Mod12: Hypersensitivity Flashcards
Hypersensitivity allergic reactions
Which Type of hypersentitivity reaction is immediate?
Type I (immediate)
Hypersensitivity allergic reactions
In which type of Hypersensitivity allergic reaction do antigens crosslink with IgE antibodies?
Type I Hypersensitivity allergic reaction
Hypersensitivity allergic reactions
In Type I Hypersensitivity allergic reactions, the realease of with substances is triggered by the cross sensitivity of antigens with IgE antibodies?
Inflammatory mediators from mast cells
Hypersensitivity allergic reactions
What are examples of Type I Hypersensitivity allergic reactions?
Atopy
(Atopy: heightened immune responses to common allergens)
Urticaria-angioedema
True anaphylaxis!!!
Hypersensitivity allergic reactions - Type I
Which two subcategories is Type I hypersensitivity allergic reactions further subdivided into?
Atopic type I
Nonatopic type I
Hypersensitivity allergic reactions - Type I
Type I hypersensitivity allergic reactions that are IgE mediated, an that only affect the skin and respiratory tract are categorized as:
Atopic type I hypersensitivity allergic reactions
Include allergic rhinitis, dermatitis, and asthma
Hypersensitivity allergic reactions - Type I
Mild, Nonatopic type I hypersensitivity allergic reactions manifest as:
Urticaria
Angioedema
Hypersensitivity allergic reactions - Type I
Severe, Nonatopic type I hypersensitivity allergic reactions manifest as:
Anaphylaxis
This is when the IgE antibodies crosslink with the antigens
Massive inflammtory mediators will be released from the mast cells
Hypersensitivity allergic reactions - Hypersensitivity
Cytotoxic reactions are classified as which type of Hypersensitivity allergic reactions?
Type II hypersensitivity allergic reactions
Hypersensitivity allergic reactions - Hypersensitivity
Which antibodies mediate Type II (cytotoxic) hypersensitivity allergic reactions?
IgG antibodies
IgG bind to antigens on cell surface
Hypersensitivity allergic reactions - Hypersensitivity
In Type II (cytotoxic) hypersensitivity allergic reactions, what happens next after the IgG bind to antigens on cell surface
Activate classic complement pathway,
which causes cells Lysis
Hypersensitivity allergic reactions - Hypersensitivity
What are examples of Type II (cytotoxic) hypersensitivity allergic reactions?
Hemolytic transfusion reactions
Autoimmune hemolytic anemia
Heparin-induced thrombocytopenia
Hypersensitivity allergic reactions - Hypersensitivity
Which type of Hypersensitivity allergic reactions are immune complex hypersensitivity reactions calssified as:
Type III (immune complex) hypersensitivity reactions
Hypersensitivity allergic reactions - Hypersensitivity
In Type III (immune complex) hypersensitivity reactions, which complexes deposit in body tissues?
Antigen-antibody (IgG or IgM)
Hypersensitivity allergic reactions - Hypersensitivity
Which antibodies comprise the Antigen-antibody complexes responsible for Type III (immune complex) hypersensitivity reactions?
IgG or IgM
Hypersensitivity allergic reactions - Hypersensitivity
In Type III (immune complex) hypersensitivity reactions, what happens after antigen-antibody (IgG or IgM) complexes deposit in tissue?
Attract neutrophils to area
Release lysosomal enzymes and toxic products
Hypersensitivity allergic reactions - Hypersensitivity
Which are examples of Type III (immune complex) hypersensitivity reactions?
Arthus reaction
Serum sickness
Acute hypersensitivity pneumonitis
Hypersensitivity allergic reactions - Hypersensitivity
Delayed, cell mediated Hypersensitivity allergic reactions are classified as:
Type IV (Delayed, cell mediated) hypersensitivity allergic reactions
Hypersensitivity allergic reactions - Hypersensitivity
Which cells mediate Type IV (Delayed, cell mediated) hypersensitivity allergic reactions?
CD4+ T lymphocytes
Hypersensitivity allergic reactions - Hypersensitivity
How are pt’s sensitized for Type IV hypersensitivity allergic reactions?
Prior exposure
Hypersensitivity allergic reactions - Hypersensitivity
What are examples of Type IV (Delayed, cell mediated) hypersensitivity allergic reactions?
Contact dermatitis
Tuberculin-type hypersensitivity
Chronic hypersensitivity pneumonitis
Hypersensitivity allergic reactions - Four point severity scale
On the Four point severity scale, in which grade do hypersensitivity allergic reactions manifest as cutaneous signs, generalized erythema, urticaria, angioedema fall?
