Asthma Flashcards
What are the types of airway diseases?
obstructive
- hard to exhale all the air in the lungs
= asthma, COPD, cystic fibrosis, bronchiecstasis
restrictive
- difficulty expanding the lungs with air
= pulmonary fibrosis, sarcoidosis, pneumonia
What is asthma? What are the different types?
chronic obstructive inflammatory disease of the airways
- characterised by reversible airway obstruction and bronchospasm/bronchoconstriction
occupational asthma, pet asthma, exercise induced asthma, aspirin sensitive asthma
What is the pathophysiology of asthma?
airway inflammation
- eosinophils, mast cells
= exaggerated IgE mediated response causes hypersensitivity
airway hyper-responsiveness
- resulting in airway smooth muscle contraction
airway obstruction
- caused by airway hyper-responsiveness and mucus excess
narrowing of airways causes reduced gas flow and oxygen exchange resulting in ventilation perfusion mismatch
- if chronic airway remodelling and fixed changes can occur
What causes asthma?
genetics
- is polygenic
immunology
- allergy = IgE mediated inflammation
environment
- cold, occupational, household exposure
pharmacological
- beta blocker, NSAIDs, aspirin, cholinergic agents
What are the symptoms of asthma?
cough with sputum
- worse at night and early morning (often nocturnal)
chest tightness
shortness of breath (dyspnoea) and fast breathing (tachypnoea)
wheeze
seasonal or daily variation
reduced exercise tolerance
What are the signs of asthma?
examination may be completely normal if not having an attack
expiratory wheeze
- bilateral and polyphonic (high pitched whistling noise affecting both sides of the lungs)
hyperinflation of the chest
- chest deformity and hyper resonant percussion suggesting air/fluid in the lungs
silent chest
- is life threatening
What tests can be done to diagnose asthma?
peak flow diary
- shows breathing pattern over time
spirometry
- shows presence of obstructive pattern if FEV1 < 80% and FEV1/FVC < 70%
- can be done using a bronchodilator to check if the asthma is reversible
FeNO
- measures lung inflammation
bloods
- eosinophil levels
chest X-ray
skin prick test
What are non-pharmacological treatments for asthma?
avoiding triggers
smoking cessation
What is complete control of asthma defined as?
no daytime symptoms
no night time waking due to asthma
no need for rescue medicine
no asthma attacks
no limitations on activities
normal lung function
minimal side effects
What are the steps in asthma treatment?
reliever - SABA
regular preventer - low dose inhaled corticosteroid
initial add on therapy - add inhaled LABA to low dose ICS
= either fixed dose or MART
additional controller therapies - consider either increasing ICS to medium dose or adding LTRA with or without LABA
specialist therapies
What are the types of SABAs? How do they work? What are the indications and adverse effects?
short acting beta agonists
- salbutamol, terbutaline
= cause smooth muscle dilation and bronchodilation via adenylate cyclase pathway activation
indication
- hyperkalaemia and reversible airway obstruction
adverse effects
- hypokalaemia, tremor, palpitations, tachycardia, arrhythmias, headaches, hyperglycaemia, ketoacidosis, hypotension, insomnia
What are the types of ICS? How do they work? What are the contraindication and cautions? What are the adverse effects?
inhaled corticosteroid
- beclomethasone
contraindication
- live vaccinations
cautions
- diabetes, hypertension, injection, peptic ulcer disease
adverse effects
- systemic = paradoxical bronchospasm, adrenal crisis, bruising, candidiasis, Cushing’s, hyperglycaemia, osteoporosis, stunt growth
- local = oral thrush, sore throat
What are the types of LABAs? How do they work? What are the adverse effects?
long acting beta agonists
- salmeterol, formoterol
= cause smooth muscle dilation and bronchodilation via adenylate cyclase pathway activation
adverse effects
- hypokalaemia, tremor, tachycardia, palpitations, arrhythmias, headaches, hyperglycaemia
What are the types of LABAs? How do they work? What are the adverse effects?
long acting beta agonists
- salmeterol, formoterol
= cause smooth muscle dilation and bronchodilation via adenylate cyclase pathway activation
adverse effects
- hypokalaemia, tremor, tachycardia, palpitations, arrhythmias, headaches, hyperglycaemia
What are the types of LTRAs? How do they work? What are the adverse effects?
leukotriene receptor antagonists
- montelukast
= reduces bronchoconstriction caused by leukotriene and results in less inflammation
adverse effects
- abdominal pain, thirst, headache, hyperkinesia (in children)
