Asthma clinical features in adults Flashcards
(34 cards)
What is asthma ?
History of respiratory symptoms such as :
- wheezing - SOB - coughing - chest tightness - together with difficulty in expiration
What is the epidemiology of asthma ?
Children- 10-15% - M>F
Adults- 5-10%- F>M
Dangerous- 3 deaths/day
What is the pathophysiology of asthma ?
Airway inflammation mediated by the immune system —> narrowing of airways
—> increased airway reactivity
I
V
Airway narrowing
I I
V V
spontaneously stimuli
What are the three proven risk factors ?
Smoking
Genetics
Occupation
What are the hereditary risk factors of asthma ?
Atopy is body’s predisposition to develop an antibody- IgE in response to exposure to :
- environmental allergens and is an inherited trait- allergic rhinitis, eczema, hay fever - increased risk of asthma if 1st degree family member has asthma or atopic disease
How is smoking a risk factor of asthma ?
Maternal smoking during pregnancy:
- decreased FEV1
- increased wheeze
- increased airway responsiveness
- increased asthma
likely an epigenetic phenomenaWhat allergens can occupation expose you to ?
Isocyanates (paints) Colophony (welding solder flux) Laboratory Animals Grains Enzymes Drugs Crustaceans
What is the most important clinical aspects of asthma ?
History
What are the symptoms of asthma ?
Wheeze SOB, severity Chest tightness Cough, paroxysmal, usually dry Sputum (occasional)
What are some triggers of asthma symptoms ?
Exercise Cold air Cigarette smoke Perfumes URTIs Pets Tree or grass pollen Food Drugs (aspirin/ NSAIDs)
What type of variation in asthma might help determine the trigger ?
Daily- nocturnal/ early morning
Weekly- occupation, better at weekends/holidays
Annual- environmental triggers
What features of drug use are important to consider when diagnosing asthma ?
Current inhalers (technique, dosage, compliance)
Beta blockers
Aspirin
NSAIDS (Nonsteroidal anti-inflammatory drugs)
Effects of previous drugs/ inhalers
What aspects of social history are important to consider when diagnosing asthma ?
Smoking
Pets
Occupations past/present
Psychosocial aspects - Psychosocial profile can affect asthma
What common health conditions are important to consider when diagnosing asthma ?
Childhood asthma, bronchitis
Eczema
Hay-fever
What are some differential diagnosis when investigating asthma ?
Generalised airflow obstruction:
- COPD - bronchiectasis - cystic fibrosis
Localised airway obstruction (inspiratory stridor= large airways)
- tumour - foreign body
Cardiac
When is it unlikely to be asthma ?
Cervical lymphadenopathy
Stridor
Asymmetrical expansion
Dull percussion note (lobar collapse, effusion)
Crepitations - crackling or rattling sounds) (bronchiectasis, CF, alveolitis, LVF)
What are the two positive findings for asthma ?
Airflow obstruction
Variability and or reversibility of airflow obstruction
How can spirometry determine if someone has obstructed airways ?
FEV1 < 80% predicted
FEV1/FVC < 70%
What do FEV1 and FVC tell us respectively ?
Airway diameter
Lung Capacity
After confirmation of obstructed airways, what is your next step in the diagnosis of asthma ?
Full pulmonary function tests
Confirmation of reversibility with B2 agonists and steroids
What is reversibility to bronchodilators ?
Response to bronchodilator
Baseline, 15 mins post 400microg inhaled salbutamol
Baseline, 15 mins post neb 2.5-5mg salbutamol
Interpretation:
- significant reversibility-> FEV1> 200ml and FEV1 > 12% baseline
If airways are not obstructed what is your next step in diagnosis ?
Peak flow monitoring
Bronchial provocation with nitric oxide
What is the purpose of full pulmonary function testing ?
Excluding COPD/emphysema
What is reversibility to oral steroids ?
Response to oral corticosteroids (anti-inflammatory) Separates COPD from asthma 0.6mg/kg prednisolone 14 days Peak flow chart and meter Baseline and 2 weeks spirometry
