Asthma Flashcards
Define Asthma and describe what it is characterised by
chronic inflammatory disorder of the airways
Reversible bronchospasm resulting in airway obstruction
List 5 behavioural/ familial risk factors of asthma
Personal/ FH of atopy
Antenatal: maternal smoking, infection (esp. RSV)
LBW
Not being breastfed
Maternal smoking around child
List 3 environmental risk factors for asthma
Exposure to high conc. allergens e.g. House dust mites
Air pollution
Hygeine hypothesis
What do atopic patients with asthma also suffer from?
Other IgE mediated atopic conditions:
Atopic dermatitis (Eczema)
Allergic rhinitis (Hay fever)
What drug are a number of patients with asthma sensitive to?
Aspirin
What percentage of adult asthma is occupational asthma? How is this identified?
10-15% related to allergens in workplace e.g. isocyanates + flour
Reduced peak flows during working week + normal readings when not at work
List 3 presenting symptoms of asthma
Cough (often worse at night)
Dyspnoea
“Wheeze”, “Chest tightness”
Give 2 signs of asthma
Expiratory wheeze on auscultation
Reduced peak expiratory flow rate (PEFR)
What spirometry results are seen in asthma?
FEV1: significantly reduced
FVC: normal
FEV1/FVC <70%
Which patients with suspected asthma should have objective diagnostic testing?
All >5 years
What investigations should adults with suspected asthma have?
Spirometry with bronchodilator reversibility test (BDR)
FeNO test
If asthma symptoms are better when away from work, how should the patient be investigated?
Serial measurements of PEFR at work + away from work
Refer to specialist as possible occupational asthma
What investigations should children with suspected asthma have?
- Spirometry with bronchodilator reversibility test (BDR)
- FeNO if normal or obstructive spirometry with -ve BDR
What does FeNO testing show?
Levels of inducible nitric oxide rise in inflammatory cells (esp. eosinophils) + correlate with levels of inflammation
What FeNO results are considered positive in adults and children?
Adults >40 parts per billion
Children >35 parts per billion
What is considered as positive in reversibility testing for asthma in adults and children?
Adults: improvement in FEV1 by >,12% + increase in volume of >,200ml
Children: improvement in FEV1 by >,12%
Asthma may be diagnosed in adults meeting any of which 5 criteria?
- FeNO >,40 ppb
- Post-bronchodilator improvement in lung volume of 200 ml
- Post-bronchodilator improvement in FEV1 of >,12%
- PEFR variability of >,20%
- FEV1/FVC ratio <70%
Describe the stepwise management of asthma in adults
- SABA + Low dose ICS
- SABA + Low dose ICS + LTRA
- SABA + Low dose ICS + LABA +/- LTRA
- SABA +/- LTRA
Switch ICS/ LABA to MART (inc low dose ICS) - SABA +/- LTRA + medium dose ICS MART
What is an alternative to medium dose ICS MART?
Changing back to a fixed dose of a moderate ICS + separate LABA
What management is required for patients with asthma not responding to SABA, LTRA and medium dose ICS MART?
Refer to specialist
Increase ICS to high dose (as fixed dose regime, not MART)
Trial additional drug e.g. long acting muscarinic receptor antagonist or Theophylline
What constitutes a low, medium and high dose ICS using budesonide or equivalent?
Low: <400 micrograms
Med: 400-800 micrograms
High: >800 micrograms