Asthma Flashcards
Define asthma?
Chronic inflammatory airway disease characterised by variable reversible airway obstruction, airway hyper-responsiveness and bronchial inflammation
What are the genetic risk factors for asthma?
Family History
Atopy (tendency for T lymphocytes to drive production of IgE on exposure to allergens)
What are the environmental factors?
House dust mites Pollen Pets Cigarette Smoke Viral Respiratory Tract Infections Aspergillus Fumigatus Spores Occupational Allergens
What is the epidemiology of asthma?
Affects 10% of children
Affects 5% of adults
Prevalance appears to be increasing
What are the presenting symptoms of asthma?
Episodic History
Wheeze
Breathlessness
Cough (worse in the morning and at night)
What’s important to ask when talking about asthma?
Ask about previous hospitalisation due to acute attacks - this gives an indication of the severity of the asthma
What are the precipitating factors of Asthma?
Cold Viral Infection Drugs (e.g. beta-blockers, NSAIDs) Exercise Emotions Check for history of atopic disease (e.g. allergic rhinitis, uritcaria, eczema)
What are the signs of asthma on physical examination?
Tachypnoea Use of accessory muscles Prolonged expiratory phase Polyphonic Wheeze Hyperinflated chest
What are the signs of a Severe Attack of Asthma?
PEFR < 50% predicted
Pulse > 110/min
RR > 25/min
Inability to complete sentences
What are the signs of a Life-Threatening Attack of asthma?
PEFR < 33% predicted Silent Chest Cyanosis Bradycardia Hypotension Confusion Coma
What are the acute appropriate investigations for asthma?
Peak Flow Pulse oximetry ABG CXR FBC CRP U&Es Blood and sputum cultures
Why do we do a Chest X-Ray (CXR)?
To exclude other diagnoses e.g. pneumonia, pneumothorax
What might we see on a FBC?
Raised WCC if infective exacerbation
What are some of the investigations we might do in chronic asthma?
Peak flow monitoring
Pulmonary Function Test
Bloods to check Eosinophilia, IgE level, Aspergillus antibody titres
Skin Prick Tests
What would we expect to see if we monitored peak flow?
Often shows diurnal variation with a dip in the morning