Asthma

Question 1

What is asthma?

Answer 1

Paroxysmal, recurrent attacks of cough, wheeze and dyspnea due to reversible airways narrowing with inflammation and hyper-responsiveness

Question 2

Asthma risk factors and triggers?

Answer 2

1. Genetic predisposition
2. Often precipitated by environmental triggers
3. Hormonal factors
4. Gastrointestinal Reflux
5. Stress
6. Drugs: beta-blockers, NSAIDs
7. Occupational Asthma

Question 3

State environmental triggers of asthma?

Answer 3

1. Allergens
   e.g. dust, pets, pollens, occupational
2. Infections
   e.g. viral
3. Environmental pollutants
   e.g. smoke, dust
4. Physical factors
   e.g. cold air, exercise, hyperventilation

Question 4

What is occupational asthma?

Answer 4

it is characteristically associated with symptoms at work with relief on weekends and holidays
- If removed from exposure within the first 6 months of symptoms, there is usually complete recovery

Question 5

Describe the hormonal asthma trigger?

Answer 5

• Some women show premenstrual worsening of asthma, which can occasionally be very severe
• are related to a fall in progesterone and in severe cases may be improved by treatment with high doses of progesterone

Question 6

What is the pathophysiology of asthma?

Answer 6

1. genes predisposing to allergies + lack of early Th1 stimulation = increase Th2 expression
2. Th2 releases IL-4 and IL-3
3. B cells are activated and release IgE antibodies
4. mast cells are activated by the IgE antibodies and allergens
5. mast cells release histamine, leukotrines and cytokines
6. there is a hyperactive response - bronchospasm, edema, airway obstruction
7. there is chronic inflammation and tissue remodeling

Question 7

Roles of Th1 and Th2?

Answer 7

Th1 - protective immunity
Th2 - allergic disease e.g. asthma

Question 8

Factors favoring Th1 phenotype?

Answer 8

1. presence of older sibling
2. early exposure to day care
3. TB, measles, hepatitis A infection
4. rural environment

Question 9

Factors favoring Th2 phenotype?

Answer 9

1. widespread use of antibiotics
2. western lifestyle
3. urban environment
4. diet
5. sensitization to house dust mites and cockroaches

Question 10

Clinical features?

Answer 10

1. Episodic breathlessness
2. cough
3. expiratory wheezing
4. Specific triggers (clinical history!)

Question 11

What 2 clinical tests will show you characteristic features of asthma?

Answer 11

1. peak flow diary
2. spirometry

Question 12

Peak flow diary in asthma?

Answer 12

• normal PEFR is 300-700 litres/min
• shows >20% diurnal variation on > / = 3 days in a week for two weeks

Question 13

Explain the diurnal variation in the peak flow diary?

Answer 13

in the morning our bronchioles are more constricted so that’s when asthma patients usually have their exacerbations

Question 14

Spirometry features in asthma?

Answer 14

decrease in FEV1 > 15% in response to stimulus challenge
e.g exercise, histamine, metacholine
Note: FEV1 improves by ≥ 12% and ≥ 200mls with bronchodilators

Question 15

What is the skin pricktest for asthma?

Answer 15

a medical provider pricks your skin using a needle with a small amount of allergen
- if you are allergic the spot will get red, swollen and itchy

Question 16

How does spirometry work?

Answer 16

a spirometer measures the amount of air you can breathe out in one second and the total volume of air you can exhale in one forced breath
- these measurements will be compared with the expected normal result for someone of your age, height and sex

Question 17

Classification of drugs for asthma?

Answer 17

1. bronchodilators
2. leukotriene antagonists
3. mast cell stabilizers
4. corticosteroids
5. anti Ig-E antibody

Question 18

Bronchodilator classses and drugs?

Answer 18

1. Beta-sympathomimetics
   - salbutamol, terbutaline, bambuterol, salmeterol
2. methyl xanthines
   - theophylline, aminophylline
3. anticholinergics
   - ipatropium bromide, tiotropium bromide

Question 19

Leukotriene antagonist drugs?

Answer 19

1. montelukast
2. zafirlukast

Question 20

Mast cell stabilizer drugs?

Answer 20

1. sodium chromoglycate
2. ketotifen

Question 21

Corticosteroids drugs?

Answer 21

1. systemic
   - hydrocortisone, prednisolone
2. inhalational
   - bevlomethasone, budesonide, fluticasone, flunisolide

Question 22

Anti Ig-E antibody?

Answer 22

omalizumab

Question 23

Features of mild asthma?

Answer 23

1. undistressed
2. RR < 25
3. HR > 110bpm
4. O2 stats > 97%
5. PEFR > 75% predicted

Question 24

Treatment of mild asthma?

Answer 24

1. 5mg salbutamol nebulizer
   OR
2. salbutamol 4-10 puffs pMDI
   - repeat every 20 mins and reassess in 1 hr
   - discharge if stable

Question 25

Features of moderate asthma?

Answer 25

1. distressed but no signs of severe asthma - can complete a sentence 2. PEFR 50-75%

Question 26

Treatment of moderate asthma?

Answer 26

1. salbutamol 4-10 puffs pMDI or spacer - repeat every 20 mins for 1 hr OR 2. 5mg salbutamol nebulizer - repeat after 15-20 mins 3. prednisolone 40mg PO od - observe overnight

Question 27

What do you discharge mild and moderate asthma on?

