Asthma: Diagnosis And Treatment

Question 1

What is asthma?

Answer 1

• Chronic inflammatory disorder in susceptible individuals

- Often reversible (unlike COPD) either spontaneously or with treatment (bronchodilator)

Question 2

What is asthma’s pathogenesis?

Answer 2

• Inflammation
• Mast cells (release inflammatory mediators)
• Eosinophil inflammation (COPD is neutrophil until exacerbation)
• Mucus plugs
• Increased airway tone
• Airway remodelling (if poorly controlled over number of years)

Question 3

How is asthma diagnosed?

Answer 3

No single diagnostic test:

• Medical history (eczema + hayfever commonly seen)
• Symptoms
• Lung function tests (spirometry and peak expiratory flow/PEF [not used for COPD])

Question 4

What are the symptoms of asthma?

Answer 4

• Wheezing/coughing
• Chest tightening
• Shortness of breath
• Commonly seen in childhood
• Triggered by allergens/exercise

Question 5

What are the 2 phases of bronchoconstriction?

Answer 5

• Immediate phase (bronchospasm w/wheezing)

- Late phase - 3-4 hours later (further inflammation and airway obstruction, cough + sputum production)

Question 6

What are the aims of asthma treatment?

Answer 6

• No daytime symptoms
• No night time wakening due to asthma
• No need for rescue medication/reliever (preventing asthma attacks)
• No exacerbations
• No limitations on activity (inc. exercise)
• Normal lung function
• Minimal side effects

Question 7

What is the asthma treatment plan/ladder?

Answer 7

1. ) SABA (as required)
2. ) Add ICS (if having to use SABA more than 3x a week/wake in night from asthma)
3. ) LABA (if no response stop LABA and increase ICS to 800 mcg a day)
4. ) Theophylinne/ICS dosage to 2000 mcg
5. ) Oral steroid (daily) at lowest dose maintaining ICS 2000mcg, refer to specialist

Question 8

Why is stepping down asthma treatment important?

Answer 8

Risks of over treatment:

• Well documented in asthma
• Increases risk of adverse outcomes
• Increasing use of combination inhalers keeps patients at Step 3 or above

Marginal additional benefit for higher steroid doses; eliminate risk of long-term adverse events/side effects by titrating dose down (5mg at a time usually)

Question 9

What is omalizumab’s mode of action and when is it used?

Answer 9

• Monoclonal antibody binding to IgE

- Add-on to optimise therapy where severe persistent allergic asthma is seen

Question 10

What is defined as a moderate acute asthma exacerbation?

Answer 10

• Able to talk
• Pulse 110 BPM
• Peak flow >50% predicted/best

Question 11

How is a moderate acute asthma exacerbation treated?

Answer 11

Treat at home or in surgery (and assess response)
- SABA w/spacer or use nebuliser
(spacer counters poor coordination where nebulisers are more commonly seen in hospital)
- Prednisolone (oral steroid) 40-50mg for 3 to 5 days (higher dose than COPD [30mg] but shorter course)

Send to hospital if response poor.

Question 12

What is defined as a severe asthma exacerbation?

Answer 12

• Cannot complete sentence in 1 breath
• Respiration > 25 breaths a min
• Pulse > 100 BPM
• Peak flow 33-55% predicted/best

Question 13

How is a severe acute asthma exacerbation treated?

Answer 13

Start treatment and send to hospital immediately:

• Ipraptropium bromide
• High flow oxygen
• SABA via spacer/nebuliser
• Prednisolone oral as per moderate OR IV hydrocortisone

Consider: IV beta-2 agonist/aminophylline/magnesium sulfate (monitor plasma level)

Question 14

What is defined as a life threatening asthma exacerbation?

Answer 14

• Silent chest/feeble respiratory effect
• Hypotension/bradycardia (slow)/arrhythmias/reduced consciousness
• Peak flow

Question 15

How is a life threatening acute asthma exacerbation treated?

Answer 15

The same as severe.