Asthma

Question 1

What are the risk factors for asthma development?

Answer 1

• Genetics
• Atopy (elevated IgE)
• Airway hyper-responsiveness
• Female sex

Question 2

Outline the pathophysiology of asthma

Answer 2

• Acute
  
  • Eosinophil/mast cell mediator release
  • Bronchoconstriction/oedema/mucus release
• Chronic
  
  • Smooth muscle/goblet cell hyperplasia, BM thickening, airway hyperresponsiveness

Question 3

What symptoms on history is someone with asthma likely to present with?

Answer 3

• SOB - especially at morning, night, exercise
• FHx (and atopy)
• Wheeze
• Chest tightness
• Dry cough
• Triggers
• Reversible episodes

Question 4

What signs on examination is someone in an acute asthma attack likely to exhibit?

Answer 4

• Anxiety
• Tachypnoea
• Cyanosis
• Accessory muscle activation
• Substernal intercostal retraction
• Pursed-lip breathing (back-pressure against airways splints them open)
• Prolonged expiration with wheeze (narrow lumen)
• Reduced breath sounds (hyperinflation)
• Reduced heart sounds (hyperinflation)
• Pulsus paradoxus (higher intrathoracic pressure on inspiration)

Question 5

What investigations are needed to make a diagnosis of asthma?

Answer 5

• Peak flow - >20% variation day-to-day
• Spirometry - improvement with bronchodilator
• Bronchoprovocation (methylcholine, mannitol)

Question 6

What are the principles of managment of a patient with asthma?

Answer 6

• Control symptoms and prevent exacerbations
  
  • SABA +/- ICS, LABA
• Acutely - oxygen, bronchodilators, oral CS, IV Mg