Allergies and Anesthesia Flashcards Preview

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Flashcards in Allergies and Anesthesia Deck (57)
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1
Q

Will add

A

Love you all

2
Q

What is an allergy?

A

Reproducible adverse reaction to an extrinsic substance mediated by the immune system

3
Q

What are the 4 types of allergic reactions?

A

Type 1: immediate
Type 2: cytotoxic
Type 3: immune complex
Type 4: delayed

4
Q

What are some examples of type 1 reaction?

A
    • Atopy
    • Urticaria (hives)
    • Angioedema (swelling)
    • Anaphylaxis
5
Q

What type of reactions occur because of hemolytic reactions or HIT ?

A

Type 2 (cytotoxic)

6
Q

What are some examples of type 3 reaction?

A

Serum sickness

– reaction to an injection of foreign proteins

7
Q

What are some examples of type 4 reaction?

A

Contact dermatitis

– skin reaction because of direct contact with a substance

8
Q

What is anaphylaxis?

A

An exaggerated response to a foreign substance that is mediated by an antigen-antibody reaction

9
Q

What is the onset of an anaphylactic reaction?

A

Minutes

10
Q

What is it about an anaphylactic reaction that makes it unique?

A

It requires a previous exposure to antigen to have a reaction

11
Q

What is the one most common feature of an anaphylactic reaction that makes it deadly?

A

Circulatory collapse

12
Q

What is the incidence and mortality rates for an anaphylactic reaction?

A

1:5000

Mortality 6%

13
Q

What is the mechanism of an allergic reaction?

A
    • Antigen causes stimulation of IgE antibodies
    • Antibodies fix to mass cells and basophils
    • 2nd exposure of antigen results in antibody binding onto mass cells/basophils
    • Binding stimulates degranulation and release of chemical mediators
14
Q

What are the most common chemical mediators released from mass cells/basophils?

A
  • -Histamine
  • -Leukotriene
    • Prostaglandins
15
Q

What does histamine release cause?

A
    • Increased capillary permeability
    • Peripheral vasodilation
    • Bronchoconstriction
16
Q

What does leukotriene release cause?

A
    • Bronchoconstriction
    • Increased capillary permeability
    • Negative iontropy
17
Q

What does prostaglandins release cause?

A
    • Bronchoconstriction

- - Vasodilation

18
Q

What resembles anaphylaxis but is not mediated by the immune system and does not involve IgE antibodies?

A

Anaphylactoid reactions

19
Q

With anaphylactoid reactions, what is the most often cause?

A

Pharmacologic

– Drug has direct action on mast cells/basophils to release large amounts of histamine

20
Q

Can an anaphylactoid reaction occur on 1st exposure?

A

YES

21
Q

T OR F

Anaphylactoid reactions clinically are indistinguishable from anaphylactic reactions and are equally life-threatening?

A

TRUE

22
Q

What are some predisposing factors for anaphylactoid reactions?

A
    • Pregnancy
    • Youth (peds)
    • History of atopy
23
Q

Under anesthesia, what are some clinical signs your patient is having some sort of reaction?

A
    • Circulatory collapse
    • Pulmonary insults
    • Cutaneous signs
24
Q

What are some indications of circulatory collapse?

A
    • Profound Vasodilation secondary to decreased SVR
    • Profound hypotension that difficult to fix
    • Tachycardia
    • Pulmonary vasoconstriction / HTN
    • End result, cardiac arrest
25
Q

What are some of the pulmonary insults that can present?

A
    • Wheezing (heard throughout chest)
    • Severe bronchospasm
    • Increased PIP
    • Laryngeal edema and/or stridor
    • Pulmonary edema
    • Acute respiratory failure / hypoxia
26
Q

What are some of the signs you can see on the skin?

A
    • Uticaria (hives)
    • Flushing
    • Periorbital edema
    • Perioral edema
27
Q

What are the basics once a reaction has been identified?

A
    • Reactions vary in severity and clinical manifestations
    • IMMEDIATE recognition and treatment is a must
    • AVOID worst case scenario: DEATH
28
Q

What are treatment options/plan of care once a reaction has been identified?

