Family Nurse Practitoner Concept Map

Anaphylaxis

Etiology

Labs/ Diagnostics

Pathophysiology

Physical Findings

Treatment

Complications

Immune system response

IgE-Mediated Response

primarily driven by an overreaction of the immune system to an allergen (Yu & Lin, 2015)

When a person who is sensitized to a

particular allergen is exposed to it, their

immune system releases large amounts of histamine and other chemicals from mast

cells and basophils. This cascade of reactions

leads to the symptoms associated with

anaphylaxis (Yu & Lin, 2015)

The most common mechanism involves

Immunoglobulin E (IgE) antibodies. These

antibodies are produced by the immune system

in response to an allergen. When the

allergen is encountered again, it binds to IgE

antibodies on mast cells and basophils,

triggering the release of histamine and other

inflammatory mediators (Yu & Lin,

2015)

Common Causes

Foods

Insect Bites

Medications

Latex

Exercise Induced

Other Triggers

Nuts, Shellfish, Fish, Milk, Eggs, Soy, Wheat,

etc.

Bees, Wasps, Hornets, Yellowjackets, etc.

Antibiotics, NSAIDs, Anesthetics, etc.

Natural rubber latex found in items such as gloves, balloons, and

certain medical devices

Exercise can trigger anaphylaxis in some

individuals, particularly when combined with certain foods or other

allergens

Contrast dues used in medical imaging,

medical procedures, vaccinations

Prevalence

General Population

Food Allergies

Insect Stings

Medication-Induced

Exercise-Induced

Incidence of anaphylaxis ranges

from 1 to 5 cases per 100,000 people annually

(Yu & Lin, 2015)

Severe food-induced anaphylaxis in the US is estimated to be around

0.1% to 0.2% of the population (Yu & Lin,

2015)

Higher rate of food related anaphylaxis

seen in children

30%-60% of anaphylaxis cases caused by insect stings (Yu & Lin, 2015)

In the US, up to 10% of anaphylactic cases

caused from medication. Less

common (Yu & Lin, 2015)

Rare, but severe. 0.01% to 0.2% of anaphylaxis

is exercise-induced

In the United States and Canada, anaphylaxis is

a recognized health concern with increasing

awareness and reporting. Estimates

suggest that approximately 1 in 50 children and 1 in 200

adults have experienced

anaphylaxis related to food allergies (Yu & Lin,

2015).

In Europe, the prevalence of

anaphylaxis varies by country. For example,

the prevalence of food- induced anaphylaxis in

the UK is about 1 in 1000 individuals.

European studies also indicate that insect

stings are a common trigger (Yu & Lin, 2015)

Australia has one of the highest rates of food

allergies and anaphylaxis. Estimates suggest that around 1

in 100 children experience food-

induced anaphylaxis. The prevalence may be higher due to increased

awareness and reporting (Yu & Lin,

2015)

Morbidity & Mortality

Anaphylaxis typically presents rapidly, often

within minutes of exposure to an allergen. Symptoms can include

difficulty breathing, swelling of the face and

throat, hives, abdominal pain,

vomiting, and dizziness. Complications: If not

treated promptly, anaphylaxis can lead to serious (Anaphylaxis - Symptoms & Causes -

Mayo Clinic, 2021)

If not treated promptly anaphylaxis can lead to serious complications

Respiratory Distress: Severe difficulty breathing due to

swelling of the airways or bronchoconstriction.

Cardiovascular Effects: Drop in blood pressure, hypotension, rapid or

irregular heartbeat, and shock

Neurological Effects: Confusion, loss of consciousness, or

seizures due to severe hypotension or hypoxia.

Organ Damage: Prolonged anaphylaxis

can affect multiple organs, potentially

leading to complications such as acute kidney injury or

liver dysfunction.

Fatal Outcomes: Anaphylaxis is life- threatening and, if

untreated, can lead to death. The mortality

rate is relatively low but significant. Estimates

suggest that the mortality rate from anaphylaxis ranges

from 0.1% to 0.2% in the general population.

