Asthma

Question 1

Define asthma.

Answer 1

A disease characterised by recurrent attacks of breathlessness and wheezing, which vary in severity and frequency from person to person.

Question 2

What is the pathogenesis of asthma? (3)

Answer 2

Airflow limitation/obstruction

Airway hyperresponsiveness

Inflammation of the bronchi

Question 3

What causes airway obstruction in acute asthma? (4)

Answer 3

• Bronchoconstriction
• Airway edema
• Mucous plugs (take weeks to resolve)
• Hyperinflation

Question 4

Define exogenous and endogenous stimuli.

Answer 4

Exogenous are direct stimulation (allergens etc)

Endogenous include activator substances secreted from mast cells and sensory neurons

Question 5

Give 8 triggers for asthma.

Answer 5

• Pets
• Stress
• Cold air
• Pollen
• Exercise
• Anger
• Pollution
• Smoke
• Chemical fumes
• Bugs in the home
• Strong odors
• Dust
• Medication (NSAID, Beta blockers)
• Viral infections (sinusitis)
• GERD

Question 6

Define hygiene theory.

Answer 6

Exposure to bacteria/viruses/fungi in childhood directs the immune and inflammatory response away from the allergic pathways (uncertain)

Question 7

Give 8 symptoms of asthma.

Answer 7

• Cough
• Wheezing
• Shortness of breath
• Common cold
• Chest pain
• Night cough
• Difficulty breathing
• Tachycardia
• Dyspnea

Question 8

Mention 5 important history questions.

Answer 8

Symptoms & Severity

Previous hospitalizations (frequency, last)

Medication history
- What do they take? How is adherence?

Exposures  allergens (“triggers”), smoking, method of cooking

Clues to other possible etiologies
- Infectious symptoms, TB contacts, weight loss, etc.

Question 9

Give 3 important signs on physical examination.

Answer 9

-Vital signs (count the RR)
-Wheezing
-Differential diagnosis,
target your physical
exam to exclude other
pathologies
-Inspiratory or
expiratory?
Signs of atopy

Approach depends on the severity (ABCD in severe exacerbation)

Question 10

How do you diagnose asthma?

Answer 10

Clinical diagnosis: history taking, physical examination and trial of bronchodilators

Peakflow meter:
Measure FEV1 (forced expiratory volume in the first second)
FEV1 reduces in case of obstructed airway, but in case of Asthma is mostly reversible after bronchodilators

(Spirometry; FEV1/FVC before and after bronchodilators)

X-ray (differential)

Question 11

Give 4 differentials for asthma.

Answer 11

• Acute heart failure
• Pneumothorax
• Pulmonary
• Upper airway obstruction
• Massive pleural effusion
• Severe pneumonia

Question 12

Which signs and symptoms point towards life-threatening asthma? (5)

Answer 12

Silent chest

Central cyanosis

Tachypnea (>30 RR), exhaustion, inability to complete sentences

Persistent tachycardia (110 bpm), bradycardia, hypotension, pulsus paradoxes

Use of accessory breathing muscles

Confusion, agitation, coma

Peak flow < 33%

Question 13

How do you manage severe asthma?

Answer 13

O2 (until sat > 95%)

Salbutamol 5mg (<4 yrs 2,5mg) + Ipratropium 0,5mg via nebulizer (if not available via spacer)
Start with 3 back- to-back.
Repeat every 20 min (1st hour)
Observer 24h after symptoms have relieved
Discharge on 2-4 puff every 3-4 h with tapering schedule

Prednisolone 40 mg p.o. OD for 3 days (paeds 1-2mg/kg) OR Hydrocortisone 100mg i.v. OD (<5 yrs 50mg) OR dexamethasone 0,6 mg/kg OD (max 10mg).

No improvement: magnesium sulphate 40 mg/kg i.v. (diluted to at least 10%) over 20 min

OR Aminophylline 5mg/kg i.v. (diluted, max 25 mg/ml) (max 300mg) over 20 min