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InvestigationS
Muhammad Redzwan 081303583
FEV1 Forced Expiratory Value in 1 second.
Using spirometry
Volume of air that can forcibly be blown out in one second, after full inspiration.
Average values for FEV1 in healthy people depend mainly on sex and age.
Asthma: FEV1 ≥ 15% increase following administration of
bronchodilator/trial of CSOR
FEV1 ≥ 15% decrease after 6 minutes of exercise
PEFR Peak Expiratory Flow Rate.
Measured with a small hand held device call Peak Flow Meter.
PEF is a person's maximum speed of expiration.
Patients need to record PEF after rising in the morning and before retiring in the evening.
Asthma: >20% diurnal variation on ≥ 3 days in a week for 2 weeks
Challenge Test Sometimes patients with symptoms are suggestive of
asthma have a normal lung function.
Challenge test is done to these type of patient
Administration of sequentially increasing of concentration of either histamine, mannitol or methacholine. Adenosine challenge test is more specific
Expressed as dose of either substance needed to produce 20% decrease in the FEV1
Exercise challenge also can be done
Measurement of Allergic Status Skin prick tests can demonstrate atopy
Measurement of total and allergen-specific IgE
Full blood picture may show peripheral blood eosinophilia
Other Ix CXR is usually normal.
May shows hyperinflation of lungs fields
Lobar collapse if mucus occludes large bronchus
Flitting infiltrates if allergic bronchopulmonaryaspergillosis
Assessment of eosinophilic airway inflammation.
Sputum differential eusinophil count greater than 2% OR exhaled breath Nitric Oxide concentration
Not specific
and
Arterial Blood Gas (ABG) Important to assess severity of asthma attack
Life-threatening Features
PEF < 33% predicted (< 100 L/min)
SpO2 < 92% or PaO2 < 8 kPa
Normal or raised PaCO2 (Normal: 6 kPa)
Near fatal Asthma
Raised PaCO2 and/or requiring mechanical ventilation
Tadaaa.. Nothing here~
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