However, this rate can vary based on several factors (Anaphylaxis - Symptoms & Causes -

Mayo Clinic, 2021)

Timeliness of Treatment: Immediate

administration of epinephrine is crucial.

Delayed treatment increases the risk of

severe outcomes and death.

Severity of Reaction: Individuals

experiencing severe anaphylaxis, with rapid

onset and multiple organ involvement, are

at higher risk of mortality.

Access to Medical Care: Availability of

emergency medical services and access to

treatment can influence outcomes. In regions

with limited healthcare resources, mortality rates may be higher.

Skin

Respiratory System

Cardiovascular System

Gastrointestinal System

Neurological System

General Appearance

Urticaria (Hives): Raised, itchy welts or rash, often appearing

suddenly. These can be widespread or localized (Anaphylaxis | Causes,

Symptoms & Treatment | ACAAI Public Website,

2022).

Angioedema: Swelling of deeper layers of the

skin, particularly in areas like the face, lips, tongue, and throat. This

swelling can lead to difficulty breathing if it

affects the airways (Anaphylaxis | Causes,

Symptoms & Treatment | ACAAI Public Website,

2022).

Stridor: High-pitched, wheezing sound heard

on inhalation, indicating upper airway

obstruction due to swelling (Anaphylaxis |

Causes, Symptoms & Treatment | ACAAI

Public Website, 2022).

Wheezing: High-pitched whistling sound during exhalation, signifying

bronchospasm or constriction of the

lower airways (Anaphylaxis | Causes,

Symptoms & Treatment | ACAAI Public Website,

2022).

Respiratory Distress: Signs of labored

breathing, such as use of accessory muscles,

nasal flaring, or tachypnea (rapid

breathing) (Anaphylaxis | Causes, Symptoms &

Treatment | ACAAI Public Website, 2022).

Cyanosis: Bluish discoloration of the lips,

face, or extremities, suggesting hypoxia or

inadequate oxygenation

(Anaphylaxis | Causes, Symptoms & Treatment | ACAAI Public Website,

2022).

Abdominal Pain: Crampy or diffuse pain, often accompanied by nausea, vomiting, or

diarrhea. These symptoms arise from

gastrointestinal mucosal edema and increased motility

(Anaphylaxis | Causes, Symptoms & Treatment | ACAAI Public Website,

2022).

Confusion or Altered Mental Status: Due to severe hypotension or

hypoxia, which may present as

disorientation, confusion, or loss of

consciousness (Anaphylaxis | Causes,

Symptoms & Treatment | ACAAI Public Website,

2022).

Hypotension: Low blood pressure, which can be

measured as a significant drop from

baseline or observed as dizziness or fainting

(Anaphylaxis | Causes, Symptoms & Treatment | ACAAI Public Website,

2022).

Tachycardia: Rapid heart rate, often

exceeding 100 beats per minute, as the body

compensates for reduced blood pressure (Anaphylaxis | Causes,

Symptoms & Treatment | ACAAI Public Website,

2022).

Weak Pulse: A weak or thready pulse may

indicate severe hypotension or shock

(Anaphylaxis | Causes, Symptoms & Treatment | ACAAI Public Website,

2022).

Restlessness or Agitation: Patients may

appear anxious or distressed due to

difficulty breathing or a sense of impending

doom (Anaphylaxis | Causes, Symptoms & Treatment | ACAAI

Public Website, 2022).

Fatigue or Weakness: Associated with severe hypotension or shock,

patients may feel unusually weak or

lethargic Anaphylaxis | Causes, Symptoms & Treatment | ACAAI

Public Website, 2022)

In anaphylaxis, laboratory and

diagnostic tests can provide supportive

information but are not typically used for

immediate diagnosis, as anaphylaxis is primarily

diagnosed based on clinical presentation.

However, certain abnormalities and tests

can help in assessing the severity of the

reaction, monitoring the patient, and

identifying potential complications (Shaker

et al., 2020).

Tryptase: This enzyme is released from mast cells and is a useful

biomarker for diagnosing anaphylaxis.