Answer 27

1. prednisolone 40mg PO od for 5-7 days - prednisolone 1mg/kg (max 50 mg od) 2. salbutamol inhaler 3. beclomethasone inhaler 2 buffs bd 4. see clinic in 4-6 weeks

Question 28

Signs of severe asthma?

Answer 28

1. distressed with signs of severe asthma 2. cannot complete a sentence 3. RR>25 4. HR>110bpm 5. O2<97% 6. PEFR- 33-50%

Question 29

Treatment of severe asthma?

Answer 29

1. 5 mg salbutamol nebulizer - repeat every 20 minutes for i hr and then reassess O2 supplement (aim 93-95%) 2. prednisolone 40mg PO od 3. magnesium sulphate 2g slow IV (over 20 mins) stat (dose 40mg/kg max 2g) 4. +/- aminophylline IV (250 mg slow over 20 mins)

Question 30

Signs of life threatening asthma?

Answer 30

1. exhausted 2. drowsy 3. confused 4. silent chest 5. cyanotic O2 stats <92% 6. PEFR 33%

Question 31

Treatment of life threatening asthma?

Answer 31

1. 5mh salbutamol nebulizer and repeat every 10-20 mins for reassess O2 supplement 2. prednisolone 40mg PO od or IV hydrocortisone 2--mg 6-8 hrly 3. magnesium sulphate 2g slow IV 4. +/- aminophylline IV 5. ICU review for elective intubation and mechanical ventilation

Question 32

Ongoing care for severe and life threatening asthma?

Answer 32

1. regular medical review 2. if no improvement, needs ITU review - consider pneumothorax - chest infection - other respiratory pathology 3. ensure adequate hydration - including IV fluids

Question 33

Treatment of a mild/moderate asthma attack?

Answer 33

1. Carefully teach and monitor correct inhaler technique 2. Salbutamol inhaler 4-10 puffs via a spacer device or salbutamol nebulizer repeated as required initially, then every 8 hours 3. Keep under observation at least 24 hours after the attack

Question 34

Clinical signs of life threatening asthma?

Answer 34

1. Silent chest 2. Central cyanosis 3. Tachypnoea RR > 30 - exhaustion - inability to speak through a sentence 4. Persistent tachycardia > 110 bpm - bradycardia - hypotension - pulsus paradoxus 5. Use of accessory muscles 6. Confusion, agitation, coma 7. Peak flow < 33 % of predicted

Question 35

What to do for life threatening asthma?

Answer 35

immediate hospitilization

Question 36

Severe/life threatening asthma differentials?

Answer 36

1. Acute LVF 2. Pneumothorax 3. PE 4. Upper airways obstruction 5. Massive pleural effusion 6. Severe pneumonia

Question 37

Severe asthma treatment?

Answer 37

1. IV line, rehydrate with 0.9% NS 2. High flow oxygen 5l/min 3. Salbutamol nebuliser solution 5 mg by nebulizer - repeat as required (every 15-30 min), then q 6 hrs or Salbutamol MDI 4 puffs via spacer 4. Hydrocortisone 200mg iv q 8 hours 3-5 days 5. If you use steroids > 10 days, gradually taper the dose for steroids, 10 mg per week initially, and decrease by 5 mg until you stop. 6. Antibiotic: Amoxycillin 500 mg q 8 hours or Doxycycline

Question 38

What to do if there is no improvement in treatment for severe asthma?

Answer 38

1. add Aminophylline 250 mg slow over 10 min 2. If no response: - Aminophylline 250 mg over 12 hours - Magnesium sulphate 1.2-2 g iv over 20 min - Adrenaline 0.5-1.0 ml of 1:1000 slowly nebulised or i.m.

Question 39

Management of acute asthma principles?

Answer 39

1. Exclude other conditions: - stridor and upper airway obstruction (inspiratory difficulty rather than expiratory wheeze of asthma) - heart failure 2. Give antibiotics - only with evidence of precipitating infection

Question 40

What to do before discharge of n acut asthma attack?

Answer 40

Check correct use of Metered Dose Inhaler (MDI) in your patients - use a spacer device, especially during attacks. - Can use plastic bottle (cut hole in bottom of bottle), shake MDI before use, prime bottle with 2 puffs

Question 41

Maintenance and preventive treatment of asthma?

Answer 41

STEP 1: Salbutamol MDI with Spacer STEP 2: if required more than once every day add inhaled steroid (Beclamethasone 2 puffs) BID, increase to 4 puffs as required STEP 3: Refer to specialist if not controlled

Question 42

Describe assessment of symptom control?

Answer 42

in the past 4 weeks has the patient had: 1. daytime symptoms more than twice a week 2. any night waking due to asthma 3. SABA reliever needed more than twice a week 4. any activity limitation due to asthma

Question 43

Classifying level od asthma control?

Answer 43

1. well controlled - none 2. partly controlled - 1-2 symptoms 3. uncontrolled - 3-4 symptoms

Question 44

Stepwise management of asthma?

Answer 44

1. mild intermittent - SABA 2. mild persistent - SABA - ICS low dose 3. moderate persistent - SABA - ICS low dose - LABA 4. severe persistent - SABA - ICS high dose - LABA 5. very severe persistent - SABA - ICS high dose - LABA - OCS