Asthma Flashcards
Asthma is the most common chronic respiratory disorder encountered in clinical practice
true
What % affected children and adults?
10% of children and around 5-10% of adults
Asthma definition?
chronic inflammatory disorder of the airways secondary to type 1 hypersensitivity
symptoms are variable and recurring and manifest as reversible bronchospasm resulting in airway obstruction.
Risk factors?
personal or family history of atopy antenatal factors: maternal smoking, viral infection during pregnancy (especially RSV) low birth weight not being breastfed maternal smoking around child exposure to high concentrations of allergens (e.g. house dust mite) air pollution 'hygiene hypothesis':
A number of patients with asthma are sensitive to?
aspirin
atients who are most sensitive to asthma often suffer from?
nasal polyps
Signs & symptoms?
cough: often worse at night dyspnoea 'wheeze', 'chest tightness' expiratory wheeze on auscultation reduced peak expiratory flow rate (PEFR)
Is asthma obstructive or restrictive?
Obstructive
What are the typical spirometry results in asthma?
FEV1 - significantly reduced
FVC - normal
FEV1% (FEV1/FVC) < 70%
How should adults be diagnosed with asthma?
Exclude occupational asthma
all patients should have spirometry with a bronchodilator reversibility (BDR) test
all patients should have a FeNO test
How should patients aged 5-16 years be diagnosed with asthma?
all patients should have spirometry with a bronchodilator reversibility (BDR) test
a FeNO test should be requested IF:
- There is normal spirometry or
- Obstructive spirometry with a negative bronchodilator reversibility (BDR) test
How should patients aged< 5 years be diagnosed with asthma?
diagnosis should be made on clinical judgement
What is a FeNo positive test?
in adults level of >= 40 parts per billion (ppb)
in children a level of >= 35 parts per billion (ppb
What does a reversbility test measure?
FEV1
What is a positive reversibility test?
Adults: improvement in FEV1 of 12% or more and increase in volume of 200 ml or more
Children: FEV1 of 12% or more
How does FeNO work?
nitric oxide is produced by 3 types of nitric oxide synthases (NOS).
one of the types is inducible (iNOS) and levels tend to rise in inflammatory cells, particularly eosinophils
levels of NO therefore typically correlate with levels of inflammation.
What are steps 1-4 in asthma management for adults?
- Short-acting beta agonist (SABA)
- SABA + low-dose inhaled corticosteroid (ICS)
- SABA + low-dose ICS + leukotriene receptor antagonist (LTRA)
- SABA + low-dose ICS + long-acting beta agonist (LABA)
Continue LTRA depending on patient’s response to LTRA
When should you skip to step 2 in a new diagnosis of asthma for adults?
Newly-diagnosed asthma with symptoms >= 3 / week or night-time waking