Asthma has a prevalence of 5.8% in the UK and is responsible for 1500 deaths annually.

  • Features that increase the probability of asthma: 
    • Wheeze, breathlessness and cough, particularly if 
      • Worse at night/early morning
      • Occur in response to exercise, allergens, cold air, aspirin or beta blockers 
    • Family or personal history of atopy 
    • Widespread wheeze on auscultation 
    • Otherwise unexplained low FEV1 or PEF 
    • Otherwise unexplained peripheral blood eosinophilia
  • Features that lower the probability of asthma:
    • Prominent dizziness/light-headedness
    • Chronic productive cough in absence of wheeze or breathlessness 
    • Voice disturbance 
    • Significant smoking history


  • If high probability of asthma – trial of treatment 
  • If intermediate probability – perform spirometry
    • FEV1/FVC <0.7 – trial of treatment 
    • FEV1/FVC >0.7 - consider referral to specialist 
  • Low probability consider referral to specialist 

An increase of PEF >15% from baseline or increase of FEV1 > 400mls following a trial of treatment supports the diagnosis of asthma 


Chronic asthma
  • Step 1: 
    • Inhaled short-acting beta 1 agonist PRN 
  • Step 2: 
    • Step 1 + inhaled steroid 
  • Step 3: 
    • Step 2 + long-acting beta 2 agonist 
    • If control still inadequate consider 
      • Stopping long-acting beta 2 agonist if no response
      • Increasing inhaled steroid 
      • Trial of leukotriene receptor antagonist or SR theophylline
  • Step 4: 
    • Step 3 + Further increase of inhaled steroid 
    • Addition of leukotriene receptor antagonist or SR theophylline or beta 2 agonist tablet
  • Step 5: 
    • Step 4 + oral steroid 

Acute asthma attacks 

  • Assement of severity of asthma 
    • Acute severe
      • Any one of
        • PEF 33-50% best or predicted 
        • Respiration rate ≥ 25/minute 
        • Heart rate ≥ 110/minute 
        • Inability to complete sentences in one breath 
    • Life-threatening
      • Any one of 
        • PEF <33% best or predicted
        • SpO2 < 92%
        • PaO2 < 8 kPa 
        • Normal PaCO2
        • Silent chest 
        • Cyanosis
        • Poor respiratory effort 
        • Arrhythmia 
        • Exhaustion, altered conscious level
    • Near fatal 
      • Raised PaCO2 and/or requiring mechanical ventilation with raised inflation pressures 

  • Treatment of acute severe asthma 
    • Oxygen 
    • Nebulised salbutamol 
    • Nebulised ipratropium bromide 
    • Prednisolone 40-50mg od – continue for at least 5 days or until recovery 
    • Consider single dose of IV magnesium sulphate 

  • Admit patients: 
    • With any feature of life threatening or near fatal attack 
    • Any feature of severe attack persisting after initial treatment
    • Patients whose peak flow is >75% predicted or best one hour after initial treatment may be discharged from ED unless there are other indications for admission 

  • If patient is admitted, prior to discharge patient should: 
    • Have been on discharge medication for 12-24 hours
    • Have PEF >75% predicted or best and PEF diurnal variability <25% 
    • GP follow up arranged within 2 working days 
    • Respiratory clinic follow up within 4 weeks 

Small print gem: female gender is a risk factor for persistence of asthma from childhood to adulthood.


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