Asthma Flashcards
Define asthma.
Asthma is a chronic inflammatory airway disease characterised by intermittent airway obstruction and hyper-reactivity.
Explain the aetiology/risk factors of asthma.
Patients’ genetic make-up may predispose them to hyper-responsiveness to environmental aetiological triggers. Those triggers include viral infections (e.g. rhinovirus, respiratory syncytial virus, human metapneumovirus, and influenza virus), bacterial infections (e.g. Mycoplasma pneumoniae or Chlamydia pneumoniae), allergen exposure (e.g. tree, grass, or weed pollen; fungi; or indoor allergens), occupational exposures (e.g. animal or chemical), food additives and chemicals (e.g. metabisulfites), irritants, or aspirin in predisposed people.
Summarise the epidemiology of asthma.
Asthma affects approximately 30 million people in Europe and more than 25 million people in the US. The global burden is reported to be 300 million people, potentially increasing to 400 million by 2025. In 2010, overall asthma prevalence in the US was 8.4%.
Recognise the presenting symptoms of asthma.
Recurrent episodes of dyspnoea, chest tightness, wheezing, or coughing typically occur.
The patient’s medical history may help to identify allergen exposures that worsen asthma: for example, episodes may be exacerbated by exposure to irritants such as tobacco smoke or fumes from chemicals, such as bleach. Attacks may occur seasonally or upon exposure to cats in allergic patients. Exercise can also make the symptoms worse.
Recognise the signs of asthma on physical examination.
The examination may be normal in patients with bronchial asthma. Examination of the nasal passages may reveal nasal polyposis or nasal congestion. Chest auscultation may reveal expiratory wheezes.
With more severe asthma, wheezes may be audible without the use of a stethoscope. In patients with severe exacerbations, the lung examination may be silent.
Identify appropriate investigations for asthma and interpret the results.
FEV1/FVC ratio - <80% of predicted
FEV1 - 20% drop is indicative
Peak expiratory flow rate (PEFR)
CXR - normal or hyperinflated
FBC - normal or raised eosinophils and neutrophils
Generate a management plan for asthma.
Salbutamol inhaler until in hospital.
Once in hospital, administer 2.5mg salbutamol and oxygen as a nebuliser back to back (or 5mg in one dose but this increases the risk of tremor etc). Give IV hydrocortisone or oral prednisolone depending on how bad the patient is.
Identify the possible complications of asthma and its management.
IV magnesium sulfate in life-threatening exacerbation of asthma.
Airway remodelling due to inflammation which leads to the airway resembling COPD.
Summarise the prognosis for patients with asthma.
People with asthma have the same life expectancy as normal people.
