anaphalactic shock

Anaphylactic Shock
Anaphylactic shock occurs rapidly and is life-threatening.
• Anaphylactic shock is a systemic, type I hypersensitivity
reaction that often has fatal consequences.
• Anaphylaxis causes the immune system to release a
flood of chemicals that can cause a person to go into shock.

Anaphylaxis occurs in an individual after reexposure to an antigen to which that person has produced a specific IgE
antibody.

• Reexposure. Upon reexposure to the sensitized allergen, the allergen may cross-link the mast cell or basophil
surface-bound allergen-specific IgE resulting in cellular degranulation as well as de novo synthesis of mediators.

• Binding. Immunoglobulin E (IgE) binds to the antigen (the foreign material that provokes the allergic reaction).
• Activation. Antigen-bound IgE then activates FcεRI receptors on mast cells and basophils.

• Inflammatory mediators release. This leads to the release of inflammatory mediators such as histamine.

• Histamine release. Many of the signs and symptoms of anaphylaxis are attributable to binding of histamine to its
receptors; binding to H1 receptors mediates pruritus, rhinorrhea, tachycardia, and bronchospasm.

• Prostaglandin D2. Prostaglandin D2 mediates bronchospasm and vascular dilatation, principal manifestations of
anaphylaxis.

• Leukotriene C4. Leukotriene C4 is converted into LTD4 and LTE4, mediators of hypotension, bronchospasm, and
mucous secretion during anaphylaxis in addition to acting as chemotactic signals for eosinophils and neutrophils.

Schematic representation of the pathophysiology of anaphylaxis and the specific role of the released mediators
on heart and vessels. IgE, immunoglobulin E.

Anaphylaxis occurs worldwide and in different ages.

• Worldwide, 0.05–2% of the population is estimated to experience anaphylaxis at
some point in life.

• It occurs most often in young people and females.

• Of people who go to a hospital with anaphylaxis in the United States
about 0.3% die.

• According to a peer-reviewed study, anaphylaxis very likely occurs in nearly 1 in
50 Americans (1.6%).

• Researchers also found that 13% of cases of anaphylaxis occur at hospitals or
clinics, 6.4% at a relative’s or a friend’s home, 6.1% in the workplace, 6.1% in the
restaurant, and 2.6% at school.

Allergy symptoms aren’t usually life-threatening, but a severe allergic reaction can
lead to anaphylaxis.

• Food allergies. The most common anaphylaxis triggers in children are food
allergies, such as to peanuts, and tree nuts, fish, shellfish and milk.

• Medication allergies. Certain medications,
• including antibiotics, aspirin and other over-the-counter pain relievers, and the

intravenous (IV) contrast used in some imaging tests.
• Insect allergies. Stings from bees, yellow jackets, wasps, hornets and fire ants.
• Latex allergy. Latex allergy develops after many previous exposures to latex.

An anaphylactic reaction produces the following symptoms:

• Anxiety. The first symptoms usually include a feeling of impending doom or
fright.

• Skin reactions. Skin reactions such as hives, itching, and flushed or pale skin
follow.

• Shortness of breath. Constriction of the airways and a swollen tongue or throat
could cause wheezing and troubled breathing.

• Hypotension. A low blood pressure occurs as one of the major symptoms of
shock.

• Tachycardia. The heart compensates through pumping faster and trying to
deliver blood to all body systems.

• Dizziness. The patient may feel dizzy which could lead to fainting.

Because anaphylactic shock occurs in patients already exposed to an antigen and
who have developed antibodies to it, it can often be prevented.

• Avoid exposure to allergens. Teach the patient to avoid exposure to known
allergens, may it be food, drug, or an insect bite.

• Desensitization. If a patient must receive a drug to which he’s allergic, prevent
a severe reaction by making sure he receives careful desensitization with
gradually increasing doses of the antigen or advance administration of steroids.

• Monitoring. Closely monitor a patient undergoing diagnostic tests that
use radiographic contrast media, such as excretory urography, cardiac
catheterization, and angiography.

