Asthma Flashcards
(34 cards)
What are the three main characteristics of Asthma?
- Airflow limitation
- Airway hyperresponsiveness
- Inflammation of bronchi
Why do you get narrowing of the airways in Asthma?
- Smooth muscle contraction
- Smooth muscle hypertrophy
- Mucus hypersecretion
What are the two subsets of eosinophilic asthma?
- Atopic
- Nonatopic
What is atopic asthma?
- Usually present in children and is due to allergies
- IgE mediated reactions to common aeroallergens
What is nonatopic asthma?
- Develops later on and isn’t due to allergen exposure
- Airway obstruction is usually due to exercise, cold air and stress
What is the pathophysiology of atopic asthma?
- T cells recruit eosinophils which then damage the epithelium
- Inflammation = excess mucus production
- Narrowing of airways
- Remodelling of airway - collagen and matrix proteins
What is non-eosinophilic asthma?
- Has a later onset
- Affects 50% of patients
- Neutrophils instead of eosinophils
- Smoking and obesity association
What are the risk factors for asthma?
- Atopy
- Nasal polyploidy
- House dust mites
What is the presentation of asthma?
- Episodic wheeze (polyphonic and expiratory)
- Cough, SOB
- Diurnal variation - worse between 3-5am
- Intermittent dyspnoea
- Hyperinflated chest
What questions would you ask to assess for asthma?
- Provoking factors
- Severity levels
- History of complaint
- Associated symptoms
- Drugs
- Family/social history
- Occupational history
What differs COPD from asthma in presentation?
COPD presents later and mainly in smokers, more relentless SOB with wheeze, less diurnal variation and sputum production
How does fibrosis differ from asthma in terms of presentation?
Presence of crackles in fibrosis
What investigations would you do in asthma?
- Physical examination
- Tests (CXR, bloods, skin prick)
- Lung function tests
What would you find on a physical examination in asthma?
- May be normal as asthma is episodic
- Polyphonic expiratory wheeze
- No crackles and no sputum
- Might have a hyper inflated chest
What would you check for on the blood test of an asthmatic?
Eosinophils
What would spirometry/peak flow show in asthma?
- Reduced FEV1
- FEV1/FVC <70%
- PEFR reduced than expected
- Increased responsiveness to challenge agents
What would you see on an exhaled nitric oxide test in asthma?
- Marker of eosinophils inflammation in lung
What would reversibility testing show in asthma?
- Increase in 12% FEV1 and increase of 200ml in FEV = positive test
- > 400ml increase means asthma is highly likely
- 20% variability of PEFR also suggests asthma
What defines severe asthma?
Has to have 1 major and 2 minor of the following:
Major:
- Treatment with continuous or near continuous oral steroids
- Requirement for high dose inhaled steroids
Minor:
- Additional daily reliever medication (beta agonists, theophylline, LTRA),
- Symptoms needing reliever medication on daily or near daily basis
- Persistent airway obstruction (FEV1 = 20%)
- > 1 emergency visit per annum
- > 3 steroid courses per annum
- Prompt deterioration with 25% reduction in oral or inhaled steroid dose
- Near fatal event in the past
What would present a risk of death due to asthma?
- > 3 classes of treatment
- Recent admission/frequent attender
- Previous near fatal disease
- Brittle disease
- Psychosocial factors
What for classifications are there for asthma attacks?
- Uncontrolled/moderate
- Severe
- Life threatening
- Near fatal
Patient presents with PEFR >50% predicted, RR<25 and HR<110. How would you classify this asthma attack?
Uncontrolled/moderate
Patient presents with PEFR <33%, PaO2 <8kPa and altered consciousness levels, exhaustion, arrhythmia, hypotension, cyanosis. How would you classify their asthma attack?
Life threatening: would only need to have one of those symptoms
Patient presents with
- PEFR 33-50% predicted
- RR > 25
- HR >110
- Inability to complete sentences
Severe: Would only need to have one of those symptoms
