Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Anat 1082 Multiple Choice Revision > Anaphylaxis > Flashcards

Anaphylaxis Flashcards

1
Q

How do you characterise anaphylaxis?

A

The RCUK (resuscitation council uk 🇬🇧) characterise it as life threatening problems involving the:

  • Airway oedema
  • Breathing - Bronchospasm ( spasm/ contraction of the airway) - tachypnoea (rapid breathing)
  • Circulation - Tachycardia
  • skin and mucosal changes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is biphasic anaphylaxis?

A
  • After complete recovery from anaphylaxis a recurrence of symptoms within 72 hours with no further exposure to the antigen.
  • It is managed in the same way as anaphylaxis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is Idiopathic anaphylaxis?

A

Where no identifiable tumulus can be found all known causes of anaphylaxis must be excluded before this diagnosis can be made.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

5 examples of relevance…. GO

A
  • Literature generally suggests that anaphylaxis is increasing in the general population.
  • An alteration in immunological status due to the increased progesterone level during pregnancy may predispose pregnant women to anaphylaxis
  • Anaphylaxis is seen more in children with an estimated 1 in 170 children compare to 30 per 100000 adults
  • Food is common trigger in children, where as medicinal products in adults are a more common trigger
  • Approx 20 deaths a year from anaphylaxis in the UK 🇬🇧 from anaphylaxis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the potential causes of anaphylaxis?

A

In theory any food glycoproteins can cause an anaphylaxis.

  • The majority of anaphylaxis reactions are caused by the immune system responding to the protein antigens.
  • So anything that has a high level if protein can be a potential risk factor for life threatening anaphylactic reactions

Examples of food with high protein.

  • Eggs
  • Nuts
  • Milk
  • Fruit and veg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is catamenial anaphylaxis?

A

This is a syndrome of hypersensitivity induced by endogenous progesterone secretion. Patients may experience a cyclic pattern of attacks during the pre- menstrual part of the cycle

  • Occurs in women
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 5 Co- factors that amplify anaphylaxis?

A 
1-  Exercise 
2- Acute infection ie cold or fever
3- Emotional stress
4- Disruption of routine ie travel 
5- Pre menstrual status (female only)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Explain the time course for fatal anaphylaxis… GO

A
  • When anaphylaxis is fatal death usually occurs very soon after the contact with the trigger.
    Fatal food reactions- causes respiratory arrest after 30-35 mins
    Insect stings - 10-15 mins
    Intravenous medication after 5 mins.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When does anaphylaxis occur?

A

It occurs when a foreign antigen (primarily proteins) causes an immunological response from an individual leading to the release of histamines and other substances causing systematic symptoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Who is at risk of anaphylaxis?

A
  • Anaphylaxis is driven by immunoglobulin E (IgE)
  • some people are referred to as being ATOPIC
  • This means they have an increased level of IgE in their immune system.
  • The increase in IgE manifests via conditions such as eczema, hay fever, asthma and anaphylaxis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the pathophysiology pathway for anaphylaxis?

A
  • Antigen enters the body
  • Antigen attaches its self to mast and basophil cells (both white cells)
  • The body now produces IgE antibodies
  • Antibodies are used by the immune system to identify and destroy antigens
  • The body now has a primary response
  • A memory is laid down
  • The person is now referred to as being sensitised
  • These changes take place at a cellular level
  • On the second contact to the antigen after someone has become sensitised.
  • Mast and basophil cells will degranulate / rupture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the substances released by the mast and basophil cells when they rupture?

A
  • Heparin (anticoagulant)
  • Histamine ( vasodilator + increases tissue permeability)
  • Serotonin ( bronchoconstrictor)
  • Platelet activating factor (clotting)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Histamine acts on the H1 and H2 receptors (found in blood vessels)
What are the adverse effects of histamine?

A
  • Hypotension
  • Tachycardia
  • Bronchospasm
  • Angioedema ( deep muscle swelling)
  • Increased acidity
  • Flushing
  • Itching
  • Hypotension (low BP)
  • Plasma extravasation into the tissues causing hypovolaemic shock(loss of water )
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does hypovolaemic shock develop in anaphylaxis?

