Asthma Clinical Features in Adults 2 Flashcards
What can a spirometer be used to measure
How much air can be expelled
Are the spirometery results reproduceable
Yes
Will a spirometer exclude asthma
No
What do FEV1 levels measure
Airway diameter
What does the FVC measure
Lung volume and can identify changes in lung tissue
What are the FEV1 and FVC levels like in asthma
Normal
What should be done if spirometery is normal
Peak flow monitoring
Bronchial provocation with nitric oxide
What should be done if the spirometery shows obstructed disease
Full pulmonary function test
How can the reversibility of an obstructed disease be tested
Through the use of a beta 2 agonist or steriods
What does it mean if the FEV1/FVC is below 70% and FEV1 is below 80% predicted
Obstructed disease
What will the full pulmonary testing effectively exclude
COPD
Emphysema
What does gas trapping measure and what is used
Helium dilution to measure lung volumes
What will the results of gas trapping show in obstructed disease
The residual volume increases
The total lung capacity increases
RV/TLC is over 30%
Will gas transfer be normal or abnormal in asthma
Normal
How can gas transfer be measured
Carbon monoxide gas transfer
What to tests are used in full pulmonary function testing
Gas trapping
Gas transfer
When should the response to the bronchodilator be at the baseline
15 minutes post 400 microgram inhaled salbutamol
15 minutes post nebuliser 2.5-5mg salbutamol
Which results show that significant reversibility is possible
If delta-FEV1 is over 200ml and delta-FEV1 is over 15% of the baseline
When is the use of oral corticosteriods useful
In obstructed disease - it will help determine reversibility and variability
What 2 diseases can oral corticosteriods seperate
COPD from asthma
Why should the variability in airflow obstruction be looked for in asthmatic patients
Their lung function may be normal in clinic
How can the variability in airflow obstruction be identified
Through the use of a peak flow meter and chart twice daily for 2 weeks
What may the results of a peak flow meter for asthmatic patients show
Morning/nocturnal dips
Decline over weeks/days
Variability over 20% ([highest-lowest]/highest)
What 2 things can cause occupational asthma to be suspected
Work related symptoms
Working with recognised sensitisers
How is occupational asthma diagnosed
From serial peak flow readings that are done every 2 hours for a minimum of 5 days
Must be at least 2 pairs of exposed/unexposed periods
Antibodies and bronchial challenges can also confirm this
Name an optional investigation which can be conducted
Testing of the airway responsiveness to methacholine/histamine/mannitol/exercise
What other tests can be useful in identifying asthma
Chest X-ray - may show hyperinflation and hyperlucent
Skin prick testing - identifies atopic status
Total and specific IgE - identifies atopic status
Full blood count - may show eosinophilia (atopy)
What are the 5 main things that should be tested in life threatening asthma
Ability to speak Heart rate Respiratory rate PEF Oxygen saturation/Arterial blood gases
Should a pulsus paradoxus be conducted in life threatening asthma
No
How will moderate asthma present
Able to speak complete sentences HR <110 RR <25 PEF 50 - 75% predicted or best SaO2 > 92% (no need for ABG) PaO2 > 8kPa
How will severe asthma present
Unable to speak, unable to complete sentences HR >110 RR >25 PEF 33 - 50% predicted or best SaO2 > 92% PaO2 > 8kPa
How will life threatening asthma present
Grunting Impaired consciousness, confusion, exhaustion HR >130, or bradycardic Hypoventilating PEF < 33% predicted or best Cyanosis SaO2 < 92% PaO2 < 8kPa PaCO2 normal (4.6 - 6.0kPa)
How will near fatal asthma present
Raised PaCO2
