Asthma Flashcards
What is asthma?
chronic inflammatory disorder of the airways secondary to hypersensitivity.
What factors increase the risk of developing asthma?
- personal or family history of atopy
- antenatal factors (maternal smoking, viral infection during pregnancy - especially RSV)
- Low birth weight
- not being breastfed
- smoking around child
- exposure to high conc. of allergens
- air pollution
What other IgE-mediated atropic conditions do people with asthma also often suffer from?
- Atopic dermatitis (eczema)
- allergic Rhinitis (hay fever)
What drug are some asthma patients sensitive to?
Aspirin
What do patient most sensitive to asthma often suffer from?
Nasal polyps
What are symptoms of Asthma?
- Cough: often worse at night
- dyspnoea
- ‘wheeze’
- ‘chest tightness’
What are signs of Asthma?
- expiratory wheeze on auscultation
- reduced peak expiratory flow rate (PEFR)
What is spirometry?
a test which measure the amount (volume) and speed (flow) of air during exhalation and inhalation.
What is spirometry helpful in?
categorising respiratory disorders as either obstructive (where there is obstruction to airflow, examples include bronchoconstriction in asthma) or restrictive (where there is restriction to the lungs, examples include lung fibrosis)
What is FEV1?
Forced expiratory volume - volume that has been exhaled at the end of the first second of forced expiration.
What is FVC?
Forced Vital capacity - volume that has been exhaled after a maximal expiration following a full inspiration.
What are typical spirometry results in an asthma patient?
- FEV1: significantly reduced
- FVC: Normal
- FEV1% (FEV1/FVC): <70%
What else might be exhaled in asthma patients?
Fraction exhaled nitric oxide (FeNO)
What is the correlation between NO and Asthma and why?
Levels of NO typically correlate with levels of inflammation as one of the types of NOS is inducible (iNOS) and levels tend to rise in inflammatory cells, particularly eosinophils.
What other investigation may be considered, especially in older patients or those with a history of smoking?
Chest X-ray