FN: Chronic Asthma

Question 1

Definition

Answer 1

Episodic, reversible airway obstruction due to bronchial hyper-reactivity to a variety of stimuli

Question 2

Epi

Answer 2

incidence 5-8%

Peaks at 5 yrs, most outgrow by adolesence

Question 3

Acute pathophysiology

Answer 3

1. Mast cell-Ag interaction –> histamine release

2 Bronchoconstriction, mucus plugs, muscosal swelling

Question 4

Chronic pathophysiology

Answer 4

1. Th2 release IL-3,4,5 –> mast cell, eosinophil and B cell recruitment
2. Airway remodelling

Question 5

Causes

Answer 5

Atopy
Stress
Toxins

Question 6

Atopy

Answer 6

T1 hypersensitivity to a variety of antigens

Dust mites, pollen, food, animals, fungus

Question 7

stress

Answer 7

cold air
Viral URTI
Excercise
Emotion

Question 8

Toxins

Answer 8

Smoking, pollution, factory

Drugs: NSAIDS, Beta-blockers

Question 9

Symptoms

Answer 9

Cough ± sputum (often at night)
Wheeze
Dyspnoea
Diurnal variation with morning dipping

Question 10

History

Answer 10

Precipitants
Diurnal variation
Excercise tolerance
Life effects: sleep, work
Other atopy: hay fever, eczema
Home and job environment

Question 11

Signs

Answer 11

1. Tachypnoea, tachycardia
2. Widespread polyphonic wheeze
3. Hyperinflated chest
4. reduced air entry
5. Signs of steroid use

Question 12

Associated Disease

Answer 12

1. GORD
2. Churg-stauss
3. ABPA

Question 13

Differential

Answer 13

1. Pulmonary oedema (cardiac asthma)

2. COPD

Question 14

Investigations

Answer 14

Bloods
CXR
Spirometry
PEFR monitoring/diary
Atopy

Question 15

Bloods show

Answer 15

FBC - eosinophilia
raised IgE
Aspergillus serology

Question 16

CXR shows

Answer 16

Hyperinflation

Question 17

Spirometry

Answer 17

Obstructive pattern with FEV1:FVC 15% improvement in FEV1 with Beta agonist

Question 18

PEFR monitoring.diary

Answer 18

Diurnal variation >20%

Morning dipping

Question 19

Atopy

Answer 19

Skin-prick

RAST

Question 20

General MEasures:TAME

Answer 20

Technique for inhaler use
Avoidance: allergens, smoking, dust
Monitor: Peak flow diary (2-4 x/d)
Educate

Question 21

Education

Answer 21

Liaise with specialist nurse
Need for treatment compliance
Emergency action plan

Question 22

Drug ladder

Answer 22

1. SABA PRN
2. Low-dose inhaled steroid: beclometasone
3. LABA: salmeterol 50 ugbd + steroid _ Leukotriene
4. Trials of increased inhaled steroids, Leukotriene receptor antagonist, SR theophylline, MR agonist PO
5. Oral steroids

Question 23

Step 1

Answer 23

SABA but if using>1/d or nocte symptoms move to step 2

Question 24

Step 2

Answer 24

Low-dose inhaled steroid: beclometasone 100-400ug bd

Question 25

Step 3

Answer 25

LABA: salmeterol 50ug bd

1. Good response continue
2. Benefit but control still poor: increase steriod to 400ug bd
3. No benefit: discontinue + raise steroid to 400ug bd

If control is still poor consider trial of:

a. Leukotriene receptor antagonist (e.g. montelukast) - especially if excercise/NSAID-induced asthma
b. SR theophylline

Question 26

Step 4

Answer 26

Trials of:

1. increased inhaled steroid to up to 1000ug bd
2. Leukotriend receptor antagonist
3. SR theophylline
4. MR beta agonist PO

Question 27

Step 5

Answer 27

Oral steroids e.g. prednisolone 5-10mg od

1. Use lowest dose necessary for symptom control
2. Maintain high-dose inhaled steroid
3. Refer to asthma clinic