Asthma Diagnosis and Monitoring

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ASTHMADiagnosis and Monitoring

• Dr. S. K. Jindal
• www.jindalchest.com

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Key Issues

• Underdiagnosis / Misdiagnosis and ?
  Overdiagnosis
• Establishing diagnosis criteria
• Severity assessment / Classification
• Monitoring

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Establishing Diagnosis

1. Clinical features
2. Demonstration of airway obstruction
3. Variability and reversibility of A.O.
4. Excluding other causes of wheezing / airway
   obstruction
5. Establishing hypersensitivity
6. Assessment of reversibility
7. Demonstration of inflammation

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Clinical Features

• Symptoms Episodic
• Cough, breathlessness
• Wheezing, chest congestion
• heaviness
• Expectoration Nil to profuse
• Frothy to purulent
• Signs Hyperinflated chest
• Rhonchi, crackles
• General systemic

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Airway Obstruction

• Physical examination
• Wheezing, prolonged expiration
• Measuring forced expiratory time
• Chest roentgenography
• PEF measurement
• Spirometry ?FEV1, FEV1/VC
• Airway resistance

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Establishing variability / reversibility

• History of paroxysmal symptoms, variable physical
  findings
• Exacerbations on exercise and other trigger
  exposures
• Broncho reversibility test
• gt15 increase in FEV1 /or FVC after S (200mg)
• Bronchial hyperresponsiveness
• Airway inflammation

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Utility of amplitude mean as a discriminator of
asthma
A
B
C
Cut-offs A 12.5 B 16.5 C 20.0
Aggarwal et al, J Asthma 2002
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Excluding other causes of wheezing / A.O.

• Sputum examination
• Chest roentgenography
• Plain CXR
• CT Scanning
• Bronchoscopic examination
• Others Upper airway exam
• Spirometry

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All that wheezes isNot AsthmaandAll
asthmadoes not wheeze
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Establishing hypersensitivity

• History of other allergies past or present
• Family history of atopy
• Blood / sputum eosinophilia
• Hypersentivity skin tests
• Bronchial hyperresponsiveness
• Serum IgE estimation

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Demonstration of Inflammation

• Clinical features
• Markers of inflammation
• Direct Bronchial biopsy
• Indirect BHR
• Induced sputum
• Breath analysis

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Clinical Uses of Markers

• Differential diagnosis
• Disease severity
• Treatment response
• Research uses
• Study of kinetics

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Breath analysis

• Exhaled NO
• Volatile gases
• CO, Ethane, Pentane
• Endogenous substances
• Inflammatory Mediators
• Cytokines
• Oxidants

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Severity Assessment

• Symptoms Respir distress
• Work performance
• Mentation
• Physical exam Indices
• Pulse, R.R., BP
• Breath sounds
• Paradox (etc.)
• PEF and FEV1
• Blood gas measurement

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Monitoring

• Symptom relief / recurrence
• Acute episodes
• Treatment response
• Drug side effects
• Disease chronicity / irreversibility

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Diurnal PEF variabilityMathematical expressions

• Amplitude percent mean
• Standard deviation percent mean
• Amplitude percent maximum
• Amplitude percent minimum
• Lowest percent personal best
• Lowest percent predicted
• Maximum/minimum percent
• Amplitude percent mesor

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A hypothetical PEF rhythm in asthma
(Jindal et al, J Asthma 2002)
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Visual Analogue Scale
R 0.5255, p lt0.01
R 0.4609, p lt0.01
Gupta et al, IJCDAS 2000
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Conclusions

• PEF variability is a useful marker of asthma in
  epidemiological studies and day to day management
• Poor sensitivity in clinical diagnosis,
  population screening, assessment of severity

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