ASTHMA

Question 1

WHAT IS THE PATHOPHYSIOLOGY OF ASTHMA?

Answer 1

• Chronic inflammatory disease of airways leading to reversible airflow obstruction
• Airway narrowing caused by:
  1) Bronchoconstriction - histamine release from mast cells
  2) Mucosal oedema- mucus hypersecretion forms mucous plug
  3) Airway hyper-responsiveness- exaggerated narrowing response to stimuli

Question 2

WHAT ARE THE TRIGGERS FOR ASTHMA?

Answer 2

• cold weather
• allergens- pollen, pets (ask about atopic symptoms such as eczema and hay fever)
• smoking
• exercise

Question 3

WHAT ARE THE SYMPTOMS OF ASTHMA?

Answer 3

1) cough - worse at night + early morning
2) intermittent dyspnoea
3) expiratory wheeze
4) sputum
5) tight chest

Question 4

WHAT ARE THE INVESTIGATIONS FOR ASTHMA?

Answer 4

1) Spirometry- obstructive/ FEV1:FVC<70%
2) Bronchodilator reversibility- give salbutamol and improvement in FEV1 is positive test
3) Peak expiratory flow

Question 5

WHAT ARE THE DIFFERENTIAL DIAGNOSIS FOR ASTHMA?

Answer 5

• COPD
• Heart failure
• Large airway obstruction (foreign body)
• Pulmonary oedema

Question 6

WHAT ARE THE LIFESTYLE MANAGEMENT FOR ASTHMA?

Answer 6

1) Smoking cessation
2) Avoid triggers
3) Education of relaxed breathing

Question 7

WHAT IS THE PHARMCOLOGICAL MANAGEMENT OF ASTHMA?

Answer 7

• Step- wise approach to treatment, step up when worse and step down when there is good control of asthma (no daytime symptoms, no night-time awakening, no asthma attacks.
  1) STEP 1 - SABA (salbutamol) for symptom relief. Move step 2 if using SABA more than once daily/ night time symptoms
  2) STEP 2 - low dose ICS (beclomethasone) for maintenance/ preventer therapy
  3) STEP 3 - SABA+ low dose ICS + LTRA (Montelukast)
  4) STEP 4 - SABA + low dose ICS + LABA, continue LTRA depending on patients response
  5) STEP 5 - SABA +/- LTRA, switch ICS/LABA for maintenance and reliever therapy (MART) that includes low dose ICS. Refer to asthma clinic

Question 8

WHAT ARE THE FEATURES OF AN ACUTE SEVERE ASTHMA ATTACK?

Answer 8

1) can’t complete sentences in 1 breath
2) SPO2 < 92%
3) PEFR - 33-50% best or predicted
4) HR > 110 bpm
5) RR > 25 bpm

Question 9

WHAT IS THE MANAGEMENT OF ACUTE SEVERE ASTHMA ATTACK?

Answer 9

1) Controlled supplementary oxygen via face mask- SPO2 94-98%
2) Nebulised high dose salbutamol (5mg) - repeat after 15 min
3) Oral prednisolone/ IV hydrocortisone (40mg)
4) Nebulised ipratropium bromide (500 microgram)
5) IV theophylline

OSHIT

Question 10

WHAT ARE THE FEATURES OF LIFE THREATENING ASTHMA ATTACK?

Answer 10

1) silent chest
2) SPO2 <92% / ABG PaO2 < 8kpa
3) cyanosis
4) feeble respiratory effort
5) coma
6) confusion

Question 11

WHAT IS THE MANAGEMENT FOR LIFE THREATENING ASTHMA ATTACK?

Answer 11

1) ITU referral

2) IV aminophylline

Question 12

WHAT ARE THE FEATURES OF MODERATE ASTHMA ATTACK?

Answer 12

1) increasing symptoms
2) peak flow > 50-75% best or predicted
3) no features of acute severe asthma

Question 13

WHAT ARE THE FEATURES OF NEAR FATAL ASTHMA ATTACK?

Answer 13

1) raised PaCO2 and/ or need for mechanical ventilation with raised inflation pressure

Question 14

WHAT IS ACUTE MILD ASTHMA?

Answer 14

Symptoms up to 2 days per week or 2 nights per month