L10- Airway diseases

Question 1

What does FEV1/FVC show?

Answer 1

• <0.7 airflow obstruction
• normal or elevated- restriction- tends to impair FVC greater than FEV1
• Flow volume loop

Question 2

What is asthma?

Answer 2

• Chronic inflammatory disorder of the airways leading to airflow obstruction
• variable airflow obstruction
  
  • > 12% increase in FEV1 post bronchodilator and >200ml
  • Diurnal variability >20% on PEFR
• airwy hyperresponsiveness
• associated ith atopy/allergy

Question 3

What are the symptoms of asthma?

Answer 3

• Coughing
• Wheezing
• Chest tightness
• shortness of breath

Question 4

What are the causes of asthma?

Answer 4

• atopic/allergic- allergen- t cell response
• IgE mediated- released by B cells
• leukotrienes/histamine related- mast cell release due to exposure to allergen
• eosinophilic inflammation driven
• Bacteria/prenatal componenent, viruses, pollution

Question 5

How does asthma cause airflow obstruction? Which changes are temporary and which ones are permanant

Answer 5

Temporary

• Airway wall inflammation- swelling of the epithelium
• Airway wall smooth muscle contraction

Permanent

• Airway wall scarring- caused by uncontrolled inflammation

Temporary or permanent

• Mucous secretion- dependent on how well inflammation is controlled

Question 6

What is good asthma control?

Answer 6

• no daytime symptoms
• no night time awakenings due to asthma
• no need for reliever medication
• no exacerbations
• no limitation of physical activity
• Normal lung function(FEV1) and PEF>80% predicted

Question 7

What are the triggers for asthma

Answer 7

• Allergens
  
  • moulds, fust mites, animal dander, pollens, food
• Irritants
  
  • Second hand smoke, aerosols, volatile organic compounds, ozone, particulate layer
• Other
  
  • Viral respiratory infections
  • changes in weather
  • exercise
  • endocrine factors
    
    • Mentrual period, pregnancy

Question 8

Give some examples of occupational asthma

Answer 8

• Bakers- Flour dust
• Cleaners- Proteolytic enzymes
• Soldering- colophony
• Paint, varnishes, plastics, insulation- isocyanates

Question 9

How can asthma be managed?

Answer 9

Asthma management plan

• Identification of triggers and ways to reduce exposure
• medication
• peak flow monitoring
• emergency plan

Question 10

Treatment for asthma

Answer 10

• Beta 2 agonist- e.g. Salbutamol, salmeterol
  
  • bronchodilator- target smooth muscle contraction
• Steroids- e.g. fluticasone
  
  • targets inflammation

Question 11

How does inhaled steroids work?

Answer 11

• reduce inflammation
• improve lung function
• reduce exacerbations
• reduce oral steroid use- side effects
• reduce hospital admissions
• reduce mortality

Question 12

What is the stepwise approach to asthma medication?

Answer 12

• Step 1
  
  • SABA- Short acting beta 2 agonist- blue inhaler- Ventolin(salbutamol)
• Step 2
  
  • Low to moderate dose steroid inhaler (200-800µg/day) 400µg is a food starting dose + SABA
• Step 3
  
  • • LABA (long acting), if good response, continue
  • if poor response- increase the dose of steroid (up to 800µg/day)
  • if no response- stop LABA+ increase dose of steroid
• Step 4
  
  • Increase the dose of steroid- up to 2000µg/day
  • +try leukotriene receptor antagonist or theophylline
• Step 5
  
  • steroid tablets

Question 13

When is oral steroids used and why

Answer 13

• acute exacerbations
• rarely needed in maintenance therapy
  
  • lowest dose possible
  • SE’s include diabetesm osteoporosis, cataracts

Question 14

What is Omaluzimab?

Answer 14

• newer intervention
• anti IgE , used for patient with moderate to high IgE levels and on regular steroids
• Subcutaneous injections 2-4x/week
• benefits in QoL symptoms and exacerbations
• peak benefir 12-16weeks
• 2/3 respond

Question 15

What is COPD?

Answer 15

• characterised by airflow obstruction that is not fully reversible

Question 16

What is the cause of COPD

Answer 16

• Cigarette smoking causes inflammatory cells in lungs to secrete proteases and oxidants which leads to parenchymal damage and mucus hypersecretion
• Airway limitation is as a result of
  
  1. Airway inflammation-+ mucocillary dysfunction ->
  2. Strucutral changes in lungs ->
  3. bronchospasm- narrowing or airways ->
  4. Systemic changes in bloodstream which exacerbates the inflammation

Question 17

How can you assess COPD

Answer 17

Symptoms

• Sputum production
• breathlessness score- MRC dyspnoea score
• exacerbation frequency
• BMI- BODE index
• signs of right heart failure- hypoxia due to severe COPD
• spirometry- grade severity
• pulse oximetry

Question 18

How can you differentiate between asthma and COPD?

Answer 18

Question 19

Management for COPD

Answer 19

• Maximise brochodilation
  
  • SABA- s.g. salbutamol
  • LAMA- Long acting muscurinic antagonist- e.g. tiotropium
  • Combination long acting bronchodilators- LAMA/LABA- e.g. Ultibro
• Add inhaled steroid in selected patients- FEV1<50%, blood eosinphilia and frequent exacerbations
  
  • LABA/ICS+LAMA

Question 20

COPD co-morbidity?

Answer 20

Cardiovascular disease, ischaemic heart disease

Question 21

Effect of COPD on lung volumes and gas tranfer?

Answer 21

• lung volumes- gas trapping, damage and loss of recoil in lung parenchyma, leads to increased TLC but decreased FEV1
• damage to lung parenchyma- problem with diffusion from airway to capillary- reduction in gas transfer