Asthma – an overview

Definition of asthma
Diagnosis and natural history. Thorax 2003; 58 (Suppl I): i1-i92
“A Chronic Inflammatory Disorder of the airways … in susceptible individuals, inflammatory symptoms are usually associated with widespread but variable airflow obstruction and an increase in airway response to a variety of stimuli.
Obstruction is often Reversible, either spontaneously or with treatment.”

Adam and Eve
and
Christopher Robin

Eve is a 5-year old girl with:
Personal and family history of allergy
Wheeze on laughing and exercise
Severe attacks with colds
Bronchodilator-responsive and dependent on inhaled
corticosteroid
Persistent symptoms and PEF variability on a
depressed baseline
Evidence of allergy
Eosinophilic airway inflammation
Evidence of allergy
Eosinophil airway inflammation

Adam is a 14-month old boy with:
A single, smoking non-allergic mother Multiple admissions to hospital with viral, episodic wheeze
Poor response to nebulised ß agonist
No symptoms between episodes
No evidence of allergy
No inflammation between episodes

What is
“Wheeze”?

wall compliance
cross sectional
area
dissipation of energy
flutter
wheeze
Flow limitation and wheeze

How can airway narrowing be measured?

Volume, time and flow
Flow (l/sec) Time (sec)
Volume (l)

Volume, time and flow
Flow (l/sec) Time (sec)
Volume (l)

Flow-volume curves

Bronchodilator response

What’s bronchial responsiveness?
(or hyper responsiveness: BHR)

Trigger + Bronchial Airway Wheeze,
responsiveness narrowing cough &
dyspnoea

Trigger + Bronchial Airway Wheeze,
responsiveness narrowing cough &
dyspnoea
Allergy Inflammation
Infection
+
Remodelling

Trigger + Bronchial Airway Wheeze,
responsiveness narrowing cough &
dyspnoea
Allergy Inflammation
Infection
+
Remodelling

Trigger + Bronchial Airway Wheeze,
responsiveness narrowing cough &
dyspnoea
Allergy Inflammation
Infection
+
Remodelling

Triggers
Allergen (pollen, cat…)
Air pollution (smoke…)
Infection (URTI)
Exercise, etc.

Asthma history questionnaire
• age of onset of symptoms
• pattern of symptoms
• amount of disturbance to everyday life,
schooling etc.
• definite association with precipitating factors
- allergic, infective, emotional, exercise,
environmental
• family background and other illnesses
• previous treatment
- appropriateness and technique
- response

Chronic Wheeze: Non-Asthmatic
Cystic fibrosis (host-defence)
Bronchiectasis
Foreign body aspiration
Congenital airway disease
Recurrent aspiration syndrome
other!!

British Guideline on the Management of Asthma
A national clinical guideline
Thorax 2003; 58 (Suppl I): i1-i92
The British Thoracic Society Scottish Intercollegiate Guidelines Network

Asthma control
Pharmacological management. Thorax 2003; 58 (Suppl I): i1-i92

Pharmacological management. Thorax 2003; 58 (Suppl I): i1-i92
Stepwise management of
asthma in adults

Summary
• outline of asthma
• fill in the details
British Guidelines
British Thoracic Society
• pharmacology of drugs

Any
questions?