A
    • Stop administration of antigen
    • 100% O2 and PPV
    • Discontinue volatile agents
    • Intravascular volume expansion
    • Epinephrine
    • If needed, external cardiac massage (chest compressions)
29
Q

When giving intravascular volume expanders, is it better to give colloids or crystalloids?

A

– Colloids

because of increased capillary permeability colloids stay in vascular longer

30
Q

What is the dose for giving intravascular volume expanders?

A

20 mg/kg boluses

Total: 1-4 L

31
Q

What dose of epi do you administer?

A

1:10,000
@ 0.1 mL/kg IV
== repeat dose every 3-5 min doubling the 2nd dose

32
Q

How does epi help in treating anaphylactic shock?

A
    • B2 agonist effect relaxes bronchial smooth muscle

- - A agonist effect vasoconstricts blood vessels

33
Q

Once patient has stabilized, what are some secondary treatment options?

    • Drug and dose
    • What it treats/does/is in parentheses
A
    • Diphenhydramine 0.25-1 mg/kg (Antihistamine)
    • Hydrocortisone 8 mg/kg (Corticosteroid)
    • Albuterol ( Inhaled bronchodilator)
    • Aminophylline (Bronchospasm)
    • Bicarb (as needed for acidosis)
    • Inotrope infusion as needed for BP
34
Q

What are some immediate post-op management goals after a reaction?

A
    • Admit to ICU
    • Clotting screen and blood gases
    • Airway evaluation before extubation
35
Q

What are the different types of skin test available for reactions?

A
    • Intradermal
    • RAST (radioallergosorbent test)
    • ELISA (enzyme linked immunosorbent assay)
36
Q

What is difference in RAST and ELISA?

A
    • RAST tests patient serum against specific IgE antibodies

- - ELISA measures antigen specific antibodies

37
Q

What are some common offenders of causing reactions in the OR?

A
    • Muscle relaxants (most common)
    • Induction drugs
    • LA
    • Opioids
    • Antibiotics
    • Latex
    • Halothane and others
38
Q

What are 2 most common muscle relaxants to cause reactions?

A
    • Succ

- - Atracurium

39
Q

T OR F

There is a cross reactivity between sux and ND muscle relaxants?

A

TRUE

40
Q

What is the unique thing with reactions and induction drugs?

A

Anaphylaxis may occur even after previous uneventful drug exposure

41
Q

Do the barbiturates cause reactions?

A

Very rare, but when they do occur very life threatening

42
Q

Are patients truly allergic to propofol?

A

Not likely, most likely due to other allergies (egg, soy, etc)

43
Q

What is true with LA(local anesthetics) and reactions?

A

True allergic reactions rare

Most reactions are just adverse effects

44
Q

Are esters or amides more likely to cause the reaction?

A

Esters because they are metabolized by PABA

45
Q

What is the main opioid reaction we are concerned with?

A

Morphine

causes direct histamine release along with arterial and venous dilation

46
Q

What is the only class of drug that brings about true anaphylaxis reactions?

A

Antibiotics

47
Q

What is the cross sensitivity of PCN and cephalosporins (ancef)?

A

1-2%

but still err on side of caution

48
Q

Vancomycin produces which type of reaction?

A
    • Produces both

- - However anaphylactoid most common and causes redman’s syndrome

49
Q

What is the only anaphylactic reaction that has delayed onset?

A

Latex

50
Q

What is the time frame before you will begin to see symptoms?

A

30-40 min after exposure

51
Q

What are the high-risk patient populations that may have cross sensitivity to latex?

A
    • Spina bifida

- - Healthcare workers

52
Q

Halothane has a direct correlation to what adverse outcome?

A

Hepatitis

53
Q

What are some allergic symptoms brought on by halothane?

A

–Eosinophilia
–Rash
–Fever
(Prior exposure to halothane increases these risks)

54
Q

What are other things that can cause a reaction?

A
    • Blood products (around 3%)
    • IV Contrast
    • Protamine
    • High risk patient population (allergy to seafood, diabetic)
55
Q

T OR F

True anaphylaxis is rare when given anesthetic agents

A

TRUE

56
Q

T OR F

Anaphylactoid reactions occur much more commonly?

A

TRUE

57
Q

What is the key to preventing death when your patient has a reaction?

A
    • Have a high index of suspicion
    • Prompt recognition
    • Aggressive treatment