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