asthma

Question 1

what is the Britsh thoracic society’s definition of asthma

Answer 1

Clinical diagnosis
No consistent gold standard diagnostic criteria
Central to diagnosis is presence of symptoms (more than one of wheeze, breathlessness, chest tightness, cough and variable airflow obstruction)
Heterogenous disease characterised by chronic airways inflammation

Question 2

how does WHO define asthma

Answer 2

Is a disease characterised by recurrent attacks of breathlessness, wheezing which vary in sev and freq from person to person. May occur hour to hour or day to day.

Question 3

how is asthma diagnosed

Answer 3

Combo of clinical assessment, objective tests but symptoms can change

Question 4

why is asthma important

Answer 4

315 million adults worldwide

340,000 deaths a year

Question 5

what is the impact of asthma

Answer 5

5.4 million people are currently being treated for the condition in the UK
On avg 3 people die a day from an asthma attack in UK (185 admissions a day)
NHS spends about a billion on treatment and care
In 2017 1484 died in UK, 50% increase compared to EU

Question 6

what is the natural history of asthma

Answer 6

Most commonly presents in childhood or middle age
50% of kids with mild asthma may grow out of it by 21 (minority returns years later)
70% of kids with persistent asthma with have symptoms in adult life
Adult onset more likely to persist

Question 7

what are causes of airflow obstruction

Answer 7

Bronchoconstriction – contraction of the smooth muscle in the bronchial wall
Bronchial secretions and plugs of mucus – due to inflammation of the bronchial wall
Oedema of the bronchial wall due to inflammation in the lining mucosa of bronchial wall

Question 8

how do normal airways compare to asthmatic airways

Answer 8

narrower due to widened epithelium and smooth muscle (constriction)
mucous plug
enlarged mucous glands

Question 9

what is atopy

Answer 9

Asthma in young people usually inked to atopy
Tendency to form IgE antibodies to allergens
Often associated hay fever or eczema in personal or family history

Question 10

what is the pathophysiology of asthma

Answer 10

antigens activate immune system, causing an inflammatory cascade, bronchoconstriction and inflammation (chemokine recruiting mast cells and eosinophils)

Question 11

what are the symptoms of asthma

Answer 11

Cough
Wheeze
Breathlessness
Chest tightness
Occurs in episodes with periods of no (or minimal symptoms)
Diurnal variability so worse at night or early morning

Question 12

what medications can trigger asthma

Answer 12

aspirin
ibuprofen
beta blockers

Question 13

what are triggering factors of asthma

Answer 13

inflammation - resp infections, allergens, work place
constriction - change in temp, exercise, cold air, emotion and stress, strong odours
others- medications, tobacco, reflux, air pollution, food additives

Question 14

how can asthma be diagnosed

Answer 14

History is crucial – mor than one symptom
Symptom free periods
Past medical history
Family history
Social history
Alternative diagnosis – unlikely but what else could present similarly
Physical exam (except during an attack)

Question 15

what asthma investigations are done by a gp

Answer 15

Peak flow monitoring twice a day for two weeks

Spirometry may show airflow obstruction – could be normal between attacks

Question 16

what asthma investigations are done by a gp/hospital

Answer 16

Chest Xray often normal but may = hyperinflation
Inc eosinophil count in blood
Fraction exhaled nitric oxide (FeNO)
Tests done by hospital
Skin prick or blood tests may confirm allergies

Question 17

what are tests of lung function

Answer 17

Is there airflow obstruction (FEV1/FVC ration <70)
Vary over time
PEFR monitoring – 20% diurnal variation
Reversible
With bronchodilators (salbutalmol, 15% and 200 mls improvement in FEV1 from baseline)

Question 18

how is PEFR monitoring done

Answer 18

best of 3

Question 19

what is FeNO

Answer 19

fraction of exhaled nitric oxide
Measure of airways eosinophilic inflammation
Performed on patients not on any treatment, a positive test (>40ppb) supports diagnosis
Can be done in GP or hospital clinics
Can be used to monitor treatment/look at compliance

Question 20

How can asthma be managed long term, non pharmacologically

Answer 20

Smoking cessation
Weight reduction
Pollution (provoke or exacerbate but effects of allergens, smoking and infection more sig)

Question 21

How can asthma be managed long term, pharmacologically

Answer 21

Control of disease (preventers)
Inhaled corticosteroids (ICS)
Key part of first line treatment (eg beclometasone, fluticasone, budesonide, ciclesonide)

Question 22

what are Inhaled long acting beta 2 agonists (LABA)

Answer 22

Formoterol, salmeterol
In combo with ICS as add on if still symptomatic
Never a single agent treatment alone, ass with inc deaths

Question 23

how can asthma be treated orally (long term)

Answer 23

Oral leukotriene antagonist montelukast
Oral theophyllines
In patients with chronically poorly controlled asthma, low dose long term oral steroids by hospital direction

Question 24

what are Short acting beta agonists (SABA)