A
  • Activation of the H1 and H2 receptors caused by histamine
  • Allows waste to move out of the capillary and into the tissues.
  • This results in fluid loss And ultimately hypovolaemic shock.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why does your heart rate increase when your BP falls

A
  • Drop in BP
  • Baroreceptors in cardiovascular 🫀 system pick up three change in BP
  • The baroreceptors send impulses to the medulla oblongata
  • The medulla oblongata send impulses to the Vegas nerve (release the brake)
  • The heart rate subsequently increases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why does your BP fall in anaphylactic shock?

A
  • Your Bp falls because of vasodilation and increased tissue permeability because of the release of histamine.
  • So the trigger for causing low BP is histamine
17
Q

MEGA PRINCIPLE 5

What can happen when your BP falls in relation to O2?

A
  • When your BP falls the potential level of O2 to the brain can fall because the amount of blood 🩸 travelling to the brain 🧠 has decreased.
  • this can cause confusion, loss of consciousness, starvation of O2 from the brain
18
Q

MEGA PRINCIPLE 6

What can happen when your BP falls in relation to the kidneys?

A
  • When BP falls the perfusion of blood 🩸 to your kidneys can fall.
  • Our kidneys then consider you as dehydrated and will initiate a hormone release such as antidiuretic hormone or aldosterone.
  • Meaning the urine output will be reduced.
19
Q

What does serotonin do during anaphylaxis?

A

It causes either vasoconstriction (especially in renal vessels) or vasodilation.

  • Causes venous constriction
  • Promotes platelet activation
  • Increases capillary permeability
  • Causes bronchoconstriction
  • It is also an important molecule involved in pain transmission
20
Q

MEGA PRINCIPLE 7

What happens when your BP falls in relation to respiratory system?

A
  • When BP falls the resp system bronchoconstricts
  • This means O2 uptake may fall and that may mean because Hoyt not delivering or taking in as much O2
  • You have to switch form aerobic to anaerobic respiration.
  • A consequence of this is the production of lactate acid and your Ph will fall.
  • When your Ph falls the resp rate increases.
  • The chemoreceptor send impulses medulla oblongata
  • The medulla oblongata sends impulses to the phrenic nerve
  • The phrenic nerve controls the lungs 🫁 and makes the resp rate increase in an effort to get rid of the excess CO2 which acts like an acid
21
Q

What does Platelet activating factor (PAF) do?

A
  • PAF is a potent activator and mediator of many leukocytes functions including:
  • Platelet aggregation
  • Degranulation/ rupture
  • Inflammation
  • Anaphylaxis
22
Q

What is tryptase and how can a mast cell tryptase test help diagnose anaphylaxis?

A
  • Tryptase is an enzymes released by mast and basophil cells during an anaphylactic reaction.
  • Mature tryptase shows mast cell degranulation and is elevated in a systematic reaction.
  • Currently we only test for total tryptase
  • Tryptase is realised in 30- 60 mins following activation and its half life is - 2 hours allowing a longer test window
  • levels above 10-11.4 ng/ml are consistent with anaphylaxis
23
Q

How do you conduct a mast cell tryptase test?

A
  • After a suspected anaphylactic reaction in people over 16. Take timed blood samples for the mast tryptase testing as follows:
  • 1st sample as as possible after the emergency treatment has started
  • 2nd sample ideally within 1-2 hours (but no later the 4 from the onset of symptoms (NICE 2011)
24
Q

Where are mast and basophil cells found?

A
  • The respiratory 🫁 system
  • Cardiovascular 🫀 system
  • Gastrointestinal system
  • Skin
25
Q

What are the 5 products of mast cell activation?

A 
1- Histamine
2- Proteoglycans 
3- Cytokines ( IL-4, IL-5, IL-6, IL-8, IL-13, TNF, Fibroblasts, Growth factor stem cell factor
4- Lipid mediators 
5- Protease
26
Q

What are the 6 products of basophil activation?

A 
1- Protease 
2- Proteoglycans
3- Cytokines (IL-4, IL-8, IL-13, IgE etc)
4- Lipid mediator 
5- Basic protein 
6- Histamine
27
Q

What does adrenaline do?

A
  • Releases smooth muscle contraction,
  • Increases heart muscle contraction
  • Causes vasoconstriction systematically (improving BP)
  • Causes bronchiole dilation ( making breathing easier)
28
Q

why can pregnant women not have adrenaline?

A
  • It can cause uterine vasoconstriction which results in hypoxic damage to the fetus
  • However mums survival takes priority.
29
Q

How do we give adrenaline?

A

Adrenaline is given intramuscularly every five mins if no improvement is seen.

Anat 1082 Multiple Choice Revision (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions