asthma Flashcards
what is asthma?
heterogenous disease characterised by chronic airway inflammation with variable airflow obstruction
what causes the airflow obstruction? 3
- bronchoconstriction= contraction of the smooth muscle in the bronchial wall
- bronchial secretions and plugs of mucus= due to inflammation of the bronchial wall
- oedema of the bronchial wall= due to inflammation of the lining mucosa in the bronchial wall
describe asthma and atopy? 3
- asthma in young people is generally linked to atopy
- tendency to form IgE antibodies to allergens
- often associated hay fever of eczema in the personal and family history
what are the symptoms of asthma? 6
- cough
- wheeze
- breathlessness
- chest tightness
- occurs in episodes with periods of minimal symptoms
- diurnal variability so worse at night or early morning
what medications can trigger asthma? 3
- aspirin
- ibuprofen
- beta blockers
how do we diagnose asthma? 5
- history is critical, need more than one symptom
- symptom free periods
- past medical history, family history, social history
- alternative diagnosis- what else could this be?
- physical examination may be normal except during an attack
how do investigate asthma? 3
- GP= peak flow 2x a day for 2 weeks or spirometry
- GP/hospital= CXR, increased blood eosinophils, fraction exhaled nitric oxide
- hospital= skin prick or blood test
describe a lung function test ? 3
- is there an airflow obstruction? FEV1/FVC ration <70
- does it vary over time? peak flow monitoring- 20% diurnal variation
- is it reversible? with bronchodilators, 15% improvement
what is fractional exhaled nitric oxide? 4
- measure of airways eosinophilic inflammation
- performed on patients not on any treatment, positive test supports diagnosis of asthma
- GP of hospital clinics
- used to monitor treatment and look at compliance
how do we manage asthma? 5
- smoking cessation
- weight reduction
- pollution may provoke acute asthma or aggravate existing asthma, but effects from allergens, smoking and infection are more significant
- inhaled corticosteroids
- inhaled long acting beta 2 agonists (in combination with ICS)
what are the long term pharmacological treatments? 3
- oral leukotriene antagonist- montelukast
- oral theophylline
- low dose long term oral steroids
what is maintenance and reliever therapy? 5
- 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 doses for short periods to rapidly treat any worsening asthma symptoms
- aim to address and treat the inflammatory aspect of the disease by having both ICS and LABA
what are the 2 different types of inhalers?
- dry powder- activated by inspiration of the patient, drug is dispersed into particles by the inspiration
- pressurised metered dose inhalers- drug dissolved in propellant hydrofluorocarbons under pressure valve system, which releases a metered dose
how do we pick which inhaler to prescribe? 6
- what treatment are they on
- what device can they use
- side effects
- what do they want to use
- counter so they know how many doses are left
- cost
what are the 3 key questions to ask an asthma patient?
- have you had any difficulty sleeping because of your symptoms
- have you had your usual asthma symptoms during the day
- has your asthma interfered with your usual activities
describe monoclonal antibody treatment? 3
- anti-IgE injections
- anti IL-5 treatment
- bronchial thermoplasty
what is done on a personal asthma action plan? 6
- daily medication to take and why
- which triggers to avoid
- signs of asthma deterioration
- names and doses of treatment for worsening asthma
- indicators of how and when to seek medical attention
- 2-3 action point
what are the features of severe asthma? 6
- PEFR <33%
- SpO2 <92%
- silent chest, feeble respiratory effort
- arrhythmia or hypotension
- exhaustion
- > 110 HR
how do we manage severe asthma? 5
- oxygen
- corticosteroids
- nebulised bronchodilators
- if poor response, then intravenous MgSO4
- exceptionally intubation and ventilation
when do we discharge asthma patients from the hospital? 7
- been on discharge medication for 24 hours
- inhaler technique checked
- PEFR >75% of best
- treatment with oral and inhaled steroids in addition to bronchodilators
- own peak flow metre
- GP follow up after 2 days
- respiratory clinic follow up in 4 weeks