Resp15 - Asthma

Question 1

3 features of asthma

Definition
Aetiology
Reversibility

Answer 1

1. ) Definition - chronic inflammatory airway disease w/ intermittent airway obstruction and hyper-reactivity
   - disease of small airways with variable expiratory airflow limitation
2. ) Aetiology - type 1 hypersensitivity reaction
   - allergic reaction provoked by re-exposure to a specific type of antigen (allergen)

3.) Reversible - either spontaneously or with a bronchodilator

Question 2

4 causes of narrowed airways in asthma

Airway Smooth Muscle
Epithelium
Mucus
Inflammatory Cells

Answer 2

1.) Airway Smooth Muscle - thickening, constriction, and hyperresponsiveness

2. ) Epithelium - sub-epithelial inflammation and fibrosis
   - shedding, basement membrane thickening

3.) Mucus - impaired mucus clearance and hypersecretion by goblet cells

4. ) Inflammatory Cells - increased neutrophils and/or esosinophils in airway lumen
   - due to increased inflammatory response due to cytokines, histamines, leukotrienes, prostaglandins

Question 3

4 diagnostic features of asthma

Signs and Symptoms x5
Precipitating/Risk Factors x8
Examination x5
Investigations x3

Answer 3

1. ) Signs and Symptoms
   - dry cough
   - nocturnal cough: parasympathetics constrict SMC
   - wheeze: forcing air through obstruction
   - SOB: narrowed airways
   - chest tightness
2. ) Precipitating/Risk Factors - age (young people)
   - allergens, dust, cigarette smoke, cold weather, exercise, infection, atopy (ezcema, hayfever, asthma)
   - medications: beta-blockers (contraindicated), adenosine (contraindicated),
   NSAIDs (caution, can cause bronchospasm, increased risk with nasal polyps)

3.) Examination - tachypnoea, tachycardia, hypoxaemia, bilateral wheeze on auscultation, atopic features

4. ) Investigations - spirometry shows obstructive features
   - volume-time graph: reduced FEV1:FVC ratio
   - flow-volume graph: scalloping
   - reversibilty with a bronchodilator
   - all adults should receive FeNO testing: will be raised in asthma
   - young patients with negative spirometry should also have FeNO testing

Question 4

Management of asthma

Probability Dependent
Non-Pharmacological
Pharmacological
Inhalers

Answer 4

1. ) Probability Dependent
   - high probability: start on treatment
   - intermediate: spirometry w/ reversibility testing
   - low probability: investigate/rule out other causes

2.) Non-Pharmacological - removal of potential triggers/precipitating factors

3. ) Pharmacological - target inflammation or bronchioles
   - inflammation: inhaled corticosteriods, monoclonal antibodies
   - bronchioles: beta-2 agonist (salbutamol), M3-antagonists (ipratropium bromide)
4. ) Inhalers - blue, brown, other
   - blue inhaler is the reliever (beta-2 agonist, salbutamol)
   - brown inhaler is the preventer (ICS)
   - other colours contains a mixture

Question 5

5 signs of acute severe asthma

Answer 5

1. ) Breathlessness- unable to speak in full sentences
2. ) Tachypnoea - RR > 25
3. ) Tachycardia - bpm > 115
4. ) Mild Hypoxaemia - SATS between 92-96%
5. ) Reduced PEF - 33-50% decrease from normal

Question 6

6 signs of life-threatenening asthma

Answer 6

1.) Hypoventilation - low respiratory rate

2. ) Silent Chest - not breathing properly
   - extreme sign which is very dangerous
3. ) Hypoxaemia - SATS < 92%
4. ) Central Cyanosis
5. ) Hypotension
6. ) Reduced PEF

Question 7

Management of acute severe/life threatening asthma

5 things

Answer 7

1. ) Oxygen - inhaled O2
2. ) Steroids - Hydrocortisone (IV)
3. ) Bronchodilators - salbutamol (nebuliser), ipratropium bromide (M3 antagonist), theophylline, mg sulphate
4. ) ADMIT - also call the anaesthetist
5. ) Chest X-Ray - rule out pneumothroax