Asthma Flashcards
1
Q
What is the definition of asthma
A
- a combination of cough, wheeze or breathlessness with variable airflow obstruction
2
Q
what type of disease is asthma
A
Heterogenous disease usually characterised by chronic airway inflammation
3
Q
what are the 4 symptoms of asthma
A
- wheeze
- shortness of breath
- chest tightness
- cough
- with evidence of variable airflow limitation - its reversible
4
Q
How many people does asthma affect
A
◦5.4 million people in the UK receive treatment for asthma: 1 in 11 children and 1 in 12 adults
◦Affecting 1 – 18% of the population of different countries
5
Q
what is a phenotype
A
A phenotype is defined as the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.
6
Q
Name the 5 differnet phenotypes of asthma
A
◦Allergic asthma ◦Non-allergic asthma ◦Adult-onset (late-onset) asthma ◦Asthma with persistent airflow limitation ◦Asthma with obesity
7
Q
Describe allergic asthma
A
- asthma due to allergies
- has lots of eosinophils
8
Q
describe non allergic asthma
A
- more neutrophil based
- do not have an allergen that triggers asthma
- not responsive to steroids
9
Q
Describe adult-onset asthma
A
- can be due to occupational asthma - working in a bakery or a factor
10
Q
describe asthma with persistent airflow limitation
A
- due to chronic inflammation that has become irreversible
11
Q
what receptors cause bronchodilation
A
- sympathetic = b2 receptors - these cause bronchodilator and mucocillary clearance
12
Q
what receptors cause bronchoconstriction
A
- Parasympathetic = muscarinic receptors and causes bronchoconstriction
13
Q
What holds the large airways open
A
- Cartilage holds the large airways open
14
Q
How do you work out flow
A
pressure change/resistance
15
Q
what causes an increase in flow
A
- increased pressure change
- or decreased resistance (pouseille’s law: resistance 1/r4)
16
Q
Describe the pathology of asthma
A
Inflammatory process:
- obstruction
- airway hyper-responsiveness
17
Q
Describe what happens in the acute and late phase pathology of asthma
A
Acute phase: Mast cells cause - bronchospasm - oedema - mucous
Late phase
TH2 helper cells cause B cells to be produced and this causes IgE and eosinophil production this leads to:
- constriction
- muco-secretion
18
Q
What are the extrinsic, intrinsic and occupational causes of asthma
A
Extrinsic
- air pollution
- allergen exposure
- maternal smoking
- hygiene hypothesis
- genetics
Intrinsic
- non allergic
- less responsive
- colds/infections
Occupational
- allergens at work
19
Q
how can you diagnose asthma
A
- no single diagnostic test
- clinical assessment supported by objective evidence of variable airflow obstruction or airway inflammation
20
Q
What are the features that make asthma more likely
A
More than one episode of
- wheeze
- breathlessness
- chest tightness
- cough
Variability
- worse at night and in the O-ring (diurnal variability)
- trigged by allergen, exercise, cold air, aspirin or beta blocker
- atomic features
- family history of asthma/atopy
- objectively auscultated wheeze on clinical examination
- low PEFR or FEV
21
Q
why do you produce NO in asthma
A
- due to high eosinophils which help activate NO producing
- eosinophils use inducible nitric oxide synthetase (iNOS) to produce NO
22
Q
What are the differential diagnosis of asthma
A
- COPD
- Obstruction due to a foreign body
- anaphylaxis
- pulmonary oedema
23
Q
What are the differences between Asthma and COPD
A
Asthma
- reversible
- daily FEV1 variation
- can be related to eosinophils and allergies
COPD
- older
- smoking history
- sputum production
- not reversible
24
Q
what is the treatment difference between asthma and COPD
A
Asthma is chronic inflammation so you use a higher dose of steroids whereas COPD you use lower doses of steroids
25
Name the ways in which you can measure asthma
- spirometry
- fraction exhaled nitric oxide (FENO)
- Direct challenge testing (e.g. methacholine)
- peak flow variability
26
What does spirometry measure
- FEV1/FVC
27
what is the diagnostic result of asthma in spirometry
- FEV1/FVC less than 70%
28
How can bronchodilators reversibility prove asthma
- FEV1 is measured pre and post beta agonist (salbutamol) inhalation with a spirometry
- if there is an improvement of 12% or 200ml in FEV1 then it shows that there is asthma
29
How can FENO show asthma
- Breath test - marker of eosinophilic inflammation
- greater than 40ppb
- multiple confounders
- 1 in 5 have a false positive/negative
