Clinical features of Asthma Flashcards
What are the clinical features of Asthma?
Disease or Syndrome for which there is no universally accepted definition.
Increases responsiveness of the trachea and bronchi to various stimuli.
Widespread narrowing of airways.
What are Symptoms of asthma?
Wheezing, Coughing, Shortness of breath, chest tightness together with difficulty in expiration.
Why is asthma important?
Common, Dangerous, Expensive
What is the scale of asthma in the UK?
5.4 million people living with asthma.
3 families affected everyday with a death due to asthma.
In children, is asthma more common in males or females?
Males
In adults, is asthma more common in males or females?
Females
What happens to airways during an asthmatic attack?
Air is trapped in the alveoli.
Tightened smooth muscle. Wall inflames and thickened.
What are the proven risk factors of Asthma?
Hereditary, smoking, occupation
Explain the hereditary risks of asthma.
Disease clusters in families.
Risk increased with 1st degree family members or other atopic diseases.
What is Atopy?
Bodies predisposition to develop an antibody called immunoglobulin E in response to exposure to environmental allergens and is an inheritable trait.
What is atopy associated with?
Allergic rhinitis, asthma, hay fever, eczema.
What does maternal smoking during pregnancy cause?
Decreased Forced expiratory volume. Increased Wheeze, airway responsiveness and asthma.
What are the occupational risks?
Isocyanates (paint), Colophony (welding), Lab animals, grains, enzymes, Drugs, Crustaceans.
What are other possible risks of asthma?
Obesity, diet, ‘hygiene hypothesis’
What are the clinical aspects of asthma?
History most important. Investigations can be supportive. NO single test.
What signs can you look for in diagnosis.
Recurrent episodes, Absence of other symptoms, wheeze, personal history of atopy, variable FEV, sputum (occasionally), Cough (Usually dry)
What variations are common in Asthma?
Daily variation (night/morning), Weekly (Occupation/better at weekends/holiday), Annual (environmental allergens)
What are common triggers?
Exercise, cold air, cigarette smoke, perfumes, URTI, pets, tree or grass pollen, food, drugs (aspirin or NSAIDS)
What are important aspects of PMH?
Childhood asthma, bronchitis or wheeze. Eczema. Hayfever.
Important aspects of Drugs?
Current inhalers and compliance, B-blockers, Aspirin, NSAIDS, effect of previous drugs.
Importance of Social history?
Tobacco, recreational drugs, vaping, Pets, occupation, psychological aspects.
Clinical examination for Asthma diagnosis?
Breathlessness on exertion, Hyperinflated chest, Wheeze
Probably not asthma if…
Finger clubbing, Stridor, Asymmetrical expansion, dull percussion note, Crepitations
If not asthma, what else?
COPD, Bronchiectasis, Cystic fibrosis, Tumour, foreign body
Explain a spirometry test?
Rather FEV values. If the volume is reduced then the airways are obstructed. However peak may be completely normal and still have asthma.
If airways are obstructed, what other test can be carried out? and what does it exclude?
Full pulmonary function testing with CO transfer to Hb. Decreased think of COPD. (excludes COPD/emphysema)
What is a reversibility test?
Response to bronchodilator using salbutamol. Significant reversibility = >12 baseline
What are oral corticosteroids?
Anti-inflammatory - separates COPD from asthma.
If Spirometry is normal, what tests can be carried out?
Peak flow meter and chart, twice daily for 2 weeks. Look for morning/night dips.
What are other specialist investigations that can be carried out?
Airway responsiveness to Mathacholine, Histmine and mannitol. Exhaled Nitric oxide (FeNO)
What are other useful investigations?
Chest x-ray, skin prick (atopy) Total and specific IgE, Full blood count (eosinophilia)
Features of Moderate Asthma?
Able to speak. HR<110, RR<25, PEF (peak expiratory flow) 50-70% predicted or best, SaO > 92%, PaO > 8kPa
Features of Severe Asthma?
Inability to complete sentences in one breath. HR > 110. RR >25, PEF 33-50% predicted or best. SaO > 92%. PaO > 8kPa
Features of life threatening asthma?
Grunting, Impaired consciousness, confusion, exhaustion. Bradycardia, arrythmia, hypotension.
PEF < 33%. Cyanosis, Silent chest, poor respiratory effort.
SaO < 92%. PaO < 8kPa. PaCO normal
Near fatal symptoms?
Raised PaCO2, need for mechanical ventilation.
Main Points?
Symptoms variable and intermittent.
Demonstrate airway obstruction.
Reversibility to bronchodilators and corticosteroids.
Variable airflow obstruction: Peak Flow chart.
