Asthma Flashcards
Describe in outline, the pathophysiology of asthma
Healthy lung –> asthmatic lung
Damage and repair, B cells –> IgE, oedema, thickening of walls, mucus, smooth muscle contraction
Radius of airway decreased –> flow decreases –> work of breathing must increase
Define asthma
A chronic disorder
Reversible airflow obstruction
Airway wall inflammation and remodelling
Increased airway smooth muscle thickness
Increase in airway responsiveness to a variety of stimuli
Describe the major precipitating factors for asthmatic attack
Histamine Cold air Exercise Air pollution Tobacco spores Animals
Describe the symptoms and signs of asthma and their pathological basis
Symptoms - wheeze, breathlessness, chest tightness, cough (often worse at night), variable airflow obstruction
Signs - eczema, hay fever, lethargy, hyper resonant during percussion, polyphonic wheeze during auscultation, chest deformity (barrel chest)
Describe the tests used to assess the condition of a patient suspected of asthma, and how they are interpreted
PEFR (with bronchodilator to determine reversibility) Spirometry (FEV1:FVC<70%) Bronchial hyper responsiveness (BHR) Allergy testing CXR
Describe, in outline, the principles of treatment of asthma
Education
Primary prevention - stop smoking, minimise exposure
Pharmacology:
Relaxants e.g. bronchodilator, B2 agonist - widen airway
Anti-inflammatory agents e.g. corticosteroids
What is a wheeze and why does it occur?
A high pitched noise due to small airways narrowing by compression/obstruction during expiration