asthma and airways disease Flashcards
what is the most common respiratory disease
asthma
what is the epidemiology of asthma
- high prevelance in UK, america, australlia
- lower prevelance in lower income countries e.g. ethiopia has a prevelance of 2%
what are the tisk factors of asthma
- family history
- age (peak prevelance around 6-12)
- presence of other allergic/ atopic conditions
- social deprivation
- smoking
- air pollution
what is the 3 pathological basis of asthma
- increased airway obstruction
- airway inflammation
- bronchial hyper reactivity
what is the most common type of asthma
-type 2 eosinophilic asthma (common in adults, allergic asthma common in children)
what are the triggers for asthma
- indoor sensitisation (house dust mite, moulds)
- outdoor sensitisation (tree pollen, grass pollen)
- viral infections
- air poullatants
- medications (aspirin)
- sulfites in food stuff
what are the symptoms of asthma
- coughing
- shortness of breath
- weezing
- recurrant chest infections
can depend on season
how does a peak flow diary work and what are the adv and disadv
- measure expiratory flow and keep a diary this could be over a few days or a few weeks etc
- more than 20% variabiltiy suggestive of asthma
- adv includes cheap, easy, repeatable
- disadv include need forced exhalation so effort dependant, not specific to asthma, patients need to keep track
how does spirometery work
- measures flow volume and prodcues a flow volume loop
- adv allows to calculate fev1, fev1/fvc ratio, definitive test for airway obstruction and reversibility
- diadv include patient needs to do trest during exacerbation and normal test does not exclude asthma
what is the FeNO test
- biomarker
- NO is a biomarker for eosinophilic inflammation
- diadv elevated in other conditions such as rhinitis, just a measurment of a specific inflammation
what is the bronchial challenge
- inhalation of metacholine (or manittol) and the concentration required to cause 20% fall in fev1 is measured
- adv measure airway hyperresponsivness
- disadv may not be tolerated by some, time consuming, cannot be done on everyone
what can inhaled asthma medications be classified into
- short and long acting beta agoonists
- long and short acting muscarinic antagonists
- inhaled corticosteroids
what is an example of a short acting beta agonsit for asthma
salbutamol
what is an example of a long acting beta agonist for asthma
- salmetarol
what is an example of a short acting muscarinic antagonist for asthma
- ipratropium
what is an example of a long acting muscarinic antagonist for asthma
- tiotropium
what is an example of an inhaled corticosteroid for asthma
- beclomethasone
how can the oral asthma medications be divided into
- oral corticosteorids
- leukotriene receptor antagonist (blocks production of leukotrienes)
- theophylines (cause bronchodilation via several mechanism
what is an example of a leukotriene receptor antagonists for oral asthma medication
montelukast- blocks production of leukotrienes
what is an example of a theophylines- oral medication of asthma
- aminophylinne
what is an example of a oral corticosteroid for asthma
- prednisolone- reduce inflammation by altering production if inflammatory mediators
what is an example of anti IgE injectible asthma medication
- omalizumab
what is an example of an anti IL5 injectible asthma medication
- mepolizumab/benralzumab
what is an example of an anti IL4 injectible asthma medication
duplimubab
what is an example of an anti thymic storm lymphopoitin (TSLP) for asthma
- tezepelumab (inhibits antigen presentation)
what are the three types of inhalers
- pMDI
- dry mist inhaler
- soft mist inhaler
what is the disadvantage of dry mist inhaler
- need full inhalation force (quick and deep breaths in)
- can be diffficult for children, elderly, suring severe asthma attacks
what is the issue with pMDIs
- works by using hydrofluorocarbon propellant
- HCFs are powerful greenhouse gases
- contrubute to 3-4% CO2 footprint of NHS
should all patients be on dry mist inhaler
- no as not all patients woulndt be able to take quick and deep inahlation to use a DPI
- some patients (mainly with COPD) lack rthe necessary inspiratory flow to use a DPI
how can asthma be classified
- moderate asthma (PEF>50-75%)
- acute severe asthma (PEF 33-50%
- life threatening asthma (PEF<33%)
What are signs of moderate asthma
- PEF 50-75%
- SpO2> 92%
- no features of acute severe asthma
what are the signs of acute severe asthma
- 33-50% PEF
- SpO2>92%
- cannot complete sentance in one breath
- respiration >25/min
what are the signs of life threatening asthma
- PEF <33%
- siltent chest, cyanosis, poor respirtory effort
- exhaustion, altered consciousness
- arryhthmias, hypotensions
- SpO2>92%
what is MART
- maintenance and reliever therapy
- taken daily and during exacerbations/acute onsets
- includes ICS, LABA used as both maintenance and reliever
- seperate reliever salbutamol not required
what is AIR
- anti inflammatory reliever
- combinated of ICS and LABA, only taken when patient has symptoms
what are the risk factors of COPD
- tobacco smoking
- environmental exposures such as biomass feul exposure and air pollution
what are the symptoms of copd
- breathlessness
- wheezing
- chronic cough/ sputum production
- recurrant respiratory tract infections
what two conditons come under COPD
- chronic bronchitis (persistent airway inflammation and mucus hypersecretion)
- emphysema (desturction of alveolar sacs leading to impaired gas exchange, also adds to airway obstruction by changing the sturucture of the lung surrounding the bronchioles
what is the key patholgoy in COPD
- airflow obsturction
- gas trapping and hyperinflation
- impaired gas exchange and ventilation/perfusion mismatch
- pulmonary hypertension (due to hypoxia leading to vasoconstriction)
- exacerbations
- increased comorbitidies
hwat test do you need to do to diagnose someone with COPD
- spirometery to measure airflow obstruction
what values can we dereive from spirometry for COPD
- FEV1
- FVC
- PEAK FLOW
- FEV1/FVC ratio
what is the most cost effective way of treating COPD
- flu vaccines
- followed by stop smoking suport with pharmocotherapy
- most expensive is triple therapy
what is pulmonary rehabilitation
- pulmonary rehabilitation is a specialised programe of exercise and education designed to help people with lungs problems such as COPD
- peopl with stable COPD and a score of 3 or above on the MRC dyspnoea are reffered to pulmonry rehabilitation
treating COPD exarcerbations
- Short acting bronchodilators
- oral corticosteorids
- antibiotics
- ventilaiton support
