2. Asthma Flashcards
What is asthma
chronic inflammatory condition caused by hypersensitivity of the airways leading to bronchoconstriction
Name the typical triggers of asthma
infection night time or early morning exercise animals cold/damp dust strong emotions
Name some key presentations that would suggest a diagnosis of asthma
episodic symptoms
diurnal variability, typically worse at night
dry cough with wheeze and SOB
history of atopic conditions such as eczema, haha fever and food allergies
family history
Bilateral widespread “polyphonic” wheeze heard by a healthcare professional
When auscultation for asthma what would you hear which would be suggestive of asthma
Bilateral widespread “polyphonic” wheeze heard by a healthcare professional
What presentation would indicates a diagnosis other than asthma
wheeze related to coughs and colds more suggestive of a viral induced wheeze
isolated or productive cough
normal investigations
no response to treatment
unilateral wheeze, this would suggest a focal lesion or infection
what are the first line investigations fo diagnosis of asthma
fractional exhaled nitric oxide (not routine in the UK)
Spirometry with bronchodilator reversibility
what are other investigations that can be carried out for diagnosis of asthma
peak flow variability (keep a diary of peak flow measurements several times a day for 2-4 weeks)
FEV1/FVC ratio
direct bronchial challenge test with histamine or methacholine
As well as medication to treat asthma, what other additional management should patients with asthma have
an individual self-management plan
yearly flu jab
yearly asthma review
advice on exercise and avoiding smoking
What is the first line treatment for ongoing asthma
Short acting beta 2 agonist inhaler ie salbutamol as required for infrequent wheezy episode’s
add a low dose inhaled corticosteroid (such as beclametasone ), ICS if having symptoms 3 times a week or more
what other treatment options are there if the asthma isn’t controlled with a SABA and low dose corticosteroid
can use an oral leukotriene receptor antagonist such as montelukast (LTRA) and ICS
then LABA and ICS
then maintenance and deliver therapy (MART) or fixed dose of ICS and LABA and SABA as reliever therapy
how do you describe an acute exacerbation of asthma
a rapid deterioration in symptoms that could be triggered by any of the typical asthma triggers such as an infection, exercise or cold weather
how does someone with acute exacerbation of asthma present
progressively worsening SOB
use of accessory muscles
fast respiratory rate (tachypnoea)
symmetrical expiratory wheeze on auscultation
the chest can sound tight with reduced air entry
How do you grade acute asthma into moderate, severe and life threatening in terms of their PEFR
moderate- PEFR 50-75% of predicted
severe- 33-50% of predicted
life threatening- less than 33%
in addition to reduced PEFR what other things would make you grade the acute asthma as severe
resp rate above 25
heart rate above 110
unable to complete sentences
in addition to reduced PEFR what other things would make you grade the acute asthma as life threatening
becoming tired
no wheeze ie ‘silent chest’
haemodynamic instability (ie shock)
If the patient has moderate acute asthma what is the treatment
Nebulised beta-2 agonists (i.e. salbutamol 5mg repeated as often as required)
Nebulised ipratropium bromide- anti-muscarinic
Steroids. Oral prednisolone or IV hydrocortisone. These are continued for 5 days
Antibiotics if there is convincing evidence of bacterial infection
If the patient has severe acute asthma what is the treatment
- Oxygen if required to maintain sats 94-98%
- Aminophylline infusion
- Consider IV salbutamol
if the patient has life threatening acute asthma what is the treatment
- IV magnesium sulphate infusion
- Admission to HDU / ICU
- Intubation in worst cases – however this decision should be made early because it is very difficult to intubate with severe bronchoconstriction
What would the ABG look like in patients with acute asthma
respiratory alkalosis as tachypnoea causes a drop in CO2
normal pCO2 or hypoxia is concerning as shows they are tiring and indicates life threatening asthma
respiratory acidosis due to high CO2 is very bad sign in asthma
why do you need to monitor serum potassium when on salbutamol
causes potassium to be absorbed from the blood into the cells
also causes tachycardia