Asthma Flashcards
Impact
315 million have it
340 000 deaths/year
5.4 mill in UK treated
£1 billion NHS
Onset
Childhood or middle age
Childhood 50% to become symptom free by 21
What causes obstruction
Bronchoconstriction
Mucous and bronchial secretions - from inflammation
Oedema of bronchial wall
Atopy in asthma
Asthma is linked to atopy
IgE antibodies to allergens
Family history of hay fever or eczema
Symptoms
Cough, wheeze, breathlessness, chest tightness
Worse at night or early morning
Triggering factors
Allergens, infections
Change in temp, exercise, stress, smells
Food additives, reflux, air pollution, tobacco
Certain drugs (aspirin, ibuprofen, beta blockers)
Making diagnosis
More than one symptom
Symptom free periods
History
Physical exam may be normal
Investigations
Peak flow Spirometry CXR Eosinophil count in blood FeNO (>40ppb) Skin prick for allergies Reversible with bronchodilators
PEFR expected results
20% diurnal variation - worse at night/early morning (15% improvement with bronchodilators
Management
Smoking cessation, weight reduction, pollution avoidance
Pharmacological (ICS, LABA, Oral treatment - montelukast and theophylline, SABA, Anti-IgE & anti IL-5 injections)
Two types of inhaler
Dry powder inhalers
Pressurised metered dose inhalers
Clinical features of Acute severe asthma
PEFR - 33-50% of best Can't complete sentences in one breath Resp >25/min Pulse >110 beats/min SpO2 <92% Silent chest, cyanosis, feeble resp effort Hypotension or arrhythmia Exhaustion, altered consciousness
Management of asthma
Oxygen Corticosteroids Nebulised bronchodilators IV MgSO4/IV aminophylline Intubation/ventilation?
