Critical care: conditions

Question 1

What is the difference between type 1 and 2 respiratory failure?

Answer 1

Type 1 due to failure of oxygenation - Low O2 and Normal or Decreased CO2

Type 2 due to ventilatory failure - Low O2 and High CO2

Question 2

What are the key causes of type 1 respiratory failure?

Answer 2

1. V/Q mismatch (most common) - e..g pleural effusion, pneumonia, PE, pneumothorax, asthma
2. Reduced FIO2 - high altitude
3. Airway obstruction
4. R-2-L shunt due to heart defect (venous blood bypassing gas exchange)
5. Diffusion impairment - i.e. during levels of high CO2 such as exercise

Question 3

What are the signs of type 1 resp failure?

Answer 3

Signs of hypoxia

1. Increased WoB
2. Cyanosis
3. Dyspnoea
4. Restless, agitated, confused, altered LoC
5. Polycythaemia, pulmonary HTN and Cor Pulmonale

Also signs of respiratory distress, inability to complete sentences, tachypnoea

Question 4

What is the treatment of type 1 respiratory failure?

Answer 4

1. Correct oxygen levels by giving 35-60% oxygen (higher if required)
2. Treat cause using - Salbut, Abx, steroids, drain etc.
3. CPAP if hypoxaemia not corrected

Question 5

What are the benefits and cons of CPAP and when would you utilise it?

Answer 5

Pros - Improves functional residual volume and V/Q mis match and reduces atelectasis, WoB, risk of airway obstruction, fluid leak into lungs

Cons - can worsen pneumothoraces, cause hypotension and worsen facial fractures

Indications - pulmonary oedema, fluid overload, atelectasis, pneumonia

Question 6

What is the primary cause of type 1 respiratory failure?

Answer 6

V/Q mismatch due to lung pathology e.g. pneumonia, pulmonary oedema, PE, asthma, pneumothorax

Question 7

What is the pathophysiological process of type 2 resp failure?

Answer 7

Alveolar hypoventilation –> decreased Co2 clearance –> increased CO2 retention a/w hypoxaemia

Question 8

what is the main cause of type 2 respiratory failure

Answer 8

Chronic lung condition causing alveolar hypoventilation, damage to alveoli or increase resistance in airways
e.g. COPD, Asthma, pul fibrosis

Question 9

What are the signs of type 2 respiratory failure?

Answer 9

Signs of hypercapnia

• tachycardia, bounding pulse, peripheral vasodilation
• restless, tremor, CO2 flaps
• tachypnoea, cyanosis
• Headache, confused, drowsy, coma

Question 10

what is the treatment for type 2 respiratory failure?

Answer 10

1. Oxygenation 24% start then increase as required
2. Treat cause
3. BIPAP if CO2 not reducing

Question 11

What are the benefits and cons of BIPAP and when would you utilise it? How does it work?

Answer 11

Combination of EPAP and IPAP allows increased pressure for inspiratory ventilation

Benefits - Increase minute vol by increasing tidal vol

Cons - mask intolerance

Indiucations - hypercapnia state, COPD