Asthma

Question 1

Define asthma

Answer 1

A chronic inflammatory condition of the airways that causes recurrent episodes of wheezing, breathlessness, chest tightness and cough, particularly at night and/or early morning.
These symptoms are usually associated with widespread but variable bronchoconstriction and airflow limitation that is at least partly reversible, either spontaneously or with treatment.

Question 2

What 3 factors contribute to airway narrowing?

Answer 2

1. Bronchial muscle contraction, triggered by a variety of stimuli
2. Mucosal swelling/inflammation, caused by mast cell and basophil degranulation resulting in the release of inflammatory mediators 3. Increased mucus production.

Question 3

What are precipitants of asthma?

Answer 3

• Cold air, exercise, emotion, allergens (house dust mite, pollen, fur), infection, smoking and passive smoking, pollution, NSAIDs, β‎-blockers.

Question 4

What are signs of asthma?

Answer 4

Tachypnoea; audible wheeze; hyperinflated chest; hyper-resonant percussion note; ↓air entry; widespread, polyphonic wheeze

Diurnal variation and has triggers
History of atopy

Question 5

What are differentials of asthma?

Answer 5

Pulmonary oedema
COPD
Large airway obstruction
SVC obstruction
Pneumothorax 
Bronchiectasis

Question 6

What investigations in asthma?

Answer 6

Peak flow: diurnal variation
Spirometry: ○ Obstructive (decreased FEV1/FVC ratio <0.7 and raised RV)
>15% improvement (reversibility) when given B2 agonist or steroids

CXR

Lung function tests: if unsure of diagnosis

Question 7

What medications in asthma?

Answer 7

1. SABA as needed

If used >1x daily, or nocturnal Sx:

2. • ICS

3 + LABA

If beneficial but not controlled, increased ICS dose.

If not beneficial, stop LABA and increase ICS.

4. Try leukotriene receptor antagonist or oral theophylline.
5. Other drugs, oral steroids.

Question 8

What investigations in a severe life threatening asthma attack?

Answer 8

Peak flow  
Oxygen saturations 
Sputum culture 
Bloods 
 ABG
CXR

Question 9

What is management of acute asthma attack?

Answer 9

1. Oxygen 40-60% to maintain saturations 40-60%
   
   2. Salbutamol or terbutaline nebulised with oxygen
   3. Ipratropium bromide nebulised
   4. Oral prednisolone or IV hydrocortisone

Try Mg sulphate infusion, or IV aminophylline

Discuss with ICU

Question 10

What are Sx of acute asthma attack

Answer 10

Will depend on severity

Increasing Sx, low PEF, high RR, HR, struggling to complete sentences