| What are some characteristics of chronic Asthma | Airway inflammation
Reversible airflow obstruction
Increase in airway responsiveness
Airway remodelling |
| What is the main difference between extrinsic and intrinsic asthma | Extrinsic has FH atopy where there is IgE produced on contact with normally a harmless environment, and also has a early onset compared to Intrinsic which is adult onset and is often associated with bronchitis or cold or can be exercise induced |
| What cell drives the process of inflammation | Th2 cells which release cytokines which attract inflammatory cells including MAST cells and eosinophils |
| What are the three phases of extrinsic asthma | Early ( 15 minutes ) --> cross linkages of two IgE on mast cells causing degranulation
Late ( 4 hours ) --> After recovery from mediators from mast cells, then activation of macrophages and chemotaxis and eosinophils into the lining of the bronchi
Prolonged hypersenstivity ( days ) --> Exaggerated response of airway after exposure , inflammatory cells in the bronchial walls continue giving loss of epithelial cells |
| What are some differences between a normal lung and a asthmatic lung | Airway remodelling
Hypertrophy and hyperplasia of smooth muscle
Hypertrophy of mucus glands
Thickening of the basement membrane |
| On a spirometer, what would asthma look like? | Obstructive pattern
Reduced FEV1/FVC ratio
Obstructive flow volume loop |
| For diagnosis of asthma, what recurrent symptoms do you need to find | Wheeze
Breathlessness
Chest tightness
Cough
Variable airflow obstruction |
| What is some investigations that can be used for asthma | Spiromtery
Allergy testing --> Skin prick or blood IgE levels
Exhaled Nitricoxide
Chests X-rays --> generally normal in chronic |
| What are some management plans for asthma | Drugs
Primary prevention
Education
Manage life threatening asthma |
| What are some drugs that can be used to treat asthma | Airway relaxants :
- Beta2 agonists (short & long acting)
- Muscarinic antagonists (ipratropium b
- Theophylline/aminophylline
Anti-inflammatory agents (‘preventers’)
- Corticosteroids
- Leukotriene receptor antagonist |
| What is Status Asthmaticus | Medical emergency
Where the acute severe asthma causing the airway obstruction is unresponsive to drug therapy |
| What causes the narrowing of the airways | Mucosal swelling
Thickening of bronchial walls due to infiltration of by inflammatory cells
Mucus overproduction; the mucus is also abnormal- it is thick, tenacious & slow moving --> mucus plugs
Smooth muscle contraction
The epithelium is shed and is incorporated into the thick mucus. The inflammation also causes hyper responsiveness of airways to nonspecific stimuli |
| What is the classification for severe asthma | Pulse > 110 beats per minute
Respiratory rate > 25
Cannot complete sentences in a single breath
PEFR - 33%-50% |