Grade I
(e.g., poision IV, surface hypersensitivity allergic reactions)
Hypersensitivity allergic reactions - Four point severity scale
On the the Four point severity scale, in which grade do hypersensitivity allergic reactions manifest as significant but not life threatening symptoms (e.g., cutaneous signs, hypotension, tachycardia, respiratory difficulty)?
Grade II
Hypersensitivity allergic reactions - Four point severity scale
In which grade on the four point severity scale do hypersensitivity allergic reactions manifest as Life threatening symptoms (e.g., arrhythmias, bronchospasm, cardiovascular collapse)
Grade III
(What to do: look for epi pen, call 911. etc.)
Hypersensitivity allergic reactions - Four point severity scale
In which grade on the four point severity scale do hypersensitivity allergic reactions manifest as cardiac and/or respiratory arrest or DEATH
Grade IV
Anaphylactic vs Anaphylactoid Reactions
True or False: Anaphylactoid are less severe reactions
True
Anaphylactic vs Anaphylactoid Reactions
What percentage of patients with anaphylactoid reactions will have Grade I reactions?
60%
Anaphylactic vs Anaphylactoid Reactions
What percentage of patients with anaphylactoid reactions will have Grade II reactions?
26%
Anaphylactic vs Anaphylactoid Reactions
What percentage of patients with anaphylactoid reactions will have Grade III reactions?
15%
Anaphylactic vs Anaphylactoid Reactions
True or False: incidence of anaphylactoid reactions decreases as their severity increases
True
60% of patients have Grade I reactions
26% of patients have Grade II reactions
15% of patients have Grade III reactions
Anaphylactic vs Anaphylactoid Reactions
True or False: Anaphylaxis more common as clinical severity increases
True
Anaphylactic vs Anaphylactoid Reactions
What percentage of patients with anaphylactic reactions will have Grade I reactions?
13%
Anaphylactic vs Anaphylactoid Reactions
What percentage of patients with anaphylactic reactions will have Grade II reactions?
22%
Anaphylactic vs Anaphylactoid Reactions
What percentage of patients with anaphylactic reactions will have Grade III reactions?
60%
Anaphylactic vs Anaphylactoid Reactions
What percentage of patients with anaphylactic reactions will have Grade IV reactions?
2%
Anaphylactic vs Anaphylactoid Reactions
What’s the severity Grade of most anaphylactic reactions?
Grade III
Anaphylactic vs Anaphylactoid Reactions
What causes the significant hypotension and the the tachycardia that we see in Anaphylactic and Anaphylactoid Reactions?
Significant Hypotension is from
Profound vasodilatation, leading to:
- Decreased venous return*
- Cardiac output falls*
- Increased heart rate (in response)*
Anaphylactic vs Anaphylactoid Reactions
What causes the edema that we see in Anaphylactic and Anaphylactoid Reactions?
Acute changes in vascular permeability
Fluid moves into interstitial spaces
Anaphylactic vs Anaphylactoid Reactions
Along with the bronchospasm, what other pulmonary manifestation accompany Anaphylactic and Anaphylactoid Reactions?
Bronchial hyperactivity
Anaphylactic vs Anaphylactoid Reactions
What causes the bronchial edema that we see in Anaphylactic and Anaphylactoid Reactions?
The mediators that are being released throughout the body
Anaphylactic vs Anaphylactoid Reactions
What causes the alveolar hypoventilation that we see in Anaphylactic and Anaphylactoid Reactions?
Bronchospasm closing the airway
Decreased gas exchange
Anaphylactic vs Anaphylactoid Reactions
What causes the hypoxemia that we see in Anaphylactic and Anaphylactoid Reactions? What does it lead to?
Hypoventilation
Decreased gas exchange
Leads to
Respiratory & metabolic acidosis
Decreased mixed venous O2 saturation
Anaphylactic vs Anaphylactoid Reactions
What causes the acute respiratory distress that we see in Anaphylactic and Anaphylactoid Reactions? What does it lead to?
Huge V/Q mismatch
Decreased ventilation
Anaphylactic vs Anaphylactoid Reactions
What’s the most frequent causes of death in anaphylactic reactions?
Laryngeal edema
(Gas exchange becomes so low that it leads to a global hypoxic event)
Cardiovascular collapse
Anaphylactic vs Anaphylactoid Reactions
What are anesthesia most important interventions to prevent death from an anaphylactic reaction?
Protect the airway
Prevents the laryngeal edema
Treat cardiovascular collapse
