Asthma

Question 1

asthma

Answer 1

chronic inflammation condition of the airways.
causes episodic exacerbation of bronchoconstriction.

bronchoconstriction- obstruction. reversible airway obstruction that responds to bronchodilators and salbutamol. causes hypersensitivty

triggers:
Infection
Night time or early morning
Exercise
Animals
Cold/damp
Dust
Strong emotions

Question 2

symptoms of asthma

Answer 2

Episodic symptoms
Diurnal variability. Typically worse at night.
Dry cough with wheeze and shortness of breath
A history of other atopic conditions such as eczema, hayfever and food allergies
Family history
Bilateral widespread “polyphonic” wheeze heard by a healthcare professional

Progressively worsening shortness of breath
Use of accessory muscles
Fast respiratory rate (tachypnoea)
Symmetrical expiratory wheeze on auscultation
The chest can sound “tight” on auscultation with reduced air entry

Question 3

investigations of asthma and diagnosis

Answer 3

High probability of asthma clinically: Try treatment
Intermediate probability of asthma: Perform spirometry with reversibility testing
Low probability of asthma: Consider referral and investigating for other causes

1st line line:

• fractional exhaled nitric oxide
• spirometry with bronchodilator reversibility

diagnostic uncertainty:
Peak flow variability measured by keeping a diary of peak flow measurements several times per day for 2 to 4 weeks
Direct bronchial challenge test with histamine or methacholine

Question 4

long-term mx for asthma

Answer 4

1. SABA.
   adrenalin works on smooth muscles of airway and causes relaxation. dilation of the bronchioles to improve bronchoconstriction.
2. ICS beclometasone. reduce inflammation and reactivity of the airways. maintenance or preventer meds
3. LABA- salmeterol
4. LAMA- tiotropium. block acetylcholine receptors
5. Leukotriene receptor antagonist- montelukast. cause inflammation, bronchoconstriction and mucus secretion in the airways.
6. Theophylline- relax bronchial smooth muscle and reduce inflammation. narrow therapeutic window. can be toxic. check levels in blood 5 days after starting treatment and 3 days if dose changed
7. MART- maintenance and reliever therapy. low dose inhaled corticosteroid and fast acting LABA. replaced all inhalers

Question 5

BTS ladder asthma

Answer 5

Add short-acting beta 2 agonist inhaler (e.g. salbutamol) as required for infrequent wheezy episodes.
Add a regular low dose inhaled corticosteroid.
Add an oral leukotriene receptor antagonist (i.e. montelukast).
Add LABA inhaler (e.g. salmeterol). Continue the LABA only if the patient has a good response.
Consider changing to a maintenance and reliever therapy (MART) regime.
Increase the inhaled corticosteroid to a “moderate dose”.
Consider increasing the inhaled corticosteroid dose to “high dose” or oral theophylline or an inhaled LAMA (e.g. tiotropium).
Refer to a specialist.

Each patient should have an individual asthma self-management programme
Yearly flu jab
Yearly asthma review
Advise exercise and avoid smoking

Question 6

acute exacerbation of asthma

Answer 6

rapid deterioration in symptoms. triggered by any typical asthma (infection, exercise, cold weather)

Question 7

grading of asthma (acute)

Answer 7

moderate:
PEFR 50-75%

severe: 
PEFR 33-50% predicted
Resp rate >25
Heart rate >110
Unable to complete sentences

life threatening:
PEFR <33%
Sats <92%
Becoming tired
No wheeze. This occurs when the airways are so tight that there is no air entry at all. This is ominously described as a “silent chest”.
Haemodynamic instability (i.e. shock)

Question 8

acute asthma tx

Answer 8

Moderate:

Nebulised beta-2 agonists (i.e. salbutamol 5mg repeated as often as required)
Nebulised ipratropium bromide
Steroids. Oral prednisolone or IV hydrocortisone. These are continued for 5 days
Antibiotics if there is convincing evidence of bacterial infection
Severe:

Oxygen if required to maintain sats 94-98%
Aminophylline infusion
Consider IV salbutamol
Life threatening:

IV magnesium sulphate infusion
Admission to HDU / ICU
Intubation in worst cases – however this decision should be made early because it is very difficult to intubate with severe bronchoconstriction

serum potassium when on salbutamol*

Question 9

ABG in acute asthma attack

Answer 9

respiratory alkalosis
tachypnoea
drop in Co2

normal co2 or hypoxia is concerning indicates life-threatening asthma.

respiratory acidosis- high co2 is a bad sign of asthm

Question 10

monitoring asthma

Answer 10

Respiratory rate
Respiratory effort
Peak flow
Oxygen saturation
Chest auscultation

Question 11

OSHIT asthma attack

Answer 11

high flow O2
salbutamol (beta agonist)
hydrocortisone (steroid)
ipotrium bromide
thiophylline (specialist)

O SHIT
Oxygen 15L
Salbutamol
Hydrocortisone
Ipratropium- muscarinic antagonist
Theophylline- only by specialist anaesthetist

*mangesium sulphate IV infection (if pt does not respond to initial steroid and bronchodilator therapy)

Question 12

severe vs life threatening asthma

Answer 12

peak flow 33-50% of predicted/best
resp >25/min
HR >110
can’t complete sentences

life threatening
peak flow <33% predicted
silent chest
cyanosis
ABG showing high/normal PaCO2 (reduced respiratory effort)
ABG showing hypoxia or acidosis

Question 13

acute exacerbation of asthma due to URTI

Answer 13

‘acute severe asthma ‘ if peak flow <50% of usual value

salbutamol nebuliser and oral steroids (prednisone 40mg) PO daily for five days.

if no response / worsens then urgent transfer to hosptial

Question 14

suggestive asthma

Answer 14

stepwise approach
(e.g. child who has coughs / wheeze)

if 5-12 y/o trial salbutamol PRN and if being used >x3 per week then add a very low dose inhaled corticosteroid inhaler

Question 15

what is the stepwise management for asthma?

Answer 15

1. inhaled SABA
2. • inhaled ICS
3. • inhaled leukotreine receptor antagonist (LTRA)
4. • LABA and review LTRA
5. maintenance and reliever MART (ICS and LABA in single inhaler)

reivew and monitor