Asthma

Question 1

Define asthma

Answer 1

Chronic, obstructive intermittent inflammatory airway disease characterised by reversible airway obstruction, airway hyper-reactivity and bronchial inflammation

Question 2

Aetiology of asthma

Answer 2

Gene and environmental involvement.

Genetics: ADAM 33, FMHx, atopy

Environmental: Allergens, dust mite, pollen, pets, cigarette smoke, viral RTI

Question 3

Epidemiology of asthma

Answer 3

10% children, 5% adults

Prevalence increasing

Question 4

Symptoms of asthma

Answer 4

Dyspnoea
Cough: often nocturnal, worse in the morning/night 
Wheeze
Recent RTI 
Chest tightness 

Precipitating factors: cold, viral infection, drugs (beta blockers, NSAIDs), exercise, emotions

Question 5

Signs of asthma

Answer 5

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

Moderate: PEFR 50-75% best or predicted, speech normal, RR <25/min, pulse < 110bpm

Question 6

Signs of a severe acute exacerbation of asthma

Answer 6

HR >110
RR >25
PEFR 33-50%
Inability to complete sentences in one breath

Question 7

Signs of a life threatening exacerbation of asthma

Answer 7

Cyanosis (SpO2) - sats <92%
Hypotension
Exhaustion - confusion, normal pCO2
Silent chest
Tachy/brady arrhythmia

PEFR <33%

Question 8

Investigations for acute asthma exacerbation

Answer 8

Peak flow
Pulse oximetry 
ABG 
FBC, CRP, U+Es
CXR
Blood and sputum cultures

Question 9

Investigations for chronic asthma

Answer 9

Spirometry and FeNO - Ratio reduced (<0.8), FeNO ppb >40
Bronchodilator reversibility testing (BDR) - improvement of >12%
PEFR- <75% compared to normal
CXR - normal/hyperinflated
FBC - normal or raised eosinophils/neutrophils
Bronchial challenge testing - positive
Immunoassay for allergen specific IgE and Skin prick allergy testing

Question 10

What is the management for an acute exacerbation of asthma

Answer 10

1. ABCDE
2. High flow oxygen
3. Salbutamol nebs 5mg ± ipratropium 0.5mg nebs
4. IV magnesium
5. Steroids PO prednisolone 40-50mg or IV hydrocortisone 100mg
6. Specialist - aminophylline

Question 11

What is the management for an life-threatening exacerbation of asthma

Answer 11

1. ABCDE and resus
2. High flow oxygen, aim 98%
3. Salbutamol wet nebs 5mg AND iptratropium 0.5mg nebs
4. PO prednisolone 40-50mg, IV hydrocortisone 100mg
5. Ventilatory support if needed
6. IV fluids
   Consider magnesium sulfate, aminophylline, abx

Question 12

Describe the step therapy for asthma treatment in chronic disease

Answer 12

1. SABA (salbutamol 0.1-0.2mg)
2. SABA + ICS (beclomethasone 0.1-0.2mg/day)
3. SABA + ICS + LTRA (leukotriene receptor antagonist, montelukast 10mg PO 1/day)
4. SABA + ICS + LABA (+LTRA)
5. Medium dose ICS + LABA OR consider MART regimen - single inhaler of ICS and LABA e.g Fostair OR budesonide + formoterol = symbicort) OR fluticasone + salmeterol (Seretide)
6. High dose ICS + LABA
7. Trials: consider muscarinic receptor antagonist or theophylline

Question 13

What counselling should be given to asthmatic patients

Answer 13

Smoking cessation and weight loss
Trigger avoidance
Proper inhaler technique
No beta blockers or NSAIDs

Question 14

Complications of asthma

Answer 14

Severe exacerbation
Airway remodelling
Oral candidiasis secondary to ICS use 
Growth retardation in children
Chest wall deformity 
Recurrent infections
Pneumothorax
Resp. failure 
Death

Question 15

Prognosis for asthma

Answer 15

Life expectancy similar to that of the GP
Many children improve as they grow older
Adult-onset asthma is usually chronic

Question 16

When do you step up asthma therapy

Answer 16

Has an impact on lifestyle or restricts ADLs
Symptoms 3x a week or more
3x a weeks requiring SABA
1x a week awakening due to asthma