The complications of anaphylactic shock include:

• Respiratory obstruction. The trachea may close up
due to severe inflammation which could result to
respiratory obstruction.

• Systemic vascular collapse. Sudden loss of blood
flow to the brain and other organs could cause
systemic vascular collapse.

Because anaphylaxis is primarily a clinical diagnosis, laboratory studies are not usually required and are rarely
helpful.

• Histamine and tryptase assessment. If a patient is seen shortly after an episode, plasma histamine or urinary
histamine metabolites, or serum tryptase measurements may be helpful in confirming the diagnosis.

• 5-hydroxyindoleacetic acid levels. If carcinoid syndrome is considered, urinary 24-hour 5-hydroxyindoleacetic
acid levels should be measured.

• Testing for food allergy. If the patient’s medical history and physical examination findings suggest a possible
association with food ingestion, percutaneous (puncture) food allergen–specific skin tests and/or in vitro–
specific IgE tests (eg, radioallergosorbent assay test [RAST] or ImmunoCAP IgE tests [Phadia AB; Uppsala,
Sweden]) can be performed, with an understanding that both false-positive and false-negative results may
occur.

• Testing for medication allergy. If the patient’s history suggests a penicillin etiology and the reagents are
available, skin testing for penicillin should be performed with the appropriate positive and negative controls.

• Testing for suspected insect bites or sting. If the patient’s history suggests an insect sting, allergen-specific
skin testing to Hymenoptera venoms should be performed.

Treatment of anaphylactic shock include:

• Remove antigen. Removing the causative antigen such as discontinuing an
antibiotic agent could stop the progression of shock.

• Administer medications. Administer medications that restore vascular tone
and provide emergency support of basic life functions.

• Cardiopulmonary resuscitation. If cardiac arrest and respiratory arrest are
imminent or have occurred, cardiopulmonary resuscitation is performed.

• Endotracheal intubation. Endotracheal intubation or tracheostomy may be
necessary to establish an airway.

• Intravenous therapy. IV lines are inserted to provide access for administering
fluids and medications.

Medications used for a patient at risk or under anaphylactic shock are:

• Epinephrine. Epinephrine is given for its vasoconstrictive reaction;
for emergency situations, an immediate injection of 1:1, 000
aqueous solution, 0.1 to 0.5 ml, repeated every 5 to 20 minutes is
given.

• Diphenhydramine. Diphenhydramine (Benadryl) is administered to
reverse the effects of histamine, thereby reducing capillary
permeability.

• Albuterol. Albuterol (Proventil) may be given to reverse histamine-
induced bronchospasm.

Nursing Management
The nurse has an important role in preventing anaphylactic shock.

Nursing Assessment
Communication is an essential part of assessment.

• Assess any kind of allergy. The nurse must assess all patients for allergies or
previous reactions to antigens.

• Assess patient’s knowledge. The nurse must also assess the patient’s
understanding of previous reactions and steps taken by the patient and the
family to prevent further exposure to antigens.

• New allergies. When new allergies are identified, the nurse advises the patient
to wear or carry identification that names the specific allergen or antigen.

Nursing Diagnosis
Based on the assessment data, the nursing diagnoses appropriate for
the patient are:

1. Impaired gas exchange related to ventilation perfusion imbalance.
2. Altered tissue perfusion related to decreased blood

flow secondary to vascular disorders due to anaphylactic reactions.
3. Ineffective breathing pattern related to the swelling of the nasal

mucosa wall.
4. Acute pain related to gastric irritation.
5. Impaired skin integrity related to changes in circulation.

The major goals for a patient with anaphylactic shock are:

1. Client will maintain an effective breathing pattern, as evidenced by relaxed breathing at normal rate and
depth and absence of adventitious breath sounds.

2. Client will demonstrate improved ventilation as evidenced by an absence of shortness of breath and
respiratory distress.

3. Client will display hemodynamic stability, as evidenced by strong peripheral pulses; HR 60 to 100
beats/min with regular rhythm; systolic BP within 20 mm Hg of baseline; urine output greater than 30 ml/hr;
warm, dry skin; and alert, responsive mentation.

