Respiratory Failure

Question 0

Describe how ventilation/perfusion mismatch and diffusion impairment results in type 1 respiratory failure, and outline the important causes

Answer 0

Ineffective transfer of oxygen from alveoli –> blood

Causes - pulmonary embolism, pneumonia, consolidation, early stages of acute asthmas, pulmonary oedema, fibrosis

Question 1

Describe Type 1 and Type 2 respiratory failure

Answer 1

Type 1 - decreased oxygen, decreased/normal CO2 (reduced transfer of oxygen)
Type 2 - decreased oxygen, increased CO2 (ineffective respiratory effort)

Question 2

Describe how type 2 respiratory failure occurs, and outline some important causes

Answer 2

Ineffective respiratory effort

Causes - chest wall problems, trauma, scoliosis, COPD, asthma, respiratory depression, muscle weakness, emphysema

Question 3

Explain some of the symptoms of respiratory failure

Answer 3

Breathlessness
Type 1 - exercise intolerance, central cyanosis
Type 2 - CO2 retention, reduction of respiratory drive

Question 4

Explain why you should never give a patient with respiratory failure 100% high flow oxygen

Answer 4

Patient has persistent hypoxia
CSF [HCO3-] would’ve been reset by choroid plexus cells in medulla oblongata
If patient is given 100% oxygen, patient loses drive to breathe as they are used to a hypoxic state
Therefore –> 24% low rate oxygen

Question 5

Identify the steps in the oxygen transport pathway from air to tissues

Answer 5

Air –> airways –> alveolar gas –> alveolar membrane –> arterial blood –> regional arteries –> capillary blood –> tissues