30
How does a direct challenge testing show asthma
- Drop in FEV1 when exposed to provoking substance such as histamine or methacholine
- concentration required to cause 20% fall in FEV1 (PC20) of 8mg/ml or less
- low false negative rate
- 2/3rds with positive test have asthma
31
describe how peak flow shows asthma
- twice daily readings over 2 weeks - diurnal variation
| - should show 20% variability in PEF
32
What other tests can be helpful for diagnosing asthma
- IgE
- allergy/skin prick testing
- FBC/eosinophil count
33
How do you treat asthma
- avoidance of triggers and allergens
| - medical
34
What lifestyle advice should be given for asthma
* Avoid smoking exposure
* Weight reduction
* Breathing control exercises may help
• Not recommended:
o House dust mite avoidance
o Air ionisers
35
What do specialists nurses do in the management of asthma (MENTION IN THE OSCE THAT SPECIALIST NURSES DEAL WITH ASTHMA)
Asthma nurse review at/shortly after admission improves
- symptom control
- self management
- re-attendance rates
- Review post discharge within 30 days
36
What does a self management plan of asthma include
- how to use treatment
- self monitoring/assessment skills
- action plan with regard to goals
- recognition and management of exacerbations
- allergen/trigger avoidance
37
what is the recovery medication for asthma
- short acting B2 agonists - salbutamol
38
What is the mechanism of action of salbutamol
- relax smooth muscle
| - receive bronchospasm
39
Give examples of short acting B2 agonists
- Salbutamol
| - terbutaline
40
Give examples of long acting B2 agonists
- salmeterol
| - formoterol
41
what are the side effects of B2 agonists
- tremor
- tachycardia
- sweats
- agitation
42
What is the mechanism of action of corticosteroids
- decrease inflammation
43
Name examples of corticosteroids for asthma
- budesonide
- beclometasone
- fluticasone
44
What are the side effects of corticosteroids in the treatment of asthma
- oral candidiasis - IN OSCE MENTION THEY HAVE TO WASH THERE MOUTH AND THE INHALER AFTERWARDS TO PREVENT THIS
- systemic side effects rare with inhaled corticosteroids
45
How to leukotriene antagonists work
- block leukotriene receptors in smooth muscle this reduces bronchoconstriction
46
Name an leukotriene antagonists
- Montelukast
47
What are the side effects of leukotriene antagonists
- nausea
| - headache
48
what line is luekotreine antagonists in the treatment of asthma
2nd line after corticosteroids in NICE guiltiness
| 3rd in BTS guidelines
49
describe how anti IgE is used as a treatment form asthma
- monoclonal antibody to IgE
| - decreases IgE
50
What is an example of anti IgE
- omalizumab - given SC
51
what are the side effects of anti IgE
* itching
* joint pain
* headache
* nausea
* anaphylaxis
52
What do you need to consider when giving IgE
* confirmed allergic IgE-mediated asthma as an add-on to optimised standard therapy
* continuous or frequent treatment with oral corticosteroids (defined as 4 or more courses in the previous year)
53
describe the BTS and NICE guidelines for treatment of asthma
BTS
- low dose ICS
- add inhaled LABA to low dose ICS
- increase ICS to medium dose or add an LTRA
- refer patient to specialist care
NICE
- low dose ICS
- offer LTRA
- Add LABA
- MART then increase ICS in MART or fixed dose ICS/LABA and SABA then LAMA or theophylline
54
describe what should happen with the dosage of corticosteroids
- patients should be maintained at the lowest possible dose of inhaled corticosteroids
- reduction of about 25-50% each time should be considered every 3 months
55
What is the definition of uncontrolled asthma
• 3 or more days a week with symptoms or
• 3 or more days a week with required use of a SABA for symptomatic
relief or
• 1 or more nights a week with awakening due to asthma.
56
How should you assess the risk of future attacks
Ask about history of previous attacks, objectively assessing current asthma control, and reviewing reliever use
* In children, regard comorbid atopic conditions, younger age, obesity, and exposure to environmental tobacco smoke as markers of increased risk of future asthma attacks
* In adults, regard older age, female gender, reduced lung function, obesity, smoking, and depression as markers of a slightly increased risk of future asthma attacks
57
how does the asthma control test work
* The scores range from 5 (poor control) to 25 (complete control)
* An ACT score >19 indicates well-controlled asthma.
