ASTHMA

Question 1

Define asthma

Answer 1

Chronic inflammatory airway disease characterised by:

• Variable reversible airway obstruction,
• Airway hyper-responsiveness and
• Bronchial inflammation

Question 2

Explain the aetiology/risk factors for asthma

Answer 2

Genetic Factors
Family history
Atopy (tendency for T lymphocytes to drive production of IgE on exposure to allergens)

Environmental Factors  House dust mites 
Pollen 
Pets  
Cigarette smoke   
Viral respiratory tract infections   
Aspergillus fumigatus spores   Occupational allergens

Question 3

Summarise the epidemiology of asthma

Answer 3

Affects 10% of children
Affects 5% of adults

Prevalence appears to be increasing

Question 4

Recognise the presenting symptoms of asthma

Answer 4

Episodic history
Wheeze
Breathlessness
Cough (worse in the morning and at night) ** BUZZ

IMPORTANT: ask about previous hospitalisation due to acute attacks -this gives an
indication of the severity of the asthma

Question 5

Precipitating Factors of asthma

Answer 5

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

(Check for history of atopic disease (e.g. allergic rhinitis, urticaria, eczema) )

Question 6

Recognise the signs of asthma on physical examination

Answer 6

Tachypnoea  
Use of accessory muscles
Prolonged expiratory phase
Polyphonic wheeze
Hyperinflated chest

Question 7

Recognise the signs of a SEVERE attack of asthma on physical examination

Answer 7

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

Question 8

Recognise the signs of a LIFE-THREATENING attack of asthma on physical examination

Answer 8

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

Question 9

Identify appropriate investigations for ACUTE asthma attack

Answer 9

Peak flow  
Pulse oximetry  
ABG   
CXR - to exclude other diagnoses (e.g. pneumonia, pneumothorax)  
FBC - raised WCC if infective exacerbation  
CRP  
U&Es  
Blood and sputum cultures

Question 10

Identify appropriate investigations for CHRONIC asthma attack

Answer 10

• 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 11

Generate a management plan for ACUTE asthma

Answer 11

• ABCDE
• Resuscitate
• Monitor O2 sats, ABG and PEFR
• High-flow oxygen
• Salbutamol nebulizer (5 mg, initially continuously, then 2M4 hourly)
• Ipratropium bromide (0.5 mg QDS) nebulizer again
•Steroid therapy
o 100M200 mg IV hydrocortisone
o Followed by, 40 mg oral prednisolone for 5M7 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
IMPORANT: a normal PCO2 is a BAD SIGN in a patient having an asthma attack This is because during an asthma attack they should be hyperventilating and blowing off their CO2, so PCO2 should be low A normal PCO2 suggests that the patient is fatiguing

Treat underlying cause (e.g. infection)
Give antibiotics if it is an infective exacerbation Monitor electrolytes closely because bronchodilators and aminophylline causes a drop in K+

Invasive ventilation may be needed in severe attacks

Question 12

When do you discharge a patient after an acute asthma attack?

Answer 12

PEF > 75% predicted
Diurnal variation < 25%
Inhaler technique checked
Stable on discharge medication for 24 hours
Patient owns a PEF meter
Patient has steroid and bronchodilator therapy
Arrange follow-up

Question 13

Generate a management plan CHRONIC asthma

Answer 13

STEP 1
Inhaled SABA, short-acting beta-2 agonist used as needed
If needed > 1/day then move onto step 2

STEP 2
Step 1 + regular inhaled low-dose steroids (400 mcg/day)

STEP 3
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)

STEP 4
Increase inhaled steroid dose (2000 mcg/day)
Add 4th drug (e.g. leukotriene antagonist, slow-release theophylline or beta- 2 agonist tablet)

STEP 5
Add regular ORAL steroids Maintain high-dose oral steroids
Refer to specialist care

Advice
Teach proper inhaler technique
Explain important of PEFR monitoring
Avoid provoking factors

Question 14

Identify the possible complications of asthma

Answer 14

Growth retardation   
Chest wall deformity (e.g. pigeon chest)   "pectus carinatum"
Recurrent infections  
Pneumothorax 
Respiratory failure  
Death

Question 15

Summarise the prognosis for patients with asthma

Answer 15

Many children improve as they grow older

Adult-onset asthma is usually chronic