Common acute asthma exam questions for medical finals, OSCEs and MRCP PACES

 

Question 1. Presentation of asthma

List four characteristic clinical features of asthma

  • Cough
  • Dyspnoea
  • Wheeze
  • Chest tightness

List the features that characterise a moderate asthma attack

  • Worsening symptoms
  • No features of acute severe asthma
  • PEFR >50% of best/predicted

List the features that characterise an acute severe asthma attack

  • Inability to complete sentences in a single breath
  • PEFR <50% of best/predicted
  • RR >/= 25
  • HR >/= 110

List the features that characterise a life-threatening asthma attack

  • Poor respiratory effort
  • Cyanosis
  • Silent chest
  • Hypotension
  • Arrhythmia
  • Exhaustion
  • Reduced conscious level
  • PEFR <33% of best/predicted
  • SpO2 <92%
  • PaO2 <8 kPa
  • Normal PaCO2 = 4.6-6.0 kPa

 

Question 2. Management of asthma

What is the initial treatment for acute asthma?

  • Sit upright.
  • Salbutamol 5 mg and ipratropium bromide 0.5 mg via oxygen-driven nebuliser

Should patients display an inadequate response to initial therapy, what further treatments can be given?

  • Repeat salbutamol 5 mg via oxygen-driven nebuliser if inadequate response and give prednisolone 40 mg orally (PO) or hydrocortisone 100 mg IV if unable to swallow
  • Consider ‘back-to-back’ salbutamol nebulisers or continuous salbutamol nebuliser 5-10 mg/h if inadequate response
  • Consider magnesium sulphate 1.2-2.0 g IV over 20 minutes in life-threatening or near-fatal asthma or in acute severe asthma with an inadequate response to initial therapy
  • Consider aminophylline 5 mg/kg IV loading dose over 20 minutes followed by 0.5 mg/kg/h IV maintenance dose in life-threatening or near-fatal asthma with an inadequate response to initial therapy

What features would concern you on an ABG in acute asthma

  • Low pH
  • PaCO2 >4.6 kPa
  • PaO2 <8 kPa

What are the indications for requesting a CXR in acute asthma?

  • Suspected pneumothorax or consolidation
  • Life-threatening asthma
  • Failure to respond to initial therapy
  • Requirement for ventilation

What criteria would mandate admission for acute asthma?

  • Life-threatening asthma
  • Near-fatal asthma
  • Acute severe asthma persisting despite initial therapy

 

Question 3. Discharging patients with asthma

What criteria must be achieved to consider discharge following acute asthma?

  • PEFR >75% of best/predicted 1 hour after initial therapy

What would you check before discharge?

  • Give prednisolone 40 mg once daily for five days
  • Check inhaler technique and ensure sufficient, in-date inhaled bronchodilator
  • Arrange follow up with GP in two days