the aetiology of Type 2 respiratory failure?

Answer 4

Occurs when alveolar ventilation is insufficient to excrete the carbon dioxide being produced either because there’s reduced ventilatory effort or an inability to overcome increased resistance to ventilation

1. Pulmonary disease: asthma, COPD, pulmonary fibrosis, OSA
2. Reduced respiratory drive: sedatives, CNS tumour
3. Neuromuscular disease: GBS, myasthenia gravis, cervical cord lesion

Question 5

What is the clinical presentation of hypoxia?

Answer 5

Dyspnoea
Restlessness
Confusion
Central cyanosis
Agitation

Question 6

What is the clinical presentation of hypercapnia?

Answer 6

Headache
Peripheral vasodilation
Tachycardia
Bounding pulse
Tremor/flap
Papilledema
Pul HTN
Cor pulmonale

Question 7

What are some complications of hypercapnia?

Answer 7

Cardiac arrest
Arrhythmias
Respiratory arrest
Seizures
Coma

Question 8

How do you treat type 2 resp failure?

Answer 8

Treat underlying cause
Controlled O2 therapy (24%) (often it’s driven by hypoxia)
Recheck ABG after 20 min: if pCO2 high consider CPAP/BIPAP
If CO2 steady or decreased then you can increase O2