Asthma

Question 1

what is asthma

Answer 1

chronic, inflammatory airway disease. characterised by reversible airway obstruction, airway hyper-responsiveness and bronchial inflammation

Question 2

aetiology

Answer 2

genetic factors and environmental factors

Question 3

genetic factors causing asthma

Answer 3

family Hx and atopy

Question 4

what is atopy

Answer 4

genetic tendency to develop allergic diseases such as allergic rhinitis, asthma and atopic dermatitis (eczema). this is a tendency of T cells to drive the production of IgE cells upon exposure to allergens

Question 5

environmental factors causing asthma

Answer 5

house dust mites, pollen, pets, cigarette smoke, viral respiratory tract infections, aspergillus fumigatus spores (fungal infection) and occupational allergens

Question 6

epidemiology

Answer 6

10% of adults affected, 5% of children affected.

prevalence is increasing

Question 7

presenting symptoms

Answer 7

recent upper respiratory tract infection, dyspnoea, cough, expiratory wheeze and nasal polyposis (nasal polyps)

Question 8

why may GORD be a risk factor for asthma

Answer 8

aspiration of particles may cause an upper respiratory tract infection

Question 9

is the cough better in the morning or at night

Answer 9

cough in asthmatics is usually worse in the mornings and improves as the day goes along

Question 10

precipitating factors

Answer 10

Cold  
Viral infection  
Drugs (e.g. beta-blockers, NSAIDs) 
Exercise  
Emotions

Question 11

signs on physical examination

Answer 11

tachypnoea, patient uses accessory muscles to aid breathing, prolonged expiratory phase, polyphonic wheeze, hyper inflated chest

Question 12

pulmonary function tests on severe attack

Answer 12

PEFR < 50% predicted
Pulse > 110/min
RR > 25/min
Inability to complete sentences

Question 13

pulmonary function tests on life-threatening attack

Answer 13

PEFR < 33% predicted  
Silent chest  
Cyanosis  
Bradycardia  
Hypotension  
Confusion  
Coma

Question 14

investigations in the acute setting

Answer 14

peak flow, 
pulse oximetry, ABG, CXR, FBC,
CRP, 
Urea and Electrolytes,
Blood and sputum cultures

Question 15

investigations in the chronic setting

Answer 15

Peak flow monitoring - often shows diurnal variation with a dip in the morning
Pulmonary function test
Bloods - check:
Eosinophilia
IgE level
Aspergillus antibody titres
Skin prick tests - helps identify allergens

Question 16

management (acute exacerbation)

Answer 16

ABCDE
Resuscitate
Monitor O2 sats, ABG and PEFR
High-flow oxygen
Salbutamol nebulizer (5 mg, initially continuously, then 2-4 hourly)
Ipratropium bromide (0.5 mg QDS)
Steroid therapy
100-200 mg IV hydrocortisone
Followed by, 40 mg oral prednisolone for 5-7 days
If no improvement –> IV magnesium sulphate
Consider IV aminophylline infusion
Consider IV salbutamol
Anaesthetic help may be needed if the patient is getting exhausted

Question 17

why is normal pCO2 not a good sign

Answer 17

a patient in an asthma attack should be hyperventilating to get rid of the CO2 so a normal pCO2 indicates a deteriorating patient

Question 18

Step 1 of chronic asthma management

Answer 18

Inhaled short-acting beta-2 agonist used as needed

If needed > 1/day then move onto step 2

Question 19

step 2 of chronic asthma management

Answer 19

Step 1 + regular inhaled low-dose steroids (400 mcg/day)

Question 20

step 3 of chronic asthma management

Answer 20

Step 2 + inhaled long-acting beta-2 agonist (LABA)
If inadequate control with LABA, increase steroid dose (800 mcg/day)
If no response to LABA, stop LABA and increase steroid dose (800 mcg/day)

Question 21

step 4 of chronic asthma management

Answer 21

Increase inhaled steroid dose (2000 mcg/day)

Add 4th drug (e.g. leukotriene antagonist, slow-release theophylline or beta-2 agonist tablet)

Question 22

step 5 of chronic asthma management

Answer 22

Add regular oral steroids
Maintain high-dose oral steroids
Refer to specialist care

Question 23

advice given to all asthmatic patients

Answer 23

teach proper inhaler techniques,

explain the importance of PEFR monitoring,

avoid provoking factors

Question 24

possible complications of asthma

Answer 24

Growth retardation,

Chest wall deformity (e.g. pigeon chest),

Recurrent infections,

Pneumothorax,

Respiratory failure,

Death

Question 25

prognosis in children

Answer 25

many children improve as they grow older

Question 26

prognosis in adults

Answer 26

adult-onset asthma usually remains chronic