Asthma Flashcards
(23 cards)
what is asthma
chronic inflammatory disorder of the airways, secondary to type 1 hypersensitivity, that causes episodic bronchospasm resulting in airway obstruction
risk factors for developing asthma
atopy
family history of atopy / asthma
maternal smoking during pregnancy / smoking around child
symptoms of asthma
SOB
dry cough - worse at night
wheeze
signs of asthma on examination
expiratory wheeze on auscultation
reduced Peak flow
what things can trigger symptoms of asthma
exercise stress animal dander dust infections cold air
what is spirometry
measures the amount (volume) and speed (flow) of air during inhalation and exhalation
differentiates disorders as
- obstructive: e.g. asthma where there is obstruction of airflow due to bronchoconstriction
- restrictive: e.g. fibrosis where there is restriction of the lung
what is
- FEV1
- FVC
FEV1 = forced expiratory volume (amount of air person can exhale as fast as they can in 1 second)
- reduced if any obstruction to air flow out of lungs
FVC = forced vital capacity (total amount of air person can exhale after max inhalation)
- reduced if any restriction on the capacity of the lungs
spirometry results in asthma
FEV1 - significantly reduced
FVC - normal
FEV1/FVC ratio < 70% = obstructive disease
what does the airway obstruction in asthma respond to
bronchodilators - termed ‘bronchodilator reversibility’
- will improve obstructive picture
apart from spirometry, what other tests are useful in asthma diagnosis
fractional inhaled nitrous oxide
- levels rise in correlation with eosinophilic inflammation in asthma
peak flow
1st line drug given in asthma
short acting beta 2 agonist (SABA) e.g. salbutamol
- a ‘reliever’ drug when patient experiences symptoms
common side effect of salbutamol
tremor
2nd line drug if SABA insufficient alone
SABA + Inhaled corticosteroid (ICS) e.g beclametasone
- taken everyday regardless of if patient has symptoms
- termed ‘preventer’
common side effect of ICS
oral candidiasis
stunted growth in children
3rd line drug if SABA + ICS insufficient
add oral leukotriene receptor antagonist e.g. montelukast
what further drug can be added if stage 3 therapy is not sufficient
LABA - long acting beta agonist e.g. salmeterol
what treatment can be considered in severe asthma not controlled by stage 4 regime
SABA + MART (Maintenance and reliever regime)
- ICS + LABA combination
what last resort therapies may be added before referral to specialist
oral theophylline or inhaled LAMA (long acting muscarinic antagonist e.g tiotropium)
step up treatment summary for asthma
- SABA
- SABA + ICS
- SABA + ICS + leukotriene receptor antagonist
- SABA + ICS + LABA +/- leukotriene receptor antagonist
- SABA + MART +/- leukotriene receptor antagonist
- SABA + Theophylline / tiotropium +/- leukotriene receptor antagonist
- specialist referral
features of a moderate acute asthma attack
PEFR 50-75 % of predicted
speech normal
RR < 25
features of a severe acute asthma attack
PEFR 33 - 50 % of predicted
can’t complete sentences
RR > 25
HR > 110
features of a life threatening asthma attack
PEFR < 33 % of predicted 02 sats < 92% silent chest - chest so tight there is no wheeze at all bradycardia, hypotension confusion / tiredness / coma
management of acute asthma attack
oxygen 15 L non-rebreather
nebuliser salbutamol 5mg repeated as required + nebulised ipratropium 0.5mg
oral prednisolone 40-50mg continued for 5 days
in severe cases under senior guidance
- IV magnesium sulphate
- IV aminophylline
- admission to HDU/ICU with possible need for intubation
