|Acute Severe Asthma
|Exacerbation of COPD
|Cardiogenic Pulmonary Oedema
|Respiratory (Chest) infections Pneumonia
- Asthma is a chronic respiratory illness with acute exacerbations with expiratory wheeze and reversible airways obstruction.
- Reversibility is key. Can be established by history, examination, PEFR records and spirometry
- Asthma is increasing worldwide and each year in the UK 1000-2000 people die of Asthma.
- Commoner in those with hay fever, urticaria and eczema and raised IgE and eosinophils - Allergic asthma.
- It is this rise in 'allergy' that may account for the overall rise in asthma incidence
- Excess of Th2 > Th1 in nasal and bronchial mucosa.
- Th2 lymphocytes secrete cytokines, inducing the production of IgE and cause maturation and recruitment of mast cells and eosinophils.
- Chronic inflammatory condition
- Thickening of the lamina reticularis. Eosinophilia seen in bronchial biopsies.
- Curschmann's spirals containing eosinophils and Charcot-Leyden granules suggest steroid responsiveness
- Cigarette smoke, Cold air and Irritant gases as well as Perfume and Deodorants
- House dust mite allergen, Aspergillus spores, Viral infections, Exercise and Emotional stresses
- Drugs - NSAIDs, Aspirin (associated with Nasal polyps), Beta-blockers. Tartrazine ( a colourant), Other chemicals - see occupational asthma
- Types of response to precipitant: Early bronchospasm post-exposure to precipitant. Delayed bronchospasm is seen in 1/3rd even up to 10 hours after initial exposure
- Intrinsic: Non atopic, Do not have evidence of raised IgE, Older patients with late onset asthma.
- Extrinsic: Atopic, Allergic asthma is commoner in children and young adults, Elevated IgE
- Expiratory dyspnoea and wheeze
- Chest tightness and cough (Cough often at night)
- Reduced chest expansion
Diagnosis:Clinical history compatible with asthma and
- Improved FEV by at least 12% (200 ml) after Salbutamol/trial of steroids. A 15% improvement is stronger evidence.
- More than 20% diurnal variation on = 3 days in a week for 2 weeks on PEF diary
- FEV1 = 15% decrease after 6 mins of exercise
- Bloods: FBC, U&E. CRP/ESR normal - usually normal unless infective component.
- Elevated Eosinophils
- Elevated IgE
- Elevated FENO
- CXR will in most cases be normal. However
- Lobar collapse with mucus plugging
- Infiltrates : aspergillus
- Spirometry: Measure FVC FEV1. FEV1/FVC ratio < 70% (or below the lower limit of normal if this value is available) is a positive test for obstructive airway disease
- PEFR shows variability > 20% with time and treatment. Predicted PEFR and diary of PEFR readings can show variability.
- An improved FEV1.0 by > 15% after 2 weeks of Prednisolone 30 mg od confirms the diagnosis.
- Fractional exhaled nitric oxide shows airway inflammation > 40 ppb in adults or 35 in children/young adults
- Bronchodilator reversibility (BDR) test (BDR) test: Increase FEV1 > 12% or more and increase in volume of 200 ml is positive
- Skin prick testing may be used to identify possible allergens to avoid. Aspergillus antibodies if eosinophilia or CXR shadowing
- Short acting beta agonist (SABA)
- Salbutamol metered dose "blue" inhaler used PRN as reliever therapy.
- Terbutaline inhaler used PRN as reliever therapy.
- Salbutamol nebuliser used in severe disease acute severe asthma.
- Long acting beta agonist (LABA) : Salmeterol.
- Anticholinergics: Ipratropium blocks muscarinic receptors.
- Inhaled corticosteroids (IHC):
- Low dose: Budesonide 200-400 mcg/day or equivalent
- Moderate dose: Budesonide 400-800 mcg/ay or equivalent
- High dose Budesonide 800-2000 mcg/day or equivalent
- Oral or IV Corticosteroids
- Prednisolone 30 mg short course for acute severe asthma.
- Hydrocortisone is used IV for acute severe asthma
- Steroid sparing agents
- IV Immunoglobulin
- Anti IgE monoclonal antibody Omalizumab
- Etanercept, Infliximab, Lebrkizumab
- Mast cell stabiliser: Sodium cromoglycate - inhibits. Cysteinyl Leukotriene receptor antagonist LT1 and LT2 receptors. Some are responsive. Give a trial.
- Phosphodiesterase inhibitor. Aminophylline
- Biologicals: Omalizumab - monoclonal ab binds to free IgE.
- Antibiotics: if evidence of infection.
- Steroid sparing agents: Cyclosporin, Methotrexate
- Magnesium: Used in acute severe asthma
Standard escalation process
|Step||Description||Details of management
|Step 1|| Mild intermittent Asthma || Short acting beta agonist as required such as a Salbutamol [US Albuterol] inhaler. Teach inhaler technique.
|Step 2|| Regular preventer medication|| Add Inhaled corticosteroid 200-800 mcg/day - start at 400 mcg/day eg Beclametasone, Budesonide, Fluticasone. Advise to rinse mouth after to avoid oral candidal infection or hoarseness.
|Step 3|| Add on therapy || Long acting beta2-agonist (LABA) e.g. Salmeterol and/or Increase inhaled steroid to 800 mcg/day if still not controlled. No response to LABA then stop it, continue steroid and consider SR Theophylline or Leukotriene receptor antagonist (Montelukast, Zafirlukast).
|Step 4|| Persistent poor control || Increase inhaled steroid dose to 2000 mcg/day - Add Leukotriene receptor antagonist/ Oral beta2 agonist tablet/SR Theophylline
|Step 5|| Continuous or frequent oral steroid usage|| Increase inhaled steroid dose to 2000 mcg/day to minimise oral steroids. Consider other treatments - refer to specialist. Methotrexate has been used in severe Asthma.
Patient involvement and education is fundamental at all stages.