Session 5 - Asthma Flashcards
Describe the epidemiology of asthma
- Increasing in prevalence
- More common in the developed world
- Increases in populations who move from developing to developed countries
How many adults currently receive tratment for asthma?
• 5.4 million
What are the potential causes of asthma?
• Genetic risk • Sensitisation to airborne allergens ○ House dust mite ○ Pollens ○ Air pollution ○ Tobacco smoke • Hygiene hypothesis
hat is the definition of asthma?
• One or more of the following recurring symptoms ○ Wheeze ○ Cough ○ Breathlessness ○ Chest tightness ○ Variable airflow obstruction
What is a wheeze?
- High pitched expiratory sound
- Originates in airways compressed or obstructed
- Wheeze is of variable intensity and tone
Outline the type of cough one may develop in asthma
- Cough that’s worse at night
- Cough which is exercise induced
- Dry cough
What are the three parts of the examination of a suspected asthma patient?
- Inspection
- Percussion
- Auscultation
What do you look for in the inspection of an asthma patient?
• Chest ○ Scars/deformities ○ Hyper expansion • General health ○ Eczema, hay fever ○ Lethargu ○ Can they speak?
What are you looking for in percussion of an asthma patient?
• Hyper-resonance
What are you looking for in auscultation of an asthma patient?
• Polyphonic wheeze
Give three tests used in the investigation of an asthma patient?
- Spirometry - Flow volume loop
- Allergy testing
- Chest x-rays
What will you see in the spirometry of an asthmatic?
- Low PERF?
- Low FEV/FVC ratio
- > 12% increase in FEV1 following salbutamol
What will you see in the allergy testing of an asthmatic?
- Skin prick to aero allergens
* Blood IgF levels to specific aero-allergens
What will you see in Chest X ray of asthmatic?
• Peformed to exclude other disease/inhalation of foreign body/pneumothorax
Outline the pathophiologyical changes underlying asthma
- Increased mast cells
- Increased eosinophils
- Increased dendritic cells
What role do mast cells play in asthma?
• Release prostaglandins/histamine
What role do eosionphils play is asthma?
Large numbers in bronchial wall of asthmatics
What role do dendritic cells and lymphocytes have in asthna?
- Dedritic cells have a role in the initial uptake and presentation of allergens to lymphocytes
- T-Helper lymphocytes (CD4) release cytokines that play a key part in the activation of mast cells
- Th2 phenotype favour the production of antibody production by B lymphocytes to IgE.
What occurs in remodelling in asthma?
• Epithelium
○ Stressed and damaged with a loss of ciliated columnar cells
• Basement membrane
○ Deposition of collagens, causing it to thicken
• Smooth Muscle
○ Hyperplasia causing thickening of the muscle
Give three causes of asthmatic attacks?
- Lack of treatment adherence
- Respiratory virus infections associated with common cold
- Exposure to allergens or triggering drug
What are three treatments for asthma?
- Education
- Primary prevention
- Pharmacological management
What does education do for asthma patients?
• Educates people to correctly recognise their symptoms
○ To use services appropriately
○ To develop own personal asthma action plan
What is primary prevention of asthma?
- Stop smoking
- Get fresh air
- Reduce exposure to allergens
- Lose weight
What is involved in the pharmacological management of asthma?
• B2 adrenoagonists
○ Muscarinic antagonists
• Anti inflammatory agents