4. Client and significant others will verbalize understanding of allergic reaction, its prevention, and
management.

5. Client and significant others will verbalize understanding of need to carry emergency components for
intervention, need to inform health care providers of allergies, need to wear medical alert
bracelet/necklace, and the importance of seeking emergency care.

Nursing interventions for the patient are:

• Monitor client’s airway. Assess the client for the sensation of a narrowed airway.

• Monitor the oxygenation status. Monitor oxygen saturation and arterial blood gas values.

• Focus breathing. Instruct the client to breathe slowly and deeply.

• Positioning. Position the client upright as this position provides oxygenation by promoting
maximum chest expansion and is the position of choice during respiratory distress.

• Activity. Encourage adequate rest and limit activities to within client’s tolerance.
• Hemodynamic parameters. Monitor the client’s central venous pressure (CVP), pulmonary

artery diastolic pressure (PADP), pulmonary capillary wedge pressure, and cardiac output/cardiac
index.

• Monitor urine output. The renal system compensates for low blood pressure by retaining water,
and oliguria is a classic sign of inadequate renal perfusion.

Expected patient outcomes include:

• Client maintained an effective breathing pattern.
• Client demonstrated improved ventilation.
• Client displayed hemodynamic stability.
• Client and significant others verbalized understanding of allergic reaction, its

prevention, and management.
• Client and significant others verbalized understanding of need to carry

emergency components for intervention, need to inform health care providers of
allergies, need to wear medical alert bracelet/necklace, and the importance of
seeking emergency care.

Upon discharge, the patient and family need to learn about
the following:

• Emergency medications. The nurse should provide
information about emergency medications and plans that
should be considered should a crisis reoccur.

• Precipitating factors. The nurse must assist the client
and/or family in identifying factors that precipitate and/or
exacerbate crises.

The focus of documentation include:

• Assessment findings including respiratory rate, character of breath sounds; frequency, amount, and
appearance of secretions; presence of cyanosis; laboratory findings; and mentation level.

• Conditions that may interfere with oxygen supply.
• Pulses and BP, including above and below affected area.
• Client’s description of response to pain, specifics of pain inventory, expectations of pain management, and

acceptable level of pain.
• Prior medication use.
• Plan of care, specific intervention, and who is involved in planning.
• Teaching plan.
• Client’s responses to treatment, teaching, and actions performed.
• Attainment or progress towards desired outcome.
• Modifications to plan of care.
• Long-term needs.



❑Anaphylactic Shock also known as distributive shock, or vasogenic shock is
a life-threatening allergic reaction that is caused by a systemic antigen-antibody
immune response to a foreign substance (antigen) introduced into the body.

❑It is characterized by a smooth muscle contraction, massive vasodilation and
increased capillary permeability triggered by a release of histamine.

❑It occurs within seconds to minutes after contact with an antigenic substance and
progresses rapidly to respiratory distress, vascular collapse, systemic shock, and
possibly death if emergency treatment is not initiated.

❑Causative agents include severe reactions to a sensitive substance such as a
drug, vaccine, food (e.g., eggs, milk, peanuts, shellfish), insect venom, dyes or
contrast media, or blood products.

Nursing Care Plans
Anaphylactic shock is a medical emergency that requires immediate attention
and intervention. Nursing care management is dependent on the severity of the
initial reaction and the treatment response.

Here are four (4) nursing care plans (NCP) and nursing diagnosis for
patients with anaphylactic shock:

1. Ineffective Breathing Pattern
2. Impaired Gas Exchange
3. Decreased Cardiac Output
4. Deficient Knowledge

May be related to Possibly evidenced by
• Bronchospasm. • Chest tightness.
• Bronchoconstriction. • Cyanosis.
• Facial angioedema. • Coughing.
• Laryngeal edema. • Dyspnea.
• Hoarseness.
• Respiratory distress.
• Stridor.
• Tachypnea.
• Use of accessory muscles.
• Wheezing.

