Asthma

Question 1

Impact

Answer 1

315 million adults worldwide
340 000 deaths/year
5.4 million being treated in UK
3 people die from asthma attach each day in UK
NHS spends £1 billion each year
2017: 1484 people died in UK - 50% higher death rate than EU

Question 2

Presentation

Answer 2

Commonly presents in childhood/middle age
50% children with mild asthma will be symptom free by age 21
70% children with persistent asthma will have symptoms into adult life
If starts in adulthood - likely to persist

Question 3

Airflow Obstruction

Answer 3

Bronchoconstriction - mast cells
Bronchial secretions and plugs of mucus - inflammation
Oedema of bronchial wall - inflammation

Question 4

Inflammatory Cascade

Answer 4

Allergen -> antigen presenting cell -> Th2 -> B cell/plasma cell -> mast cell/basophil OR from Th2 -> eosinophil -> histamine -> allergic asthma

Question 5

Symptoms and Triggering Factors

Answer 5

Cough, wheeze, breathlessness, chest tightness
Occurs in episodes with diurnal variability - worse at night/early morning.
Allergens, respiratory infections
Change in temp, exercise, cold air, emotion/stress
Food additives, reflux, air pollution, tobacco
Medication: aspirin, ibuprofen, beta blockers

Question 6

Diagnosis

Answer 6

History (past medical, family, social), symptom free periods, possible alternative diagnosis (COPD)
Physical examination
Tests done: Peak flow monitoring, spirometry, chest X-ray, increased eosinophils in blood - blood test, fraction exhaled nitric oxide (FeNO)

Question 7

Fraction exhaled nitric oxide - FeNO

Answer 7

Measure of eosinophilic inflammation in airways
Monitors treatment and compliance
Positive test (>40ppb) supports diagnosis of asthma

Question 8

Test of Lung Function

Answer 8

Airway obstruction: FEV1/FVC ration <70%
PEFR monitoring - 20% diurnal variation
Reversible: with bronchodilators - 15%, 200mls improvement in FEV1

Question 9

Management - Long Term

Answer 9

Non-pharmacological: smoking cessation, weight reduction, pollution
Inhaled corticosteroids: eg beclometasone, fluticasone
Inhaled Long Acting Beta2 Agonsist: must be in combination with ICSs - e.g. formoterol, salmeterol
Oral Treatment:oral leukotriene antagonist montelukast, oral theophyllines, in patients with poorly controlled asthma

Question 10

Management - Short Term

Answer 10

SABA - salbulamol, terbutaline as inhaler/nebuliser
Maintenance & Reliever Therapy (MART): LABA formoterol has short onset of action (equivalent of salbutamol).
ICS/LABA combinations - as relievers & preventers
Patients can take additional doses for 2-3 days
Address and treat inflammatory aspect with both

Question 11

2 Different Inhaler Devices

Answer 11

Dry Power Inhalers: activated by inspiration - powdered drug dispersed into particles
Pressurized Metered Dose Inhalers: drug dissolved in a propellant hydroflurocarbons under pressure - valve system releases a metered dose
Consider: side effects, cost, where patients are in treatment

Question 12

Very Specialised treatment

Answer 12

Monoclonal antibodies
Anti-IgE injections (omalizumab)
Anti IL-5 treatment (mepolizumab)

Question 13

Acute Severe Asthma

Answer 13

PEFR: 33-50%, breathless
Respirations > 25 breaths/minute
Pulse > 110 breaths/min
Life threatening: SpO2 < 92%, silent chest, cyanosis, feeble resp effort, hypotension, arrythmia

Question 14

Management of Acute Severe Asthma

Answer 14

Oxygen
Corticosteroids
Nebulised Bronchodilators (salbutamol & ipratropium bromide)
If poor response: IV MgSO4/IV aminophylline
Discharge from Hospital: discharge meds, inhaler technique checked, PEFR > 75% of best, treatment with oral & inhaled steroids + bronchodilators, follow ups scheduled