asthma - precipitating factors & treatment Flashcards
major precipitating factors of asthma attacks?
indoor allergens outdoor allergens drugs chemicals others
indoor allergens?
animals (hair / dander)
house dust mite faeces
mould / fungus
outdoor allergens?
pollen
pollutants (car exhaust)
tobacco smoke
perfumes
drugs - precipitating factors?
NSADS & ß-blockers
chemical precipitating factors?
isocyanates, acid anhydrides (varnish / paint)
other precipitating factors?
exercise
cold air
emotional distress
principle treatments of asthma?
oxygen
salbutamol nebulisers & atrovent nebulisers
how do you administer nebulisers?
one after the other (salbutamol & atrovent) until patient can breath again
what happens if airways too narrow for nebulisers?
IV access
what if nebulisers don’t work?
may need to intubate & ITU admission
what are things patient can do to prevent asthma attacks?
patient education
change pillows & bed-sheets every few years
fresh air
stop smoking
how do you decide drug treatment for asthma?
using BTS stepwise approach
what are the 2 important classes of drugs used in treatment?
bronchodilators & steroids
why are inhalers used?
to deliver drugs in aerosol form
what do steroids do?
reduce inflammation
inhibits inflammatory mediators & cells
eosinophils respond well to steroids - prevent release of leukotrienes C4 (toxic to epithelial cells - causes it to shed)
what should mild intermittent asthma be treated with?
inhaled short acting ß2-agonist (blue) as required e.g. salbutamol
acute treatment
SAßA
when should you decide to take a step up from SAßA?
when the patient uses it more than 3 times a week or has nocturnal symptoms
what is the regular preventer therapy? (step up from SAßA)
inhaled steroids (brown inhaler)
what is the initial add-on therapy after SAßA?
LAßA (long acting ß2-agonist) - green inhaler
what is LAßA not used for?
acute
what is patient still has persistent poor control?
increase inhaled steroids
add 4th drug e.g. ß2-agonist tablet
what if increasing inhaled steroids still doesn’t work? (step 5)
continuous / frequent use of oral steroids
use daily tablet (lowest dose required for adequate control)
refer patient for specialist care
what is always important to assess patients for features of?
acute severe asthma
requires immediate treatment & hospitalisation
how do you treat acute severe asthma?
nebulised ß2-agonist and ipratropium (steroids) in delivered oxygen
and IV steroids + short course of high dose oral prednisolone (steroid)
what other drugs may be required in acute severe asthma?
magnesium sulphate & aminophylline
what do patients with features of life threatening asthma require?
ITU & ventilation
how do you diagnose asthma?
full history - ask about symptoms
PMH: eczema, hayfever
FH: atopy, smoking
SH: mould in home, farm, wood burning fire, pets
DH: medications making it worse? NSAIDS, ß-blockers
