ASTHMA

Question 1

Define asthma.

Answer 1

Asthma is a reversible chronic inflammatory disorder of the airways characterised by airflow obstruction and bronchospasm.

Question 2

What symptoms would a person suffering an asthma attack present with? (Name 4)

Answer 2

Dyspnoea
Wheeze
Cough (often at night)
Production of sputum

Question 3

What signs would a patient suffering an asthma attack present with?

Answer 3

Tachypnoea
Audible wheeze
Hyperinflated chest
Hyperresonant percussion
Reduced air entry
Widespread polyphonic wheeze

Question 4

What further signs would a severe asthma attack present with? (Name 3)

Answer 4

Inability to complete sentences
Tachycardia >110 bpm
Respiratory rate >25/min
PEF 33-50% predicted

Question 5

What signs and symptoms would make you worry that this patient was suffering a life threatening attack? (Name 4)

Answer 5

Silent chest
Confusion 
Exhaustion
Cyanosis
Sats of less than 92%
PEF of less than 33%

Question 6

What are the 3 separate physiological factors that contribute to airway narrowing?

Answer 6

Bronchial muscle contraction
Mucosal swelling/inflammation caused by mast cells and basophil degranulation
Increased mucus production

Question 7

What tests are needed to confirm the diagnosis of an asthma attack and to work out the severity, and hence the treatment plan?

Answer 7

Peak Expiratory Flow
Sputum culture
Blood tests - FBC, U&E, CRP, blood cultures
O2 sats
ABG
Chest X-ray (to exclude pneumonia and pneumothorax)

Question 8

Name as many recognised precipitants of asthma attacks as you can. (There are 11 on the answer slide)

Answer 8

Cold air
Exercise
Emotion
House dust mites
Pollen
Fur
Infection
Smoking (including passive smoking)
Pollution
NSAIDs
Beta-blockers

Question 9

What does an ABG of an asthmatic patient suffering an attack usually show? What would make you worried and what would you need to do in this situation?

Answer 9

ABG may show a slightly reduced PaO2 but should also show a reduced PaCO2 due to hyperventilation. If PaCO2 is raised or even within normal range, patient may need transferring to HDU or ITU for ventilation as this signifies respiratory failure.

Question 10

What is the first line of treatment for someone recently diagnosed with asthma?

Answer 10

Short acting beta-2 agonist inhaler - Salbutamol

Question 11

What is the second step in the approach to treatment of asthma?

Answer 11

Short acting bronchodilators (Salbutamol/Ipratropium) plus inhaled steroids
NB do not start long acting beta-2 agonists without inhaled steroids in asthmatics

Question 12

What is the third step in the approach to treatment of asthma, having added inhaled steroids to the short acting bronchodilators?

Answer 12

Add long acting beta-2 agonists. This will usually be in the form of a combination inhaler with the steroid, such as Seretide inhaler.

Question 13

Having added long acting beta-2 agonists to the treatment package for an asthmatic, what else can be done if they are still suffering symptoms? (Step 4 of the approach to treatment of asthma)

Answer 13

Increase dose of inhaled steroid
OR
Consider leukotriene receptor antagonist - Monteleukast

Question 14

If treatment with increased dose of inhaled steroid or treatment with leukotriene receptor antagonist is still not sufficient to control asthma, what is the last step that can be tried in the treatment of asthma?

Answer 14

Oral steroids - 40 mg Prednisolone

Question 15

Why does an immune response lead to reduced sympathetic activity in the bronchi?

Answer 15

IgE has been shown to directly block beta-2 receptors.

Question 16

What is the difference between immune mediated and non-immune mediated asthma?

Answer 16

Immune mediated asthma most frequently involves an allergen triggering the asthma attack through an immune response (involving mostly mast cells and eosinophils) which leads to bronchoconstriction and bronchial inflammation.

Non-immune asthma is a non-allergic asthma attack which doesn’t involve the immune system as a trigger. Stimuli which lead to such an attack include exercise, cold, smoke and hyperventilation. They also cause bronchoconstriction triggering the asthma. Immune mediated bronchial inflammation may follow an non-allergic asthma attack.

Question 17

In the management of an acute asthma attack what are the two keys things to gather from the history?

Answer 17

Best PEF

Any previous admission to ITU

Question 18

What is the differential diagnosis for someone who is having an acute asthma attack?

Answer 18

COPD exacerbation
Pulmonary oedema
Upper respiratory tract infection
PE
Pneumothorax
Anaphylaxis

Question 19

What would make you think that a patient was experiencing a severe asthma attack rather than a mild one?

Answer 19

Unable to complete sentences
RR > 25
HR > 110
PEF 33-50% of best

Question 20

What would make you think that a patient was experiencing a life threatening asthma attack rather than a severe one?

Answer 20

PEF < 33%
Silent chest
Cyanosis
Feeble respiratory effort
Bradycardia
Hypotension
Exhausted/confused/coma
ABG shows normal or high CO2 (>4.6 kPa)

Question 21

Which is the most worrying observation in this 25 year old patient experiencing an asthma attack?

HR 120
BP 110/72
RR 30
O2 sats 88%
pH 7.35
PaO2 5.9 kPa
PaCO2 4.9kPa
Bicarb 24 mmol/L

Answer 21

The PaCO2 should be much lower in someone who is hyperventilating during an asthma attack. The fact that the CO2 is in the normal range despite the resp rate shows that this is a life threatening asthma attach. Treatment with high flow oxygen and IV magnesium sulphate is needed immediately.

Question 22

What are the treatment guidelines for someone experiencing a severe or life threatening asthma attack?

Answer 22

Warn ITU
Salbutamol 5 mg nebulised with oxygen
Hydrocortisone 100 mg IV/Prednisolone 40-50mg PO
Ipratropium 0.5 mg nebulised
Single dose of magnesium sulphate 1.2-2 grams IV

Question 23

Post a severe asthma attack, what criteria must be met before discharge can be considered?

Answer 23

Stable on meds for 24 hours
Good inhaler technique
PEF >75% predicted
Morning PEF must be within 25% of best PEF
Discharge with steroids and bronchodilator therapy

Question 24

How would you treat someone experiencing a non-severe asthma attack?

Answer 24

Salbutamol 5 mg nebulised with O2
Prednisolone 30 mg PO
If PEF <75%, repeat salbutamol
Monitor O2 sats, HR and RR

Question 25

Which of the following would not be suitable for treating someone currently experiencing a severe asthma attack?

High flow oxygen
High-dose nebulised beta-2 agonists
Intravenous magnesium sulphate
Leukotriene receptor antagonists
Steroids

Answer 25

Leukotriene receptor antagonists