Asthma

Question 1

What is asthma?

Answer 1

Asthma is chronic inflammatory airway disease characterised by intermittent airway obstruction and hyper-reactivity.

It is a disease of small airways with variable expiratory airflow limitation.

The inflammation is usually reversible, either spontaneously or with treatment.

Question 2

Why it important to know about asthma?

Answer 2

It is very common

2016 - 1420 people died from asthma

Question 3

What is the pathophysiology of asthma?

Answer 3

Initially a type 1 hypersensitivity reaction.

Airway smooth muscle:

• Hyperresponsiveness
• Constriction
• Thickening

Sub-epithelial inflammation and fibrosis

Mucus hypersecretion and impaired mucus clearance

Increased eosinophils and/or neutrophils in airway lumen.

Destroyed cilia

Question 4

What is a type 1 hypersensitivity reaction?

Answer 4

First exposure to allergen

Array of immune responses generate IgE antibody.
This plants itself on mast cells (and other immune cells)

Next time allergen - cross linking of IgE antibodies as releases lots of mediators (histamine and leukotrienes).

Called Mast cell degranulation.

Results in bronchoconstriction and inflammation.

Question 5

How does asthma present?

Answer 5

Cough - dry, nocturnal
Wheeze
Breathlessness
Chest tightness

Question 6

What are some precipitating factors of asthma?

Answer 6

Allergens - pollen, pets
Dust
Cigarette smoke
Cold weather
Exercise 
Cold weather 
Infection 
Aerosols

Question 7

How does asthma present?

Answer 7

Examination:
Respiration rate (raised)
Pulse 
Oxygen salts 
Wheeze 
Atopy - often presents alongside eczema and hayfever

Question 8

How is asthma diagnosed?

Answer 8

Peak flow - graph

Spirometry - obstructive style

Question 9

What is the difference between asthma and COPD?

Answer 9

Asthma: 
Dry cough
Wheeze
History of atopy
Obstruction Pattern 
Good ‘reversibility’ 

COPD:
Productive cough 
Wheeze
History of smoking 
Obstructive pattern 
Poor ‘reversibility’

Reversibility - when given bronchodialator, improves

Question 10

How does asthma management depend on the probability of having the condition?

Answer 10

Management depends on probability of asthma

High probability - start on treatment

Low probability - Investigate / rule out other causes, refer for further investigations

Intermediate probability - spirometry with reversible testing

Question 11

How is asthma managed (secondary prevention)?

Answer 11

Remove the triggers (if possible)

• Pets
• Dust
• Smoke
• Occupational
• Vaccination

Pharmacological - inhaled cortical steroids (Inhailer) - short acting B2 agonist as required (salbutamol).
If no better, add long acting B2 steroid.

Question 12

What are the different colour inhalers?

Answer 12

Blue - reliever - Salbulamol - B2 agonist

Brown - Preventer - Steroid

Orange + Green = Purple - Seratide

Question 13

What is the difference between acute severe and life threatening asthma?

Answer 13

Acute severe: 
Not able to complete full sentences 
Wheeze
Oxygen > 92%
Respiration rate > 25
Heart rate > 110 
Peak flow 33%-50%

Life threatening:
Exhausted 
Silent chest
Drowsy (could even by coma)
Central cyanosis 
Bradycardic
Oxygen < 92%
Peak flow < 33%

Question 14

How do you manage acute asthma?

Answer 14

Oxygen

Short acting B2 agonist - Salbutamol nebuliser

Steroids (Prednisolone or hydrocortisone) - oral for short periods only

Admit them

Consider adding other medications

GP follow up after discharge.

Consider chest X-Ray as asthmatics are more at risk of pneumothorax