Case 2 - Asthma - Progress Test Revision

Question 1

What type of reaction is asthma?

Answer 1

Type 1 hypersensitivity

Question 2

What immune cell is over active in asthma?

Answer 2

IgE

Question 3

Risk factors for asthma

Answer 3

Personal / family history of atopy. 
Antenatal factors: maternal smoking, viral infection during preganacy (especially RSV). 
Low birth weight. 
Not being breastfed. 
Maternal smoking around child. 
Exposure to high concentrations of allergens. 
Air pollution. 
Hygiene hypothesis.

Question 4

Related IgE conditions

Answer 4

Atopic dermatitis (eczema). 
Allergic rhinitis (hay fever)

Question 5

What medication are some patients with asthma sensitive to?

Answer 5

Aspirin

Question 6

What are some examples of occupational triggers for asthma?

Answer 6

Isocyanates (eg. spray painting, foam moulding using adhesives)
Flour

Question 7

What time of day is an asthmatic cough often worst?

Answer 7

Night

Question 8

What are the signs of asthma

Answer 8

Expiratory wheeze on auscultation.

Reduced PEFR.

Question 9

Spirometry results in asthma

Answer 9

FEV1  = significantly reduced 
FVC = normal 
FEV1/FVC = < 70%

Question 10

What other tests can be used to diagnose asthma?

Answer 10

Fractional exhaled nitric oxide

shows level of inflammation

Question 11

What is the 1st line medication for asthma?

Answer 11

SABA (eg. salbutamol)

Question 12

What are side effects of a SABA?

Answer 12

Tremor

Question 13

2nd line medication for asthma?

Answer 13

SABA + ICS (eg. beclamethasone, dipropionate, fluticason, propionate)

Question 14

What are side effects of ICS?

Answer 14

Oral candidiasis

Stunted growth in children

Question 15

4th line medication for asthma?

Answer 15

SABA + ICS + LABA (eg. salmeterol) +/- LTRA

Question 16

3rd line medication for asthma?

Answer 16

SABA + ICS + Leukotriene receptor antagonist (eg. monteleukast) PO

Question 17

What medications are in a MART inhaler?

Answer 17

ICS + LABA

Question 18

5th line medication for asthma

Answer 18

SABA +/- LTRA + MART

Question 19

What is a positive FeNO result for asthma?

Answer 19

> 40 parts per billion

Question 20

What is a postive spirometry result for asthma?

Answer 20

< 70%

obstructive

Question 21

What is a positive reversibility testing result for asthma?

Answer 21

Improvement in FEV1 of >= 12%
+
Increase in volume of >= 200ml

Question 22

What is classified as moderate acute asthma?

Answer 22

PEFR 50-75% best or predicted

Speech normal

RR < 25 / min

Pulse < 110 bpm

Question 23

What is classified as severe acute asthma?

Answer 23

PEFR 33-50% best or predicted

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RR > 25 / min

Pulse > 110 bpm

Question 24

What is classified as life-threatening asthma?

Answer 24

PEFR < 33% best or predicted

O2 sats < 92%

Normal pCO2 (exhaustion)

Silent chest, cyanosis or feeble respiratory effort

Bradycardia, dysrhythmia or hypotension

Exhaustion, confusion or coma

Question 25

Who should be admitted to hospital in acute asthma?

Answer 25

All patients with life-threatening asthma Patients with severe asthma who don't respond to initial treatment Patients with a previous near fatal attack Pregnant patients An attack in patients on oral corticosteroids Patients presenting at night

Question 26

What is the management of acute asthma?

Answer 26

O2 - 15L non-rebreathe SABA (eg. salbutamol / terbutaline) Oral prednisolone 40-50mg - for at least 5 days or until recovered Ipratropium bromide IV magnesium sulphate IV aminophylline (requires senior consultation) Referal to ITU/HDU for intubation and ventilation / ECMO

Question 27

What is the criteria for discharge after acute asthma?

Answer 27

Stable on discharge medication for 12 - 24 hrs Inhaler technique checked and recorded PEF > 75% best or predicted

Question 28

What are the stages of asthma pathogenesis?

Answer 28

- Sensitisation - Early phase reaction - Late phase reaction

Question 29

What happens during the sensitisation stage of asthma pathogenesis?

Answer 29

- Exposure to inhaled allergen. - Stimulates induction of Th2 cells. - Th2 cells secrete cytokines and stimulate B cells to produce IgE. - The cytokines induce IL-4 (which increases IgE production), IL-5 (which activates eosinophils) and IL-3 (which activates mucus secretion). - IgE coats mast cells and repeated allergen exposure triggers mast cells to release granule contents and produce cytokines

Question 30

What is involved in the early phase reaction of asthma?

Answer 30

- Bronchoconstriction. - Increased mucus production. - Variable degrees of vasodilation with increased vascular permeability.

Question 31

What is involved in the late phase reaction in asthma

Answer 31

- Inflammation. - Chemokine release from mast cells, epithelial cells and T cells. - Recruitment of leucocytes (especially eosinophils, neutrophils and T cells).

Question 32

What enzyme does aspirin block, causing it to be a trigger in asthma?

Answer 32

Cyclo-oxygenase | reducing production of prostaglandins

Question 33

What is the pharmacology of SABA / LABA

Answer 33

Agonists of B2 adenoceptors on bronchiole smooth muscle - causing relaxation

Question 34

What is the pharmacology of theophylline?

Answer 34

- Phosphodiesterase (PDE) inhibitor (triggers activation of PKA and muscle relaxation). - Adenosine receptor antagonist.

Question 35

What is the pharmacology of ipratropium?

Answer 35

- Muscarinic receptor antagonist. | muscarinic receptors are triggered in asthma by binding of ACh, causing smooth muscle contraction

Question 36

What is the pharmacology of monteleukast?

Answer 36

- Leukotriene receptor antagonist. - Prevents activation of the leukotriene receptor (which causes broncoconstriction) and promotes production of prostaglandins (which cause bronchodilation). - Act at cysteinyl-leukotriene receptors on bronchiole smooth muscle cells preventing action of LTC4 and LTD4 (which cause bronchial spasm and stimulate mucus secretion)

Question 37

What is the pharmacology of glucocorticoids?

Answer 37

Reduce production of cytokines, spasmogens (LTC4 and LTD4) and leucocyte chemotaxins (LTB4, PAF). - Hence reduced bronchospasm and recruitment and activation of inflammatory cells

Question 38

What receptors do glucocorticoids bind to?

Answer 38

GR alpha and GR beta Causing induction of lipocortin and repression of IL-3