diagnosis

1
diagnosis
Asthma
2
Asthma Diagnosis

• History and pattern of symptoms
• Physical examination
• Measurements of lung function
• -Reversibility test
• -Diurnal variability
• Evaluation of allergic status

3
Is it asthma?

• Symptoms - variable in time and severity
• Cough
• Wheeze
• Breathlessness
• Chest tightness
• Symptoms occur or worsen at night or after
  exposure to trigger
• Colds go to chest or take more than 10 days to
  clear

4
Asthma in children

• In addition to typical symptoms
• coughing at night or following exercise
• repeated chest infections / wheezy bronchitis
• reluctance to take part in physical activities
  including sport and exercise

5
Ask about triggers
Symptoms can occur or worsen in the presence of

• Allergens
• Animals with fur
• Domestic dust mites
• Pollen
• Fungi

• Others
• Exercise
• Viral infection
• Smoke
• Changes in temperature
• Strong emotional expression
• Aerosol chemicals
• Drugs (NSAIDs, ß-blockers)

6
Reversible and variable airflow limitation

• Reversibility of airways obstruction
• Increased PEF gt 15 15-20 minutes after inhaling
  ß2 agonist
• Variability of airways obstruction
• PEF varies between morning and evening
• gt 20 in patients taking bronchodilator
• gt 10 in patients not taking bronchodilator
• Exercise-induced airways obstruction
• Decreased PEF gt 15 after 6 minutes of exercise

GINA Guidelines 1998
7
Peak Flow Measurement
8
Importance of long termpeak flow measurements

• To establish diagnosis and treatment
• To assess severity of an exacerbation
• To assess response to treatment
• To evaluate how well controlled asthma is
• To alert patient to need for possible change in
  treatment

9
PEF curves
Epidemiology/pathology
PEF (litres/minute)
Before bronchodilator
After bronchodilator
Day Number
Morning M
Evening E
10
Exacerbation
PEF
Mild attack
Acute severe attack
exacerbation
Days
11
FEV1 measurement
12
FEV1 curves
Volume
FEV1
Normal Subject
Asthmatic (After Bronchodilator)
Asthmatic (Before Bronchodilator)
1
2
3
4
5
Time (sec)
Note Each FEV1 curve represents the highest of
three repeat measurements
13
Skin Prick Test
14
Diagnostic challenges in adults

• Heart failure
• COPD
• Angina
• Bronchiectasis
• Lung cancer

15
Diagnostic challenges in children

• Croup
• Bronchitis / pneumonia
• Inhaled foreign body
• Cystic fibrosis
• Heart failure

16
Classification of Severity
Clinical Features Before Treatment
Nighttime Symptoms
Symptoms
PEF
STEP 4 Severe Persistent
Continuous Limited physical activity
lt60 predicted Variability gt30
Frequent
STEP 3 Moderate Persistent
gt60 - lt80 predicted Variability gt30
Daily Use ?2-agonist daily Attacks affect activity
gt1 time week
STEP 2 Mild Persistent
gt1 time a week but lt1 time a day
gt80 predicted Variability 20-30
gt2 times a months
lt1 time a week Asymptomatic and normal PEF
between attacks
STEP 1 Intermittent
gt80 predicted Variability lt20
lt2 times a month
GINA Guidelines 1998