58
what are the severity levels of asthma
* Near-fatal
* Life-threatening
* Acute severe
* Moderate
* Brittle
59
what is the difference between type 1 and type 2 brittle asthma
* Type 1: wide PEF variability (>40% diurnal variation for >50% of the time over a period >150 days) despite intense therapy
* Type 2: sudden severe attacks on a background of apparently well-controlled asthma
60
Describe what moderate asthma looks like
- respiration rate less than 25/min
- pulse less than 110 bpm
- PEF greater than 50-75% best or predicted
- speech normal
- no features of acute severe asthma
61
Describe what acute severe asthma looks like
Any one of:
- PEF 33-50% best or predicted
- respiratory rate is greater than 25/min
- heart rate is 119 bpm or greater than 110 bpm
- inability to complete sentences in one breath
Admit if persisting symptoms
62
What does life threatening asthma look like
Any one of the following in a patient with severe asthma:
- PEF less than 33% best or predicted
- SpO2 less than 92%
- PaO2 less than 8kPa
- normal PaCO2 (4.6-6kPa)
- silent chest
- cyanosis
- feeble respiratory effort
- bradycardia
- dysrhythmia
- hypotension
- exhaustion
- confusion
- coma
- call an anaesthetist
- 33-92 chest (PEF <33%, sats <92%, cyanosis, hypotension, exhaustion, silent chest, tachy or bradycardia)
63
What does near fatal asthma look like
Raised PaCO2 and/or requiring mechanical ventilation with raised inflation pressures
64
who do you admit in an asthma attack
- life threatening attack
- severe attack that does not response to initial treatment
Other admission criteria include
- previous near fatal asthma attack, pregnancy, an attack occurring despite already using oral corticosteroid and presentation at night
65
Who do you discharge after an asthma attack
PEF greater than 75% after 1 hour unless
- significant symptoms
- compliance concerns
- lives along
- psychological/physical/learning problems
- previous near fatal or brittle asthma
- pre-existing steroids
- night time
- pregnant
66
How do you treat acute asthma
ABC
Oxygen
- aim stats of greater than 92%
- Oxygen driven nebuliser
- if acutely unwell = 15L supplemental via a non rebreathe mask
Bronchodilation with short acting beta 2 agonists (SABA)
- High dose inhaled SABA
- in patients without life threatening or near fatal asthma this can be given by a standard inhaler or nebuliser
- if patient has life threatening asthma then nebulised SABA
Corticosteroids
- 40-50mg of prednisolone orally daily which should be continued for at least 5 days or until the patient recovers from the attack
IV fluids
- rehydration
- correct electrolyte imabalance
reassess
- every 15 minutes with PEFR
67
What drugs do you give in actue asthma
OSHITP
- Oxygen
- Salbutamol
- Hydrocortisone/Prednisolone
- Ipratropium bromide
- Theophylline
- ! Magnesium sulphate
68
How do you give salbutamol in acute asthma
Nebulised with oxygen
| 2.5-5mg every 10 minutes
69
What are the side effects of using salbutamol in an acute asthma attack
- Tremor
- Arrhythmias
- Hypokalaemia (monitor ECG)
70
How do you give hydrocortisone in acute asthma
IV 100-200mg QDS
| Or prednisolone PO 40mg OD
71
How do you give ipratropium bromide
Nebulised with oxygen
500 micrograms every 4-6 hours
- given in patients who do not respond to SABA or corticosteroid
72
What are the side effects of nebulised ipratropium bromide
- Arrhythmias
- cough
- dizziness
- dry mouth
- headache
- nausea
73
Who and how do you give magnesium sulphate to in an acute asthma
- 1.2 – 2 grams over 20 minutes IV
| - Acute severe asthma/ life threatening asthma
74
Who do you give theophylline to and what does it do
- Inhibit phosphodiesterase and increase cAMP – smooth muscle
- Life-threatening asthma
- senior guidance
75
What are the side effects of theophylline
* Palpitations (chronotropic effect)
* Arrhythmias (chronotropic effect)
* Nausea
* Seizures (stimulates CNS)
* Alkali burns if extravasation occurs
* Drug interactions
76
When do you involve ITU
- All patients requiring ventilatory support
- Near fatal asthma
Life threatening / acute severe not improving
• Worsening peak flow
• Persistent/worsening hypoxia • High PaCO2
• Low pH
• Exhaustion
• Drowsiness
• Respiratory arrest
77
How do you monitor acute asthma
- regular peak flow
- oxygen saturations and chest auscultation
```
ABG
Repeat at 1 hour if:
- hypoxic
- normo-hypercapnoeic
- patient deteriorates
```
Bloods
- potassium
- glucose
ECG
- potassium
- magnesium
- B2
78
what is the discharge planning after an acute asthma attack
Improved symptoms
◦ clinical signs compatible with home management
◦ β2-agonist requirements
◦ therapy can be continued at home
Improved peak flow
◦ >75% best/predicted
◦ <25% diurnal variation
Follow up
o within 48 hrs
o <30 days post discharge by GP/nurse specialist
o under specialist supervision indefinitely for near-fatal asthma and
at least 1 yeat for severe asthma attack
79
Do these OSCE examples
- Explain to a patient the difference between a reliever and preventer inhaler
- Demonstrate the use of metered dose inhaler with and without a spacer to a patient
Do it
80
What is the differential diagnosis for wheeze
- asthma
- allergies
- GORD
- infection
- obstructive sleep apnoea
81
How do you diagnose occupational asthma
- PEF taken at home and at work and compared
82
What measures can be taken to prevent and treat occupational lung disease
- avoid the inhaled substances that cause the lung disease
| - PPE
