what is asthma?
- heterogenous disease characterised by chronic airways inflammation
- variable airflow obstruction
what is the WHO definition of asthma?
it is a disease characterised by recurrent attacks of breathlessness and wheezing which vary in severity and frequency form person to person. In an individual, there may occur form hour to hour and day to day
what causes airflow obstruction?
- bronchoconstriction = contraction of the smooth muscle in the bronchial wall
- bronchial secretions and plugs of mucus = due to inflammation of bronchial wall
- oedema of the bronchial wall = due to inflammation the lining mucosa in the bronchial wall
what is ATOPY?
- asthma in young people is linked to atopy
- tendency to form IgE antibodies to allergens
- often associated hay fever or eczema in the person or family history
what are the symptoms of asthma?
- cough
- wheeze
- breathlessness
- chest tightness
- occurs in episodes
what is diurnal variability?
worse at night or early morning
what are the medication triggers of asthma?
- aspirin
- ibuprofen
- beta blockers
how do you make the diagnosis of asthma?
- history is critical need more than one symptom
- symptom free periods
- past medical history, family history, social history
- alternative diagnosis?
- physical examination may be normal except during an attack
what investigations are done for asthma?
- tests done by GP = peak flow twice a day for 2 weeks or spirometry
- tests done by GP/hospital = chest x-ray, increased eosinophils in blood, fraction exhaled nitric oxide
- tests done by hospital = skin prick or blood test
what questions do you ask with the lung function test?
- is there an airflow obstruction?
- does it vary over time?
- is it reversible?
what is FeNO - faction of exhaled nitric oxide?
- measure of airways eosinophilic inflammation
- performed on patients not on any treatment, a positive test supports diagnosis of asthma
- can be done in GPs and hospital clinics
- can be used to monitor treatment/look at compliance
how do you manage asthma?
- smoking cessation
- weight reduction
- pollution may provoke acute asthma or aggravate existing asthma but effects from allergens, smoking and infection more significant
- inhaled corticosteroids
- inhaled long acting beta 2 agonists in combination with ICS
what are the long term oral treatments for asthma?
- oral leukotriene antagonists, montelukast
- oral theophyllines
- low dose long term oral steroids
what is maintenance and reliever therapy (MART)?
- LABA formoterol has short onset of action
- equivalent of salbutamol
- so certain specific ICS/LABA combinations can be used as relievers as well as preventers
- so patients can take additional does for short periods to rapidly treat any worsening asthma symptoms
- aim to address and treat the inflammatory aspect of disease by having both ICS and LABA
what questions do they ask to choose an inhaler?
- what treatment are they on?
- what device can they use?
- side effects
- what do they want to use?
- counter so know how many doses left
- cost
what are the 3 key asthma questions?
- have any difficulty sleeping because of your asthma symptoms?
- has you had your usual asthma symptoms during the day?
- has your asthma interfered with your usual activities?
what are the very specialised asthma treatments?
- anti-IgE injections
- anti IL-5 treatment
- bronchial thermoplasty
what are the 2 types of inhalers?
- dry powder inhalers
- pressurised metered dose inhalers
what do you write on the personal asthma action plan (PAAP)?
- list daily medication
- list which asthma triggers to avoid and importance of smoke free environment
- list what to look for signs of deterioration of asthma
- list names and doses of medication to be taken to treat worsening asthma
- list indications of how and when to seek medical attention
- easy to understand, 2-3 action points, traffic light colour coded
what are the features of acute severe athma?
- peak expiratory flow rate, 33-50% of best
- breathless
- respirations >25 breaths/min
- pulse >110 beats/min
what are life threatening features of asthma?
- PEFR <33%
- SpO2 <92%
- silent chest, cyanosis, feeble respiratory effort
- arrhythmia or hypotension
- exhaustion, altered consciousness
how do you manage severe asthma?
- oxygen
- corticosteroids
- nebulised bronchodilators
- is poor response intravenous MgSO4
- exceptionally intubation and ventilation
how do you know when do discharge and asthmatic from hosptial?
- been on discharge medication of 24 hours
- inhaler technique checked and recorded
- PEFR >75% of best or predicted and PEFR diurnal variability <25%
- treatment with oral and inhaled steroids in addition to bronchodilators
- own peak flow metre and written PAAP
- GP/nurse follow up within 2 working days
- follow up appointment in respiratory clinic within 4 weeks
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mechanisms of breathing, pressures & work29
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measuring lung function17
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gas exchange & gas transport21
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arterial blood gas32
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respiratory failure33
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oxygen therapy & sleep apnoea44
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asthma23
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respiratory infection42
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imaging the thorax19
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COPD27
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clinical consequences of respiratory infection21
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tuberculosis25
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HIV & respiratory infections11
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interstitial lung diseases30
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pleural & chest wall diseases30
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respiratory pharmacology49
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cough & breathlessness10
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lung cancer12
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occupational lung disease25