Elevated serum tryptase levels are

often observed within 1-2 hours of the

reaction and can help confirm the diagnosis of

anaphylaxis. Normal levels do not rule out

anaphylaxis but elevated levels can

support the diagnosis. (Shaker et al., 2020)

Histamine: Histamine is another mediator

released during anaphylaxis. Elevated

plasma histamine levels can be measured, but

histamine is less stable and may not always be detectable depending on the timing of the

test and handling of the sample. (Shaker et al.,

2020)

Complete Blood Count

Electrolytes and Renal Function Tests

Arterial Blood Gas (ABG)

High lactate levels (2 mmol/L) can indicate

tissue hypoxia and are used to assess the

severity of shock or metabolic stress.

(Shaker et al., 2020)

Chest X-ray may be performed if there is

concern about complications such as pulmonary edema, but it is not routinely used

for diagnosing anaphylaxis. (Shaker et

al., 2020)

An ECG may be done to evaluate for cardiac

complications or arrhythmias, especially

in cases with severe hypotension or

suspected cardiovascular

involvement. (Shaker et al., 2020)

In severe cases, there might be proteinuria due to acute kidney

injury, shown through a urinalysis.( Shaker et

al., 2020)

Anaphylaxis is primarily diagnosed based on clinical history and

physical examination rather than laboratory

tests. Prompt recognition and

treatment are critical. (Shaker et al., 2020)

Laboratory tests are generally more useful

for follow-up and to assess the effects of

treatment rather than for immediate

diagnosis. (Shaker et al., 2020)

Serum tryptase levels should be measured within 1-2 hours of symptom onset for optimal accuracy, though levels can

remain elevated for up to 6-12 hours. (Shaker et

al., 2020)

An increase in eosinophils ( > 350)

might be observed in some cases, though it is

more indicative of a chronic allergic reaction

rather than acute anaphylaxis.(Shaker et

al., 2020)

An increase in white blood cell count (>

11,000) may be seen due to the inflammatory

response (Shaker et al., 2020)

Anaphylaxis can lead to metabolic changes such

as hypokalemia (low potassium, < 3.5) or

other electrolyte imbalances due to

vomiting, diarrhea, or altered fluid balance. (Shaker et al., 2020)

Kidney function tests (such as serum

creatinine) may be monitored to assess for

signs of acute kidney injury secondary to

severe hypotension or shock (Shaker et al.,

2020)

Metabolic acidosis may be present due to shock and hypoperfusion. pH of < 7.35 and a HCO3 < 22 (Shaker et al., 2020)

Oxygen saturation levels may be low (<

90%) if there is significant respiratory distress or hypoxemia

(Shaker et al., 2020)

Sensitization PhaseSensitization of Mast Cells and Basophils

Re-exposure to Allergen

Release of Mediators

Systemic Effects and Symptoms

Cellular Recruitment and Amplification

Clinical Manifestations

Resolution and Recovery

(During initial exposure to an allergen, the

immune system recognizes it as a

foreign substance. McLendon & Sternard,

2023)

Allergen-specific T- helper cells (Th2 cells) are activated. These

cells are crucial in orchestrating the immune response.

(McLendon & Sternard, 2023)

Activated Th2 cells stimulate B cells to

produce Immunoglobulin E (IgE)

antibodies specific to the allergen. These IgE

antibodies are produced and released into the

bloodstream. (McLendon & Sternard,

2023)

IgE antibodies bind to high-affinity FcεRI receptors on the

surface of mast cells and basophils. Mast cells are distributed

throughout connective tissues, while basophils circulate in the blood.

(McLendon & Sternard, 2023)

This binding sensitizes mast cells and

basophils, making them primed to respond to

subsequent exposures to the allergen.

(McLendon & Sternard, 2023)

On subsequent exposure, the allergen

cross-links the IgE antibodies on sensitized

mast cells and basophils. This cross-

linking is a key trigger for the anaphylactic

reaction. (McLendon & Sternard, 2023)

Cross-linking of IgE receptors causes mast cells and basophils to

degranulate, releasing a variety of preformed and newly synthesized mediators. (McLendon

& Sternard, 2023)

Released from granules, histamine causes

vasodilation, increased vascular permeability,

and contraction of smooth muscles (e.g., bronchoconstriction).

(McLendon & Sternard, 2023)

These lipid mediators contribute to

bronchoconstriction, increased vascular permeability, and

recruitment of inflammatory cells.

(McLendon & Sternard, 2023)

They contribute to inflammation,

vasodilation, and the sensation of pain.

(McLendon & Sternard, 2023)

Inflammatory cytokines such as TNF-alpha and

IL-4 are released, further promoting inflammation and

recruiting more immune cells.

(McLendon & Sternard, 2023)

Histamine and other mediators cause vasodilation and

increased permeability of blood vessels, leading to edema (swelling) and a drop in blood pressure

(hypotension). (McLendon & Sternard,

2023)

Bronchoconstriction caused by histamine

and leukotrienes leads to difficulty breathing, wheezing, and stridor. (McLendon & Sternard,

2023)

Increased smooth muscle contraction in the gastrointestinal

tract results in symptoms like

abdominal pain, nausea, vomiting, and diarrhea. (McLendon &

Sternard, 2023)

Urticaria (hives) and angioedema occur due

to fluid leakage into the skin tissues and the

release of inflammatory mediators. (McLendon

& Sternard, 2023)

Additional inflammatory cells,

such as eosinophils and neutrophils, are

recruited to the site of reaction, exacerbating

inflammation and tissue damage.

(McLendon & Sternard, 2023)

These recruited cells release additional

mediators, amplifying the inflammatory

response and contributing to the

severity of symptoms. (McLendon & Sternard,

2023)

The rapid release of mediators leads to

immediate symptoms such as swelling,

difficulty breathing, and a dramatic drop in

blood pressure. (McLendon & Sternard,

2023)

In some cases, a late- phase response occurs 2-4 hours after initial

exposure, characterized by prolonged

inflammation and continued symptoms.

(McLendon & Sternard, 2023)

Epinephrine (adrenaline) acts as a

counter-regulatory mediator. It causes vasoconstriction,

decreases vascular permeability, relaxes

bronchial smooth muscles, and stabilizes mast cells to prevent

further mediator release.

(McLendon & Sternard, 2023)

Other treatments, such as oxygen, intravenous

fluids, and antihistamines, may be

used to support recovery and manage symptoms. (McLendon

& Sternard, 2023)

Epinephrine

Positioning

Oxygen

Intravenous Fluids

Antihistamines

Corticosteroids

Monitoring

Education

Additional Considerations

Epinephrine is the first- line treatment for

anaphylaxis. It should be administered as

soon as anaphylaxis is suspected.

Route: Typically given intramuscularly (IM) in the mid-anterolateral thigh (vastus lateralis) for adults and children.

Dosage: Adults: 0.3 to 0.5 mg (0.3

to 0.5 mL of a 1:1000 solution).

Children: 0.01 mg/kg (up to a maximum of 0.3 mg) of a 1:1000 solution.

Frequency: Can be repeated every 5 to 15 minutes if symptoms

persist or worsen (McLendon & Sternard,

2023)

If the patient is conscious and

breathing, they should lie down with their legs

elevated to help improve blood flow and

counteract hypotension. If the

patient is having difficulty breathing, a

sitting or semi-reclining position may be

preferable (McLendon & Sternard, 2023)

Administer oxygen if the patient shows signs

of hypoxia or respiratory distress. This helps maintain

adequate oxygen levels in the blood (McLendon

& Sternard, 2023).

Administer IV fluids (e.g., normal saline) to manage hypotension and ensure adequate blood volume. This is

especially important if there are signs of shock

or dehydration (McLendon & Sternard,

2023).

Antihistamines ( diphenhydramine )

may be used to manage symptoms like itching and hives. However,

they are not a substitute for

epinephrine and should not delay its

administration (McLendon & Sternard,

2023).

Corticosteroids (prednisone or

hydrocortisone) can be given to reduce

inflammation and prevent late-phase reactions. They are

typically administered orally or intravenously but are not immediate

in their effects (McLendon & Sternard,

2023).

Patients should be monitored for at least 4

to 6 hours after an anaphylactic episode to

detect any potential biphasic reaction (a

recurrence of symptoms) or delayed symptoms. Regularly check blood pressure, heart rate, respiratory

rate, and oxygen saturation (McLendon &

Sternard, 2023).

Some patients may experience a biphasic

reaction, where symptoms return after

initial improvement. Close observation is essential to manage

this risk (McLendon & Sternard, 2023).

Educate the patient about identifying and

avoiding known allergens or triggers. Teach patients and

caregivers how to use an epinephrine auto- injector properly and

ensure they carry it at all times (McLendon &

Sternard, 2023).

Create a written action plan detailing steps to

take in case of an anaphylactic reaction. Include information on recognizing symptoms, using epinephrine, and

seeking emergency medical help (McLendon

& Sternard, 2023).

Referral to an allergist for allergy testing and

evaluation may be necessary to identify specific triggers and develop a long-term management plan.

Regular follow-up to review the patient’s

allergy management and adjust the action

plan as needed (McLendon & Sternard,

2023).

Ensure that schools, workplaces, and other

environments are aware of the patient’s

condition and have protocols in place for

managing anaphylaxis. When traveling, carry

emergency medications and inform travel

companions about the patient’s condition and

treatment plan. (McLendon & Sternard,

2023)

Maintain updated health records and

inform all healthcare providers about the patient’s history of

anaphylaxis and treatment needs

(McLendon & Sternard, 2023).

Respiatory

Cardiovascular

Gastrointestinal

Renal

Neurological

Cardiopulmonary Resuscitation (CPR)

Biphasic Anaphylaxis

Long-Term Effects

Inadequate Treatment

Upper Airway

Lower Airway

Swelling of the throat, tongue, or larynx can obstruct the airway, leading to difficulty

breathing and potential asphyxiation. (Fischer

et al., 2018)

A high-pitched sound indicative of upper

airway obstruction due to swelling (Fischer et

al., 2018).

Severe constriction of the bronchial tubes can

lead to wheezing, shortness of breath,

and respiratory distress (Fischer et al., 2018).

Anaphylaxis can trigger or worsen underlying

asthma, increasing the risk of persistent respiratory issues

(Fischer et al., 2018).

Due to significant fluid loss into the tissues (edema), leading to

decreased blood volume and low blood pressure

(Fischer et al., 2018).

Characterized by a rapid drop in blood pressure, leading to inadequate

perfusion of vital organs (Fischer et al.,

2018).

Severe anaphylaxis and associated hypoxia or electrolyte imbalances

can lead to cardiac arrhythmias (Fischer et

al., 2018).

Severe cases of anaphylaxis may cause

or exacerbate gastrointestinal bleeding due to

mucosal damage or stress (Fischer et al.,

2018).

Persistent pain or cramping may occur due to prolonged or

severe reactions affecting the

gastrointestinal tract (Fischer et al., 2018).

Prolonged shock or hypotension can lead to

acute kidney injury, characterized by elevated serum creatinine and

decreased urine output (Fischer et al., 2018).

Severe hypotension or hypoxia can affect brain

function, leading to confusion, dizziness, or

even loss of consciousness (Fischer

et al., 2018).

Severe anaphylaxis with associated hypoxia or

metabolic disturbances can increase the risk of seizures (Fischer et al.,

2018).

In cases where resuscitation is needed,

there is a risk of rib fractures or other injuries from chest

compressions (Fischer et al., 2018).

Some individuals may experience a biphasic

reaction, where symptoms return after

initial improvement, typically 4-8 hours after the initial episode. This can result in prolonged

or additional complications (Fischer

et al., 2018).

Some individuals may develop chronic

conditions such as reactive airway disease

or persistent gastrointestinal

symptoms following severe anaphylaxis

(Fischer et al., 2018).

Experiencing a severe anaphylactic reaction

can lead to anxiety, fear, or PTSD, affecting the individual’s quality

of life (Fischer et al., 2018).

Delaying epinephrine administration or

inadequate dosing can worsen the severity of

the reaction and increase the risk of

severe complications or mortality (Fischer et al.,

2018).