Asthma

• What type of disease is asthma classified as?

  Asthma is a chronic inflammatory airway disease.
• What leads to variable airway obstruction in asthma?

  The smooth muscle in the airways is hypersensitive and constricts in response to stimuli.
• How is bronchoconstriction in asthma treated?

  Bronchoconstriction is reversible with bronchodilators, such as inhaled salbutamol.
• What are some other atopic conditions associated with asthma?

  Other atopic conditions include eczema, hay fever, and food allergies.
• What is the relationship between atopic conditions?

  Patients with one atopic condition are more likely to have others, and these conditions often run in families.
• When does asthma typically present?

  Asthma typically presents in childhood but can occur at any age.
• What is adult-onset asthma?

  Adult-onset asthma refers to asthma presenting in adulthood.
• What is occupational asthma?

  Occupational asthma refers to asthma caused by environmental triggers in the workplace.
• How does the severity of asthma symptoms vary?

  The severity of symptoms of asthma varies enormously between individuals.
• What are acute asthma exacerbations?

  Acute asthma exacerbations involve rapidly worsening symptoms and can quickly become life-threatening.
• What are the typical symptoms of asthma?

  • Shortness of breath
  • Chest tightness
  • Dry cough
  • Wheeze
• How do asthma symptoms fluctuate?

  Symptoms are episodic, with periods of worsening and improvement, and show diurnal variability, typically worse at night.
• How should asthma symptoms respond to bronchodilators?

  Symptoms should improve with bronchodilators; no response reduces the likelihood of asthma.
• What is a key finding during the examination of a patient with asthma?

  A key finding is a widespread “polyphonic” expiratory wheeze.
• What does a localized monophonic wheeze indicate?

  A localized monophonic wheeze is not asthma and may indicate an inhaled foreign body, tumor, or mucus plug.
• What is the next step if a localized wheeze is found?

  A chest x-ray is the next step if a localized wheeze is found.
• What are typical environmental triggers for asthma symptoms?

  • Infection
  • Nighttime or early morning
  • Exercise
  • Animals
  • Cold, damp, or dusty air
  • Strong emotions
• How can beta-blockers affect asthma?

  Beta-blockers, particularly non-selective ones, can worsen asthma symptoms.
• What test is used to establish objective measures of lung function in asthma?

  Spirometry is the test used to establish objective measures of lung function.
• What does spirometry measure?

  Spirometry measures volumes of air and flow rates during different breathing exercises.
• What FEV1:FVC ratio suggests obstructive pathology?

  A FEV1:FVC ratio of less than 70% suggests obstructive pathology.
• What is reversibility testing in asthma?

  Reversibility testing involves giving a bronchodilator before repeating spirometry to see if it impacts the results.
• What increase in FEV1 supports a diagnosis of asthma during reversibility testing?

  A greater than 12% increase in FEV1 supports a diagnosis of asthma.
• What does fractional exhaled nitric oxide (FeNO) measure?

  FeNO measures the concentration of nitric oxide exhaled by the patient, which is a marker of airway inflammation.
• What FeNO level is considered a positive test result for asthma?

  A FeNO level above 40 ppb is a positive test result supporting a diagnosis of asthma.
• How can smoking affect FeNO results?

  Smoking can lower the FeNO, making the results unreliable.
• How is peak flow variability measured?

  Peak flow variability is measured by keeping a peak flow diary with readings at least twice daily over 2 to 4 weeks.
• What peak flow variability percentage supports a diagnosis of asthma?

  A peak flow variability of more than 20% is a positive test result supporting a diagnosis of asthma.
• What is direct bronchial challenge testing?

  Direct bronchial challenge testing uses inhaled histamine or methacholine to stimulate bronchoconstriction, reducing FEV1 in asthma patients.
• What PC20 level indicates a positive test result in bronchial challenge testing?

  A PC20 of 8 mg/ml or less is a positive test result.
• What are the initial investigations recommended by NICE for suspected asthma?

  • Fractional exhaled nitric oxide (FeNO)
  • Spirometry with bronchodilator reversibility
• What should be done if there is diagnostic uncertainty after initial investigations for asthma?

  The next step is testing the peak flow variability.
• What is the next step if there is still uncertainty after peak flow variability testing?

  The next step is a direct bronchial challenge test with histamine or methacholine.
• What do the BTS/SIGN guidelines recommend for asthma diagnosis?

  • Categorizing patients into high, intermediate, or low probability of asthma
  • Assessing response to treatment before making a diagnosis if there is a good response
• How do the GINA guidelines differ regarding asthma diagnosis?

  • GINA suggests that FeNO testing is not useful in making or excluding a diagnosis of asthma.
• What are beta-2 adrenergic receptor agonists used for?

  Beta-2 adrenergic receptor agonists are bronchodilators that open the airways.
• How does adrenalin affect the airways in asthma?

  Adrenalin acts on the smooth muscle of the airways to cause relaxation and dilation of the bronchioles.
• What is the effect of blocking bronchial smooth muscle receptors in asthma treatment?

  It dilates the bronchioles and reverses bronchoconstriction.
• What is an example of a leukotriene receptor antagonist?

  Montelukast
• What role do leukotrienes play in asthma?

  They cause inflammation, bronchoconstriction, and mucus secretion in the airways.