Asthma Clinical Features in Adults Flashcards
What is asthma?
A disease characterised by an increased responsiveness of the trachea and bronchi to various stimuli and manifested by a widespread narrowing of airways that change in severity either spontaeously or a result of therapy
What is an important indicator of asthma, in terms of symptoms?
Variability of symptoms
What does asthma result in?
Widespread narrowing of the airways
What percentage of children have asthma?
10-15%
What percentage of adults have asthma?
5-10%
Are most children with asthma male or female?
Male
Are most adults with asthma male or female?
Female
How many people in the UK are recieving asthma treatment?
5.4 million
How many children in the UK are recieving asthma treatment?
1.1 million
How many adults in the UK are recieving asthma treatment?
4.3 million
How often does somebody have a life threatening asthma attack?
Every 10 seconds
What kinds of everyday things are totally or very limited by asthma?
Running
Sport
Stairs
Pets
DIY
Gardening
Pub
Waling
Sleeping
How many admissions of asthma are there a year?
67,000
How many bed days per year does asthma use?
220,000
How many GP consulations are about asthma?
4.1 million
What is the total cost of asthma to the NHS?
£889 million
What is the total cost of asthma to the economy, due to productivity and benefits?
£1460 million
What is the total cost of asthma to the economy and the NHS?
£2.349 billion
How many working days a year are lost due to asthma?
12.7 million days
How has asthma prevalence changes over the last 60 years?
Increased massively until about 2010 when it began to drop
What are some proven risk factors for asthma?
Genetics
Occupation
Smoking
What is atopy?
Inherited tendency to IgE response to allergens
If your mother has asthma how much more at risk are you than if your father had it?
3x
How much of adult onset asthma is due to occupation?
Underestimated at 10-15%
What kinds of things are people exposed to at work that leads to asthma?
Isocyanates (paint)
Colophony (welding)
Laboratory animals
Grains
Enzymes
Drugs
Crustaceans (shell fish)
What effect does maternal smoking during pregnancy have on the babies breathing?
Decreases FEV1
Increases wheezy illness
Increases airway responsiveness
Increases asthma
Increases severity
What is the ‘grandmother effect’?
If your grandmother smoked you are more at risk of asthma
What are some possible risk factors of asthma?
Obesity
Diet
Reduced exposure to microbes
Indoor pollution (chemical household products)
What kind of things in someones diet increases the risk of asthma?
Less antioxidants
Less n-3 polyunsaturated fatty acids
More n-6 polyunsaturated fatty acids
More and less vitamin D
Why do we know reduced exposure to microbes might increase the risk of asthma?
Children born on farms are less likely to develop asthma
How do we know indoor pollution might increase the risk of asthma?
Cleaners are more at risk of developing asthma
What are some environmental allergens linked to asthma?
House dust mite
Cat
Grass pollen
What is it important to remember about the link between allergens and asthma?
Exposure to allergens does not cause atopy or asthma, but factors associated with affluence increase the likelihood of sensitisation to local allergens
What are some things that might cause localised airway obstruction?
Inspiratory stridor
Tumour
Forign body
What are some things that might cause generalised airway obstruction?
Asthma
COPD
Bronchiectasis
Bronchiolitis
Cystic fibrosis
What is most important for making the asthma diagnosis?
History, examination is rarely useful
What are some symptoms of asthma?
Wheeze
Short of breath
Chest tightness (pain)
Cough, usually dry
Sputum (occasionally)
What does an asthma sufferer bringing up green spit mean?
Not always an infection, neutrophils and polymorphs from inflammation also cause this
What are some different things that could trigger asthma?
Exercise
Cold air
Smoke
Perfume
Pets
Trees
Grass pollen
Food
Asparin
When may symptoms vary?
At different times, there could be:
Daily variations (nocturnal/morning)
Weekly variations (occupation, better at weekends)
Annual variations (environmental allergens)
What does asthma often show during an examination?
Breathless on exersion
Hyperexpanded chest
Polyphronic wheeze
What if seen on examination suggests it is not asthma?
Clubbing, cervical lymphadenopathy
Stridor
Asymmetrical expansion
Dull percussion note (lobar collapse, effusion)
Crepitation (bronchiectasis, CF, alveolitis, LVF)
What is crepitation?
A crackling sound
What does it mean if the examination is normal?
It fits with asthma
What does it mean if the examination is abnormal?
It does not fit with asthma
What are we looking for in investigations to prove it is asthma?
Airway obstruction
Variability and/or reversibility of airway obstruction
What is the first investigation we do for asthma?
FEV1 testing (spirometry)
What do we do if spirometry testing for FEV1 is normal?
Test variability of airflow obstruction using a peak flow meter and chart twice daily for two weeks
Variability suggests asthma
If the FEV1 testing is normal, how often and for how long is a peak flow meter used to test variability of airflow obstruction?
Twice daily for 2 weeks
What do we do if the spirometry testing FEV1 shows obstruction?
1) Full pulmonary testing
2) Reversibility to bronchodilator
3) Reversibility to corticosteroids
What does full pulmonary testing exclude?
COPD/emphysema
Increase gas transfer suggests asthma, decreased suggests COPD
When does full pulmonary testing suggest asthma?
If increase gas transfer
What is the process of testing reversibility to bronchodilator?
1) Take baseline measurement
2) Give salbutamol
3) Compare the difference
When does testing the reversibility to bronchodilator suggest asthma?
Increase in FEV1 after salbutamol suggests asthma, no increase suggests COPD
How much of an increase suggests asthma when testing reversibility to bronchodilator?
More than 12%
When testing reversibility to oral corticosteroids, what suggests asthma?
Improvement suggests reversibility so asthma, no improvement suggests COPD
What is the FEV1/FVC ratio for an airway obstruction?
Less than 70%
What might suggest occupational asthma?
Suspicion from work related symptoms
Working with recognised occupational sensitiser
How is occupational asthma confirmed?
Serial peak flow readings, 2 hourly best for 2 days minimum
Difference in and out of work shows occupational asthma
What are examples of specialised investigations?
Airway responsiveness to methacholine/histamine
Exhaled nitric oxide
What are some additional useful investigations?
Chest x-ray
Skin prick testing
Total and specific IgE
Full blood count
What could a chest x-ray of someone with asthma show?
Hyperinflated, hyperlucent
No effusion, collapse, opacities, interstitial changes
What does skin prick testing, total and specific IgE and full blood count test?
Atopic status
Why is being objective more important than subjective?
Life threatening asthma may not induce any visible distress
What physiological indicators are checked when dealing with asthma?
Ability to speak
Heart rate
Respiratory rate
PEF
Oxygen saturation/arterial blood gases
What is acute asthma?
Flare up of asthma
What are the different kinds of acute asthma?
Mild
Severe
Life threatening
Near fatal
What are the physiological values for mild asthma?
Able to speak, complete sentances
Heart rare < 110
RR < 25
PEF 50-75%
SaO2 > 92%
PaO2 > 8kPa
What are the physiological values for severe asthma?
Unable to speak, unable to complete sentences
HR > 110
RR >25
PEF 33-50%
SaO2 > 92%
PaO2 > 8kPa
What are the physiological values for life threatening asthma?
Grunting
Impaired consciousness, exhaustion
HR > 130 or bradycardiac
Hypoventilating
PEF < 33%
Cyanosis
SaO2 < 92%
PaO2 < 8kPa
PaCO2 normal (4.6 - 6kPa)
What physiological value is for near fatal asthma?
Raised PaCO2
What does near fatal asthma require?
Mechanical ventilation
What is bradycardia?
Slower heartrate than normal
What is cyanosis?
Discolourisation to the skin
