210 - Asthma Flashcards

1
Q

With regards to epidemiology what is the prevalence of asthma in the adult welsh population?

A

1:12 welsh adults

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2
Q

According to epidemiological studies list 2 environmental factors that may increase you risk of developing asthma

A
Increased risk
• Caesarian delivery?
• Childhood antibiotic use
• Childhood use of paracetamol?
• Exposure allergen
• Sedentary life style
• Obesity
• Maternal smoking
• Pollution
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3
Q

According to epidemiological studies list 2 environmental factors that may decrease you risk of developing asthma

A
Reduced Risk
• Vaginal delivery
• Breast feeding
• Infection: “The Hygiene Hypothesis”
• Exposure to rural environment
• Increase antioxidants
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4
Q

List 3 pathological features of asthma that may be found at post mortem?

A

Inflammation: eosinophilic
• Mucus plugging
• Airway remodelling:– Airway wall thickening: 50-300% (Bronchial smooth muscle hypertrophy+ airway oedema)– Mucus gland hyperplasia– Loss of surface epithelium– Sub-epithelial fibrosis

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5
Q

List 2 mediators release by mast cells which cause bronchoconstriction clinically

A

Histamine, Prostaglandin D2, Leukotrienes (D4, E4)

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6
Q

T-helper 2 lymphocytes release the cytokine IL-5 which promotes the differentiation of which inflammatory cell type?

A

Eosinophils

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7
Q

In some individuals Non Steroidal Anti-inflammatory Drugs (NSAIDS) may worsen asthma. Which enzyme does this class of medication inhibit?

A

Cycloxygenase (II)

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8
Q

Mr X is an 34 year old asthmatic on inhaled budesonide (200mcg bd) and PRN salbutamol. He attends your surgery as he is not sleeping at night due to cough. What step of the asthma ladder is he currently on? (1 mark)

A

Step 2: low dose inhaled steroid + PRN B2 agonist

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9
Q

Mr X is an 34 year old asthmatic on inhaled budesonide (200mcg bd) and PRN salbutamol. He attends your surgery as he is not sleeping at night due to cough. If you were to increase his treatment name a class of drugs that you would add to his therapy?

A

Try LABA first and if ineffective consider increasing ICS then theophylline or leukotriene receptor antagonist

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10
Q

You are the A&E SHO on call. Miss B is a known asthmatic who presents with cough and SOB. On arrival the paramedics show you her ambulance card. Observations are as follows. Pulse 120, RR26, Sats 94% on air. When you review her she has marked expiratory wheeze and is not able to talk full sentences.Grade her asthma severity

A
Severe 
Severe Asthma PEFR 33-55%
Unable to talk full sentences
Pulse >110
RR>25
Sats
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11
Q

You are the A&E SHO on call. Miss B is a known asthmatic who presents with cough and SOB. On arrival the paramedics show you her ambulance card. Observations are as follows. Pulse 120, RR26, Sats 94% on air. When you review her she has marked expiratory wheeze and is not able to talk full sentences.Name 3 medications that you would consider starting her on.

A

Salbutamol 5mg nebulised,Ipratropium bromide 500mcg nebulised, Prednisolone 40mg od po

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12
Q

Miss B (Severe asthma attack, SOB, reducing sats) continues to deteriorate and the A&E sister is concerned. You do a blood gas:What concerns you about this blood gas?Value (Normal range)pH 7.35 (7.35-7.45)pCO2 6.0 (4.5-6kPA)pO2 10 (11.5.- 13)BE 1 (-1 /+1)Bicarb 25 (24/27)

A

Normal pCO2 ,worsening hypoxia.

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13
Q

Mrs A is a 44 year old atopic asthmatic. She is currently taking symbicort 400/12 turbohaler 2 bd (eformoterol + budesonide). She is also taking uniphyllin (theophylline).What step of the asthma ladder is this patient currently on?

A

Step 4: on high dose inhaled steroids, LABA and theophylline

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14
Q

What enzyme do theophylline tablets inhibit?

A

Phosphodiesterase: inhibiting the breakdown of cAMP

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15
Q

State the side effects you are most likely to see in a patient taking a beclometasone inhaler?

A

Sore throat
Candidiasis
Hoarse voice
In patients taking 1mg/day beclometasone (or equivalent) we should also monitor carefully for systemic side effects

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16
Q

For approximately how long would you expect to see the bronchodilatation effects of salmeterol?

A

12 Hours

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17
Q

Which of the inflammatory mediators does montelukast block from reaching its receptor?

A

Leukotriene

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18
Q

Name a drug or condition which can increase the half life of theophylline? And what symptoms could this cause?

A
Hepatic cirrhosis
CHF
Acute pulmonary oedema
Erythromycin
Fluconazole
Other drugs also inhibit metabolism of theophylline – Symptoms of toxicity include N&V, arrhythmias, restlessness, convulsions, coma
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19
Q

Mary has come to her GP and described worsening asthma symptoms, what would you discuss before making changes to her drug treatment?

A

Possible triggers for worsening symptoms

Inhaler technique and compliance

20
Q

Jack, aged 31years is using a Seretide 125 evohaler (fluticasone and salmeterol) inhaler and a salbutamol inhaler when required. His asthma has been well controlled for many years, with him rarely using his salbutamol inhaler and he has come for a review of his treatment.You decide that stepping down his treatment would be appropriate. Which of his drugs should be discontinued?

