1. ProfessorProfessor
Abdur-Rab KhanAbdur-Rab Khan
MRCP- FRCP (UK)MRCP- FRCP (UK)
Ayub Medical College AbbottabadAyub Medical College Abbottabad

2. Diagnosis of AsthmaDiagnosis of Asthma

3. HistoryHistory

5. Peak Expiratory Flow RatePeak Expiratory Flow Rate
(PEFR)(PEFR)
 Measures how fast a person can exhale air
 Requires a peak expiratory flow monitor
OmronMini-Wright AM2 Plus

6. PEFR VariabilityPEFR Variability
Asthma Diagnostic Clues:
• PEF Variability > 20%
(basis: home monitoring 2-4x/day
for 1-2 weeks)
• Improvement in baseline PEF by
20% after a 2-week therapeutic
trial
PEFmax - PEFmin
PEFave
(pm, post-bd) (am, pre-bd)
% Variability = X 100
0
50
100
150
200
250
300
350
1 2 3 4 5 6 7
Days
PEFR(L/min)
pm PEFR
am PEFR

10. SpirometrySpirometry
 Recommended for the initial assessment of all
asthma suspects!

13. > 15% increase in FEV1.0
after ß-2 inhalation
Hallmark of Asthma: Reversibility!
Spirometry

15. Types of Flow
Volume Curves
Normal Obstructive
Litersper
second
Concavity
Asthma
Concavity
pre-
bronchodilator
Improved
post-bronchodilator

16. Good MeasurementsGood Measurements
are Essential!are Essential!
Acceptable
Loop
Unacceptable
Loop

17. Is it Asthma?
Determine that the patient is
experiencing episodic symptoms
of airflow obstruction
Demonstrate that the
obstruction is at least partially
reversible
Exclude alternate diagnoses

18. Asthma
wheezing
Lung Disease Overlap
Chronic
Bronchitis
cough+sputum
Emphysema
breathlessness
Airway Remodeling in
Asthma
Denudation of the airway
epithelium
Collagen deposition
beneath the basement
membrane
Edema
Mast cell activation
Inflammatory cell
infiltration
COPD

19. Classifying Severity:
BASED ON SYMPTOMS & LUNG FUNCTION
Daytime
Symptoms
Exacerbations Night
attacks
11
22
33
44
IntermittentIntermittent
• <1x a week • Brief
MildMild
persistentpersistent
• >1x a week
but < 1x/day
• May affect
activity &
sleep
ModerateModerate
persistentpersistent
• Daily • May affect
activity &
sleep
SevereSevere
persistentpersistent
• < 2x a
month
• > 2x a
month
• > once
a week
• Frequent• Daily • Frequent
• Limits
physical
activity
FEV1 or PEF
• > 80% predicted
• Variability < 20%
• > 80% predicted
• Variability 20-30%
• > 60-80%
predicted
• Variability > 30%
• < 60% predicted
• Variability > 30%

20. THANK YOUTHANK YOU