Asthma

Question 1

Describe the epidemiology of asthma

Answer 1

Most commonly in children and middle age
50% if children with mild asthma grow out of it by 21
70% if children with more persistent asthma will continue it into adult life
Adult onset is more persistent

12000 deaths/year ; 40 children

PREVENTABLE

Question 2

Describe the 3 ways in which airflow obstruction can occur

Answer 2

1. Bronchoconstriction- contraction of smooth muscle in bronchial walls
2. Bronchial secretions and plugs of mucus- due to inflammation of the bronchial wall
3. Oedema of the bronchial wall- due to inflammation the lining mucosa of the bronchial wall

Question 3

Outline 5 risk factors for asthma

Answer 3

1. Atopy- the tendency to form IgE antibodies to allergens such as pollen, house dust mites or animals
2. Genetics
3. Obesity
4. Pollution
5. Occupational asthma

Associated with eczema and hay fever

Question 4

Briefly outline the pathophysiology of asthma

Answer 4

Antigen presents in airways

1. mast cells respond causing broncho constriction
2. eosinophils respond leading to inflammatory cascade and triggering bronchoconstriction

Question 5

Symptoms ?

Answer 5

Cough
Wheeze
Breathlessness
Tightness of chest

Symptoms may be episodic, worse at night, in response to exposure to triggers (exercise, injection)

Question 6

How is asthma diagnosed?

Which investigations may be used?

Answer 6

Mainly the history
Physical examination may be normal

CXR may be normal/show hyperinflation
FBC- increased eosinophil count in blood
Skin prick or blood tests (IgE) for allergens such as aspergillus fungi
lung function tests may show airflow obstruction
Peak flow monitoring
Bronchial challenge test
FeNO- measures airway eosinophilic inflammation drives up NO level in airways

Question 7

How is asthma managed?

Answer 7

Specialised treatment:

1. Desensitisation to proven inhalation allergens
2. Monoclonal anti-IgE antibody injections
3. Immunosuppresant therapy
4. Bronchialthermoplasty

Personal asthma action plan = what, why, who, indications

Question 8

What does uncontrolled asthma look like?

Answer 8

Difficulty sleeping
Usual asthma symptoms during day
Interference in usual activities

Question 9

Describe acute severe asthma

Answer 9

MEDICAL EMERGENCY

PEF 33-50% best or predicted
Cant complete sentences
Resp rate > 25 beats/min, pulse 110bpm
Signs: hypoxia, silent chest, poor respiratory effort, bradycardia or hypotension, exhaustion, confusion, coma

Question 10

What is the management of acute severe asthma?

Answer 10

Oxygen
Corticosteroids
Nebulised bronchodilators
Ventilation

Discharge when PEF<25%
Support, safety, education, personalised asthma action plan, follow up