Desired Outcomes
• Client will maintain an effective breathing pattern, as evidenced

by relaxed breathing at normal rate and depth and absence of
adventitious breath sounds.

Nursing Interventions Rationale
Assess the respiratory rate, rhythm, and
depth, and note for changes such as: Histamine is the primary mediator of anaphylactic shock. It causes
smooth muscle contraction in the bronchi as a result of the
• Coughing. stimulation of histamine receptors (H1). As the anaphylactic
• Dyspnea. reaction progresses, the client develops dyspnea, wheezing, and
• Increased shortness of breath. increased pulmonary secretions. Vascular to interstitial fluid shifts
• Stridor. to contribute to respiratory distress through swelling in the upper
• Tachypnea. airways.
• Use of accessory muscles.
• Wheezing. By auscultation, wheezing can be heard over the entire chest. But
when the bronchial constriction worsens, there will be decreased
Auscultate breath sounds. audible wheezing and respiratory distress will heighten. Therefore,
it is also important to auscultate for decreasing air movement.

Nursing Interventions Rationale

Assess the client’s anxiety level. Life-threatening situations such as respiratory distress and
shock can produce elevated levels of anxiety within the client.

Systemic antigen-antibody immune response can result in

Assess the client for the sensation of a severe bronchial airway narrowing, edema, and obstruction. As

narrowed airway. airway gets narrow, client demonstrates increase respiratory

effort.

Observe for changes in color of the skin, tongue, Bluish discoloration of these body parts is considered a medical

and mucosa. emergency.

Assess the presence of angioedema. Angioedema is characterized by the swelling of the skin, lips,
tongue, hands, eyelids, and feet.

Pulse oximetry is used to monitor oxygen saturation. It should

Monitor oxygen saturation and arterial blood be kept at least 90% or higher. As shock progresses, aerobic

gasses. metabolism stops and lactic acidosis occurs, resulting in the

increased level of carbon dioxide and decreasing pH.

Nursing Interventions Rationale

Maintain a calm, assured manner. Assure the The staff’s anxiety may be easily perceived by the client. The

client and significant others of close, client’s feeling of stability increases in a calm, non-threatening

continuous monitoring that will ensure prompt environment. The presence of a trusted person can help the

intervention. client feel less threatened.

Provide assurance and alleviate anxiety by Air hunger can produce an extremely anxious state that leads

staying with the client during acute distress. to rapid and shallow respirations.

Instruct the client to breathe slowly and deeply. Focus breathing may help calm the client, and the increase
tidal volume facilitates improved gas exchange.

This position provides oxygenation by promoting maximum

Position the client upright. chest expansion and is the position of choice during

respiratory distress.

Administer IV fluids as ordered. Hypotension caused by vasodilation and distributive shock
responds to fluid resuscitation.

Oxygen increase arterial saturation. Oxygen saturation that is

Administer oxygen as prescribed. less than 90% results to tissue hypoxia, acidosis, dysrhythmias,

and changes in the level of consciousness.

Nursing Interventions Rationale

Administer medications as ordered:

These medications reduce bronchospasm and help open the

• Bronchodilators. airways in the lungs by relaxing smooth muscle around the
airways.

• Corticosteroids. Steroids stabilize the cell membrane and decrease cellular
permeability, vasomotor response, and inflammation.

Epinephrine is the cornerstone of anaphylaxis management. It is

• Epinephrine. fast-acting and relaxes pulmonary vessels to improve air exchange
and stabilizes cellular permeability.

• H1-receptor blockers/antihistamines. These medications block the action of histamine and decrease
cellular edema.

Maintain a patent airway. Anticipate an emergency intubation Respiratory distress may progress rapidly. If laryngeal edema is
or tracheostomy if stridor occurs. present, endotracheal intubation will be required to maintain a
patent airway.

Home care:

• Provide information about emergency medications and Adequate preparation decreases risks.
plans that should be considered should a crisis reoccur.

• Assist the client and/or family in identifying factors that Knowledge can facilitate prompt intervention.
precipitate and/or exacerbate crises.

