Asthma Flashcards
is asthma an acute or chronic inflammatory condition of the airways
chronic
asthma is associated with the hyper responsiveness of the airways and variable flow obstruction, bronchial hyperreactvity is a key feature and results in what?
asthmatic response based on particular triggers
exposure to triggers causes constriction of airway smooth muscle which results in
bronchoconstriction
bronchoconstriction is a result of the activation of x nervous system
parasympathetic
bronchoconstriction causes the release of ach which activates the x receptors in airway smooth muscle
m3 muscarinic
what is consequence of activation of m3 muscarinic receptors
contraction of smooth muscles and constriction of diameter airway
inflammation results in the production of x and y in the airway
excess mucus and oedema
the combination of bronchoconstriction and inflammation results in the classic symptoms of asthma which are
breathlessness
cough
wheeze
frequency and severity of asthma symptoms can vary between the same person and among different people but often has diurnal variation, what is meant by this
increased symptoms at night and first thing in morning
asthma is diagnosed from an accurate clinical history which is used in conjunction with
objective diagnostic test
what is the purpose/ benefit of doing an objective diagnostic test for asthma diagnosis
provide evidence and allow for monitoring of progress and response to treatment
what different things should a clinical history check for
wheeze
cough breathlessness
variation in symptoms
triggers
personal or family history of atopic disorders
what procedure to listen for wheeze is an important part of the physical examination done alongside clinical history
chest auscultation
name some other objective tests that are used to investigate asthma
feno
spirometry
peak flow
FeNO (fractional exhaled nitric oxide) is a relatively new test, what does it measure and provide an indication of
measures level of no in exhaled breath and provides indication of eosinophilic inflammation in the lungs
name a test that can be used to facilitate an asthma diagnosis so that patients do not have to be referred to secondary care for additional testing such as spirometry
FeNO
a feno level above x ppb is considered to be a positive test and therefore supports a diagnosis of asthma
40
name a test that can be used to look for eosinophilic inflammation in the lungs
feno
what rr would you expect to see in acute severe asthma
equal or more than 25 breaths/min
what pulse rate would you expect to see in acute severe asthma
equal or more than 110 beats/min
list some life threatening features of acute severe asthma
ox below 92
silent chest
cyanosis
poor resp effort
arrythmia
hypotension
exhaustion
step 1 is regular preventor: low dose ICS, whats next?
add on
inhaled LABA
step 2 additional controller therapies - consider what?
increasing ICS to med dose
or
add LTRA
… if no response to LABA, stop
CHECK INHALER TECHNIQUE
ICS
combination
SABA
LAMA
when asthma control is poor patients should be stepped up but what should be checked before this
adherence
inhaler technique
potential triggers
name some identified triggers for asthma
allergens: moulds, pollen
infectious agents: influenza
drugs: nsaids, bb, prostaglandins
occupational: latex
hair colourants
other: cold air
stress
A patient is complaining of shortness of breath, what should you ask about in the clinical history to see if asthma is a possible differential diagnosis?
Clinical history should check for:
wheeze, cough or breathlessness and any daily or seasonal variation in these symptoms
any triggers that make symptoms worse
a personal or family history of atopic disorders
When (and why) is magnesium used in the management of asthma?
in severe cases as adjunct to standard therapy as it has been shown to cause bronchial smooth muscle relaxation
what route is magnesium given in asthma? severe
10-20min IV infusion
why might magnesium be beneficial in acute asthma compared to a drug like theophylline
safe and inexpensive