A

Salmeterol

But patient should remain on fluticasone and when required salbutamol so no reduction in dose count

21
Q

What is Asthma?

A

A chronic inflammatory disorder of the airways- Airway hyper-responsiveness with airflow obstruction- reversible spontaneously or with treatment

22
Q

How common is Asthma in wales?

A

1 in 10 children

1 in 12 adults

23
Q

Globally, where is asthma more common?

A

In developed countries

24
Q

What are the key symptoms of asthma?

A

Recurrent wheeze
Breathlessness
Cough
Chest tightness

25
Q

What signs are seen in Asthma?

A

Diurnal variation - low peak flow in morning
Obstructive spirometry pattern = FEV1/FEV < 70%
Improvement by 12% with an inhaler
Low PEFR

26
Q

What signs/symptoms do you see in a severe asthma attack?

A

Tachycardia
Hyper-expanded chest
Severe dyspnoea
Wheezing

27
Q

In an asthma attack, what signs are a very bad sign?

A

Silent chest

Bradycardia

28
Q

What are the different types of asthma?

A

Intrinsic - older onset, not obvious cause, more persistent, ?infection, exercise, stress, obesity

Extrinsic - Occupational
- Ectopic (IgE mediated)

29
Q

What type of hypersensitivity reaction is seen in ectopic asthma?

A

Type 1 hypersensitivity

Against aeroallergens

30
Q

What structural changes can be seen in asthma?

A
Loss of ciliated epithelium
increased mucous production
Thickening of basement membrane
Fibroblast activation
Smooth muscle hyper-responsiveness + hypertrophy
31
Q

Describe the immune mechanism of asthma pathophysiology.

A

Allergen lands on airway epithelium
Dendritic cell beneath detects it
Presents it to a naive Th cell
The Th cell then differentiates, in asthma more Th2 are formed rather than Th1 (non atopic response)Th2 stimulate atopic response- B cells + Plasma cells produce IgE- Mast cell degranulation (stimulated by IgE and IL-4 + 5)- Eosinophil - releases proteins (IL-5 stimulated)-> Bronchoconstriction

32
Q

What is released in mast cell degranulation?

A
Histamine
Serotonin
Cytokines
Leukotriene
IL-5- Cause bronchoconstriction and mucous secretion
33
Q

What factor in the immune response in asthma is directly related to the severity of asthma a pt has?

A

Eosinophil number

34
Q

What is the sequence of an asthmatic response to an allergen?

A

Early phase - rapid
Wheeze and cough
Mast cell degranulation

Late phase - hours after medication helps early symptoms-
Symptoms reoccur- Infiltration of immune cells: eosinophils, basophils, lymphocytes, macrophages - cause epithelial damage and inflammation - Bronchoconstriction again

35
Q

What are the steps in Asthma treatment?

A
1st - SABA
2nd - Add inhaled Corticosteroid
3rd - LABA (must be with steroid)
4th - Leukotrienes or Xanthines
5th - Add oral steroid - specialist help
36
Q

Name examples of SABAs.How do they work?

A

Salbutamol
Terbutaline
Increase cAMP - relax bronchial smooth muscle - inhibits release of inflam mediators- helps mucous clearance

37
Q

What side effects do SABAs have?

A

Tremor
Tachycardia
Low K+

38
Q

Name examples of inhaled corticosteroids.How do they work?

A
Beclometasone
Fluticasone
Budesonide
Reduce immune cell infiltration + inflam mediators
Reduces vascular permiability
39
Q

What side effects do inhaled corticosteroids have?

A

Local: oral candida, hoarse voice, sore throat
LT: osteopososis, infection risk, increased blood glucose, increase weight, reduce growth

40
Q

Name examples of LABAs.How do they work?

A

Salmetrol, Formetrol
Prolonged action due to lipid side chain
Relax bronchial smooth muscle

41
Q

Who can’t use LABAs?

A

Under 5s

Must be taken with steroid

42
Q

Name examples of Leukotrionine receptor antagonistsHow do they work?

A

Montelukast
Zafirlukast
Block leukotriene receptor on mast cells - reduce activation - reduce wheeze + bronchoconstriction and mucous

43
Q

Who are leukotriene receptor antagonists particularly useful for?

A
Atopics
Hayfever
Exercise triggered
Nocturnal
NSAID sensitive
44
Q

Name examples of XanthinesHow do they work?

A

Theophylline
Aminophyline
Inhibit phosphodiesterase which breaks down cAMP so increases cAMP - relaxes muscle + reduces inflam mediators

45
Q

What is the risk with Xanthines?

A

Has a narror theraputic range
Half life varies with other factors:- increases with : Cirrhosis, pul oedema, macrolides- decreases with : smoking, rafampicin

46
Q

What are the side effects of Xanthines?

A

Nausea + vomiting
tachycardia
convulsions
coma!

47
Q

What are some other possible drug treatments of Asthma, not on the step wise approach / used in specialist care?

A

Omalizumab - anti IgE antibody
Mepoluzimab - humanised monoclonal antibody against IL-5 - less eosinophil activation
Antimuscarinics - acute attack
IV magnesium sulphate - Acute attack
Chromones - sodium chromoglicate - old fashioned, stabilised mast cells