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Flashcards in Asthma Deck (16)
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1

What is asthma?

Chronic inflammatory disease of the airways

2

What can trigger asthma?

Infection
Allergens
Irritants
Drugs
Temperature
Exercise

3

What is the pathophysiology of asthma?

Hypersensitivity inflammatory reaction

Charactersied by the T-helper 2 response, eosinophils, and mast cells

Cells release histamine, prostaglandins and leukotrienes

Increased number of goblet cells
Smooth muscle hyperplasia
Hypertrophy

4

What is involved the T-helper 2 response?

IL 4 - promotes differentiation of T cells

IL 5 - promotes production of B cells

IL13 - promotes goblet cells, hyperplasia, hypertrophy and mucus secretion

TNF-a - acute phase protein

Leukotriene LTB4 - triggers contraction in airways

Mast cell tryptase - found in allergic response

5

What occurs in baseline asthma?

Chronic inflammation
Thickening of basement membrane
Hypertrophy of airway muscle

6

What happens in acute asthma?

Bronchospasm
Excessive mucus production

7

What are the symptoms of asthma?

Intermittent
- dyspnoea
- wheeze
- cough

8

What are signs of asthma?

Tachypnoea
Audible wheeze
Hyperinflated chest
Hyperresonant percussion

9

What investigations should be done for acute asthma?

Peak flow
Bloods
CXR
Spirometry

10

What is the spirometry pattern in asthma?

Obstructive

Reduced FEV1
Reduced FVC

Can be reversed with bronchodilators

11

How is baseline asthma classified?

Mild intermittent
- symptoms <2 week
- brief attacks
- FEV1 > 80 predicted

Mild persistent
- symptoms >2 week, <1 day
- attacks effect activity
- FEV1 >80

Moderate persistent
- daily symptoms
- affect activity
- FEV1 60-80

Severe persistent
- continuous symptoms
- limited physical activity
- FEV1 <60

12

How is acute asthma classifed?

Moderate
- PEFR 50-75%

Acute severe
- PEFR 33-50%
- RR >25
- HR >110
- inability to complete sentences in one breath

Life threatening
- PEFR <33%
- SpO2 <92%
- PaO2 <8
- cyanosis
- poor respiratory effort
- normal PaCO2

Near fatal
- Raised PaCO2

13

How is baseline asthma managed?

Step 1 = SABA

Step 2 = SABA + low dose inhaled corticosteroid

Step 3 = LABA + ICS

Step 4 = increase ICS dose OR add LTRA

Step 5 = add oral prednisolone

14

How is acute asthma managed?

OH SHIT MAN

Oxygen titrated to 94-98%
Salbutamol nebs
Hydrocortisone IV
Ipratropium bromide nebs
Theophylline/Aminophylline
Magnesium sulphate IV
Anaesthetist intervention
NIV/intubation

15

What are the criteria for safe discharge?

PEFR >75%
5 days abnormal prednisolone
Asthma nurse to assess inhaler technique
GP follow up within 2 days
Respiratory clinic follow up within 4 weeks

16

What are features of poorly controlled asthma?

Difficulty sleeping due to symptoms

Frequent asthma symptoms during the day

Asthma interfering with normal activities

Use salbutamol >1 per week

Decreasing PEFR