Asthma Flashcards
Allergens that can be responsible for asthma attacks
cats
house dust mite
pollen
Pathological changes to airways in asthma
thickening of basement membrane
mucous gland hyperplasia
desquamation of epithelium
mucous plug formation
hypertrophy of smooth muscle
oedema of mucosa and submucosa, infiltration with eosinophils and neutrophils
Asthma symptoms
wheeze
dyspnoea
cough (may be nocturnal)
chest tightness
diurnal variation (symptoms often worse in mornings)
What is asthma associated with?
FH atopy
eczema
allergic rhinitis
nasal polyps
aspirin intolerance
What is Samter’s triad?
asthma
nasal polyps
aspirin intolerance
What can exacerbate asthma symptoms?
exercise
NSAIDs
Beta-blockers
Asthma signs
tachypnoea
hyperinflated chest
hyper-resonance on chest percussion
decreased air entry
wheeze on auscultation
Signs of severe asthma attack
inability to speak in complete sentences
respiratory rate >25
peak flow 33-50% predicted
Signs of life-threatening asthma attack
silent chest
confusion
bradycardia
cyanosis
exhaustion
Which investigations are done in chronic asthma?
peak flow - variability >20%
fractional exhaled nitric oxide (FeNO) - >40ppb in adults, >35ppb in children
spirometry - FEV1/FVC <0.7 (obstructive spirometry)
Which investigations should be ordered in an acute asthma attack?
ABG - type 2 respiratory failure (low PaO2, high PaCO2) = sign of life-threatening attack
Routine blood tests - look for precipitating cause of attack (eg. infection)
Chest xray - exclude differentials + possibly identify precipitating infection
Acute asthma attack management
ensure patent airway
ensure oxygen saturations 94-98%
nebulisers (salbutamol, ipratropium)
steroids (oral prednisolone, or if severe IV hydrocortisone)
IV magnesium sulphate if severe
IV aminophylline if severe and inadequate bronchodilatory response from nebulisers
Non-pharmacological management of chronic asthma
smoking cessation
avoidance of precipitating factors (eg. known allergens)
review inhaler technique
How can disease control be monitored?
RCP 3 questions
asthma control questionnaire (ACQ)
asthma control test (ACT)
mini-asthma quality of life questionnaire (AQLQ)
Differential diagnoses for asthma
vocal cord dysfunction (eg. paradoxical vocal cord movement)
dysfunctional breathing (eg. hyperventilation syndrome)
GORD (reflux-related cough/breathlessness)