Asthma

Question 1

Definition of asthma

Answer 1

Chronic inflammatory airways disease characterised by a) variable reversible airways obstruction b) airway hyper-responsiveness and c) bronchial inflammation

Question 2

Key inflammatory mediators in asthma

Answer 2

Mast cells (with surface IgE) and histamine cause bronchoconstriction, oedema, mucus hypersecretion
Longer term- granulocytes/lymphocytes cause inflammation leading to airway remodelling

Question 3

Features which suggest a severe asthma attack (2)

Answer 3

PEFR 33-50% of expected

Inability to complete sentences

Question 4

Features which suggest a life-threatening asthma attack (3)

Answer 4

PEFR less than 33% of expected
Silent chest
Cyanosis

Question 5

Important differentials for acute asthma attack (4)

Answer 5

In children- bronchiolitis (RSV)
Foreign body inhalation
Anaphylaxis
Acute exacerbation of COPD

Question 6

What is an indication that the patient is becoming exhausted?

Answer 6

Rising CO2 (CO2 is initially low due to hyperventilation)

Question 7

Managment of acute asthma (5)

Answer 7

Oxygen
Nebulised salbutamol
Nebulised ipratropium
Oral prednisolone
IV magnesium sulphate injection

Question 8

What add-on therapies are available? (4)

Answer 8

Leukotriene antagonist
Theoophylline
Beta-2 agonist tablet
Long-acting muscarinic antagonist

Question 9

First-step management of adult asthma? (2)

Answer 9

Low-dose ICS + salbutamol PRN

Question 10

What threshold determines whether to “move up” a step in the management algorithm?

Answer 10

Using SABA (e.g. salbutamol) more than 3 times a week

Question 11

First step treatment failure, what next?

Answer 11

LABA (e.g. salmeterol) + ICS combination inhaler

Question 12

If LABA/ICS combo fails to control symptoms what should be the next step?

Answer 12

Depends on whether response to LABA: if no, stop LABA and increase ICS dose. If yes, continue LABA and increase ICS to medium dose

Question 13

Features which suggest life-threatening asthma?

a) PEFR
b) Sats
c) Chest signs
d) Heart signs
e) “Brain” signs

Answer 13

a) PEFR < 33% best or predicted
b) o2 sats < 92%
c) Chest: Silent chest/cyanosis/poor effort
d) Heart: Bradycardia/dysrhythmia/hypotension
e) Brain: Exhaustion, confusion, coma

Question 14

In suspected occupational asthma what investigation is indicated?

Answer 14

Serial peak flow measurements at work and away from work

Question 15

What is Samter’s triad?

Answer 15

Asthma, nasal polyps, aspirin intolerance

Question 16

When does exercise-induced asthma tend to get worse?

Answer 16

5-10 minutes after exercise

Question 17

How does theophylline work?

Answer 17

Phosphodiesterase inhibitor; helps potentiate cyclic AMP and result in airway dilatation

Question 18

How can NSAIDs cause exacerbations?

Answer 18

Enhance production of leukotrienes which are potent bronchoconstrictors

Question 19

What has been shown to be an effective treatment in patients with acute asthma who do not respond to initial steroid and nebuliser therapy?

Answer 19

Single dose Mg sulphate IV