Asthma Flashcards
What is asthma
Chronic inflammation of the airways, hyper responsive airways
What are the symptoms of asthma
Dyspnoea, cough, wheeze
What happens to smooth muscle and airway membranes in asthma?
Smooth muscle hypertrophy
Thickening and disruption of airway membrane
Risk factors for asthma
Family history of atopy (maternal atopy most influential), male sex (asthma development), female sex (asthma persistence into adulthood), premature/low birth weight, smoking, obesity, occupational dusts
What triggers childhood asthma
Usually a URTI
What is genetic involvement in asthma
30-80%
What signs/symptoms in history indicate asthma
Wheeze, cough, dyspnoea, episodic diurnal symptoms
Common triggers, occupation, family history, smoking history
On examination what may you find
May be normal between exacerbations
Increased work of breathing, cyanosis, cough
What are side effects of salbutamol use
Fine tremor
Side effect of inhaled corticosteroids inhaler
Oral candidiasis
Reduced height if given to children
What WOULDN’T you find in asthma
Nail clubbing, stridor, asymmetrical chest expansions, creps
What variability in twice daily PEFR suggests asthma (over 2wks)
20%
What are you looking for in blood tests for asthma
CRP and white blood cell count to rule out infection
High eosinophil found and total IgE suggestive for asthma
What would you expect to see on CXR of asthma
Typically Normal - may show Hyperinflation
Important for ruling out differential diagnosis
What would you expect to see in spirometry of asthma
FEV1/FVC <70% (obstructive pattern)
Reversibility testing with bronchodilator
What exhaled nitric oxide would you expect to see in asthma
High FeNO
How to decipher between COPD and asthma
pulmonary function test (DLCO)
Lungs ability to diffuse carbon monoxide
- decreased in COPD
- normal or increased in asthma
What is the stepped approach in asthma
Low dose ICS (brown inhaler) +/- SABA when necessary (blue inhaler) —> add LABA (green inhaler) —> increase ICS or add oral LTRA
What is first line of treatment for asthma in <5y.o.
LTRA
Criteria for moderate asthma attack and treatment
able to speak HR below 110 respiratory rate below 25 PEFR 50-75% PO2 and sats OK reduced PCO2
Treatment = treat trigger and administer inhaler/oral steroid
Criteria and treatment for severe asthma attack
any one of:
- inability to complete sentences in one breath
- HR above110
- respiratory rate above 25
- PEFR 33-50%
- PO2 and sats OK
- reduced PCO2
admit, nebulise, IV hydrocortisone three times a day, oral prednisolone once a day
Criteria of life threatening asthma
any one of:
- arrhythmia, grunting, impaired consciousness,
confusion, exhaustion, bradycardia, hypotension, cyanosis, silent chest, poor respiratory effect,
- PEFR below 33%
- sats below 92%
- PO2 below 8kPA
- normal PCO2 (4.6-6.0kPa)
Criteria and treatment of near fatal asthma
Near fatal asthma attack > raised PCO2
mechanical ventilation necessary
Treatment of asthma attacks
oxygen if sats below 94% —> nebulised salbutamol —> hydrocortisone/oral prednisolone —> nebulised ipratropium bromide (muscarinic antagonist) —> one dose magnesium sulphate
How to treat >5s with suspected asthma
2 month ICS followed by inhaler holiday around Easter time to rule out false positives
this trial may reduce final adult height by 0.5-1cm
How to assess paediatric asthma control
S = SABA/per week, more than twice indicates poor control A = absence from school/nursery N = nocturnal symptoms E = exacerbation symptoms
Benefits of spacers
Increase delivery 4 fold
When should dry powder not be used
<8y.o or low dexterity