Answer 24

Short/immediate relief of symptoms (relievers)

Salbutamol, terbutaline as inhaler (Sal 100mcg) or nebuliser (high dose salbutamol 2.5mg driven by oxygen)

Question 25

what is maintenance and reliever therapy (MART)

Answer 25

LABA formoterol short onset of action, equiv to salbutamol So certain ICS/LABA combos can be relievers too Pts take additional doses ( 4 a day) for short periods (2-3 days) to rapidly treat any worsening asthma symptoms Aiming to address inflammatory aspect by having both ICS and LABA

Question 26

What are the BTS guidelines for asthma

Answer 26

reg preventer - low dose ICS initial add-on therapy - add inhaled LABA to ICS (fixed dose or MART) Additional controller therapies inc ICS to med dose or adding LTRA (+ if no response to LABA then stop it) Specialist therapies

Question 27

what are the two different inhaler devices

Answer 27

DPIs and pMDIs

Question 28

what are DPIs

Answer 28

dry powder inhalers activated by inspiration by patient powdered drug dispersed into particles by inspiration 53-59% effective when used correctly

Question 29

what are pMDIs

Answer 29

pressurised metered dose inhalers drug dissolved into propellant HFCs under pressure, valve system releases metered dose 23-43% effective without spacer, with 55-57%

Question 30

how is inhaler to use decided

Answer 30

Where they are in treatment eg stepping up from ICS to ICS/LABA What device they can use eg dexterity and inspiratory flow Side effects eg oral candidas/thrush (ICS), tremor and tachycardia (SABA/LABA) What device they want to use eg carbon footprint Counter so they know how many doses left Cost

Question 31

what are specialist treatment

Answer 31

for a small number of patients with difficult asthma Monoclonal antibodies (anti IgE injections omalizumab or anti IL5 treatment mepolizumab)

Question 32

what are unintentional barriers to treatment adherence

Answer 32

``` Misunderstanding Poor inhaler technique Language Forgetfulness Stress ```

Question 33

what are intentional barriers to treatment adherence

Answer 33

Concern about side effects Denial Cost

Question 34

how can asthma basely managed

Answer 34

List daily medications and explain List triggers to avoid, importance of smoke free environment Look for deterioration signs, PEFR Names and doses to treat worsening asthma Indicators of how and when to seek medical attention Easy to understand, 2-3 action points, traffic light colour coded

Question 35

what does a PAAP do (personal asthma action plan)

Answer 35

Improves asthma control Reduces emergency contacts with GP Reduces hospital admissions All should see an asthma nurse regularly – window to see asthma control

Question 36

what is acute severe asthma

Answer 36

``` Medical emergency Features PEFR 33-50% Cant complete sentences in one breath Respirations >25 breaths per min Pulse >100 beats per min ```

Question 37

what are life threatening features of asthma

Answer 37

``` PEFR <33% SpO2 <92% (regardless of air or oxygen) Silent chest, cyanosis or feeble resp effort Arrythmia or hypotension Exhaustion, altered consciousness ```

Question 38

how can acute severe asthma be managed

Answer 38

Oxygen Corticosteroids (prednisolone 40-60mgs orally) Nebulised bronchodilators (sal + ipratropium bromide) Poor response = MgSO4 or intravenous aminophylline Exceptionally intubation and ventilation

Question 39

how can someone with acute severe asthma be discharged

Answer 39

Discharge medication for 24 hours Inhaler technique checked and recorded PEFR >75% and PEFR diurnal variability <25% Treatment with oral and inhaled steroids in addition to bronchodilators Own PEFR and written PAAP Follow up GP in a few days and resp centre after a 4 weeks

Question 40

how can peak flow variability vary

Answer 40

over 20% across a day for adults and children if asthmatic

Question 41

what would be an asthmatic results to a direct bronchial challenge test with histamine or methacholine

Answer 41

PC20 of 8mg/ml or less

Question 42

Salbutamol is an adrenoreceptor agonist, which receptor does it activate?

Answer 42

B2 receptor

Question 43

Following salbutamol activation, which cellular second messenger systems are activated and how do they produce the brochorelaxant effect?

Answer 43

``` G protein More ATP to cAMP via adenylate cyclase To protein kinase A IP3 receptor (dec Ca2+ release ER) and MLCK (decreased association with Ca2+ calmouldin complex) inhibit smooth muscle contraction ```

Question 44

Common side effects of salbutamol include?

Answer 44

Increase heart rate (B1 and B2 agonist) Tremor (B2 receptors) Not used in diabetics as can affect beta cell

Question 45

what other conditions can salbutamol be used to treat

Answer 45

COPD

Question 46

how do smooth muscles constrict

Answer 46

``` methacholine>Muscarinic M3 receptor or histamine>Histamine H1 receptor activate G protein Activate PLC (PIP2>IP3) + DAG IP3R>Ca2+ released ER>MLCK Myosin<>P-Myosin MCLP (dec, by PKC, facilitated by DAG) ```