Asthma

Question 1

How many people are affected with asthma?

Answer 1

1 in 6 children

1 in 9 adults

Question 2

How many children grow out of asthma?

Answer 2

1/3-1/2

Question 3

What is the pathophysiology of asthma?

Answer 3

Acute
- Mediator release from mast cells and eosinophils in response to allergen
- Bronchoconstriction
- Oedema
- Mucus
Chronic inflammation
- Early structural changes involving
   - Cell recruitment
   - Epithelial damage
Airway remodelling
- Smooth muscle and goblet cell hyperplasia
- Thickening of basement membrane

Question 4

What mediators are released by mast cells and eosinophils?

Answer 4

Histamine
Prostaglandins
Leukotrienes
Cytokines

Question 5

What are the symptoms of an acute asthma attack?

Answer 5

SOB
Wheezing
Chest tightness
Cough
Reversible
May be certain triggers

Question 6

What are the features of shortness of breath in asthma?

Answer 6

Episodic
Particularly nocturnal/early morning
Often with exercise

Question 7

What are the predisposing factors for asthma?

Answer 7

Genetic predisposition
Atopy
Airway hyper-responsiveness
Sex - severe persistent asthma more common in women

Question 8

What are some triggers for asthma?

Answer 8

Allergens
Pollutants
Tobacco smoke
Occupational fumes
URTIs
Exercise
Changes in weather
Anxiety
Food/additives
Medication
- Aspirin
- Beta blockers
GORD

Question 9

What are the signs of asthma?

Answer 9

Normal exam if not active
During attack
- Anxiety
- Tachypnoea
- Cyanosis
- Bronchospasm > increased work of breathing and hyperinflation
   - Pursed-lip breathing
- Compensation through increased effort
   - Elevated RR
   - Accessory muscle activation
   - Substernal intercostal retraction
- Pulsus paradoxus

Question 10

Why do patients in an asthma attack do pursed-lipped breathing?

Answer 10

Auto end-expiratory pressure increase

Question 11

What are the auscultatory findings of an asthma attack?

Answer 11

Prolonged expiratory phase with polyphonic wheeze
Reduced breath sounds
Reduced heart sounds

Question 12

When does pulsus paradoxus occur?

Answer 12

In severe, life-threatening asthma

Question 13

What investigations can be carried out to confirm the diagnosis of asthma?

Answer 13

Peak expiratory flow: 20% variation day to day
Spirometry: improvement with bronchodilator
Bronchoprovation testing, if spirometry unremarkable

Question 14

Other than asthma, what can cause a wheeze?

Answer 14

Bronchitis
Bronchiectasis
Exacerbation of COPD
Vocal cord dysfunction
Obstructing endobronchial lesion
- Monophonic
Heart failure

Question 15

What are the goals of asthma management?

Answer 15

Control symptoms
Prevent exacerbations
Maximise lung function and prevent future lung function decline
Maintain normal levels of activity
Lowest dose of medication to achieve suitable asthma control and minimise side effects

Question 16

How are the goals of asthma management achieved?

Answer 16

Patient focused
- What are the patient's goals?
- Education
- Action plan
- Psychosocial factors
Avoid triggers
Treat conditions that could exacerbate asthma
Medications

Question 17

What is the mechanism of action of beta-2 agonists?

Answer 17

Relax smooth muscle
Improve airway patency
Symptom relievers > don’t change underlying inflammation

Question 18

What is the mechanism of action of inhaled corticosteroids?

Answer 18

Reduce airway

• Inflammation
• Hyper-responsiveness

Question 19

What medications can be used the in the management of asthma?

Answer 19

Beta-2 agonists
- Short-acting
- Long-acting
Inhaled corticosteroids
Oral corticosteroids
Combination inhalers
Leukotriene receptor antagonists
Long-acting anticholinergic
Anti-IgE

Question 20

What are the adverse effects of inhaled corticosteroids?

Answer 20

Local
- Hoarse voice
- Thrush > need to rinse mouth
Systemic
- Not common unless in very high dose

Question 21

Why might adherence in asthma management be poor?

Answer 21

Symptom remission
Multiple medications
Fear of dependence
Long-term side effects
Chronicity of asthma
Cost
Poor understanding
Cultural issues

Question 22

What is the acute management of an asthma attack?

Answer 22

Oxygen
Oral prednisolone/IV hydrocortisone
Regular bronchodilators
Urgent ICU assessment for
- Observation
- Possible intubation
IV magnesium

Question 23

What is the mechanism of action of magnesium in acute asthma management?

Answer 23

Inhibits ACh > inhibits smooth muscle contraction

Question 24

What are the risk factors for increased risk of death from asthma?

Answer 24

Previous life-threatening attack
Recent hospitalisation for asthma
Poor psychosocial supports
Poor adherence to preventive treatments
Difficulty accessing treatment