May be related to
• Ventilation-perfusion imbalance.

Possibly evidenced by
• Bronchospasm.
• Dyspnea.
• Hypotension.
• Shock.
• Shortness of breath.
• Tachycardia.

Desired Outcomes
• Client will demonstrate improved ventilation as evidenced by an absence of

shortness of breath and respiratory distress.

Nursing Interventions Rationale
Note respiratory rate, frequency, depth and ease breathing.
Increased respiratory effort may show the extent of the level of hypoxemia and
Auscultate breath sounds. useful in evaluating the degree of compromise.

Assess the level of consciousness/mental changes. By auscultation, wheezing can be heard over the entire chest. But when the
bronchial constriction worsens, there will be decreased audible wheezing and
Monitor oxygen saturation and arterial blood gasses. respiratory distress will heighten. Therefore, it is also important to auscultate for
decreasing air movement.
Maintain the patency of the airway.
Anxiety or restlessness, confusion, and headaches are other common effects of
Elevate head of bed; Provide airway adjuncts and suction as mild hypoxemia.
indicated.
Pulse oximetry is used to monitor oxygen saturation. It should be kept at least 90%
Provide oxygen therapy correctly as indicated. or higher. As shock increases, aerobic metabolism stops and lactic acidosis
Encourage adequate rest and limit activities to within client’s happens, resulting in the increased level of carbon dioxide and decreasing pH.
tolerance.
Administer medications as ordered (corticosteroids, Airway obstruction may alter ventilation and impairs gas exchange.

This position promotes adequate oxygenation; Airway adjuncts such as
oropharyngeal airway (OPA) and nasopharyngeal airway (NPA) are designed to
maintain airway patency, allowing spontaneous respiration or facilitating bag-
mask ventilation.

Oxygen therapy will maintain PaO2 above 60 mm Hg.

This will promote calm and restful environment and will limit the client’s oxygen
needs.

Used to prevent allergic reactions / inhibit histamine release, reduces airway

May be related to
• Generalized vasodilation (decreased preload and afterload).
• Increased capillary permeability (fluid shifts).

Possibly evidenced by
• Cyanosis; pallor.
• Decreased central venous pressure (CVP).
• Decreased peripheral pulses.
• Decreased pulmonary pressures.
• Dizziness.
• Hypotension.
• Oliguria.
• Prolonged capillary refill.
• Restlessness.
• Tachycardia.

Desired Outcomes
• Client will display hemodynamic stability, as evidenced by strong peripheral pulses; HR 60 to 100 beats/min with regular

rhythm; systolic BP withing 20 mm Hg of baseline; urine output greater than 30 ml/hr; warm, dry skin; and alert, responsive
mentation.

Nursing Interventions Rationale

Severe hypovolemia and hypotension result from the intense

Assess the client’s HR and BP, including peripheral pulses. vasodilation; Pulses are weak with decreased stroke volume

and cardiac output.

Assess the client’s ECG for dysrhythmias. Cardiac dysrhythmias may occur from the low perfusion state,
acidosis, or hypoxia.

Assess the client’s level of consciousness. Early signs of cerebral hypoxia are restlessness and anxiety
while confusion and loss of memory occurs in late stage.

Massive vasodilation and increased capillary permeability can

Assess the skin temperature and signs of any cyanosis. lead to decreased peripheral blood flow and ineffective tissue

perfusion.

The renal system compensates for low blood pressure by

Monitor the client’s urine output. retaining Water. Oliguria is a classic sign of inadequate renal

perfusion.

Hemodynamic parameters provide information aiding in the

Monitor the client’s central venous pressure (CVP), differentiation of decreased cardiac output secondary to the

pulmonary artery diastolic pressure (PADP), pulmonary fluid deficit (fluid shifts) or fluid overload (aggressive IV

capillary wedge pressure, and cardiac output/cardiac therapy). CVP is used as an estimate of right ventricular

index. preload; pulmonary capillary wedge pressure and pulmonary

artery diastolic pressure indicate left-sided fluid volumes.

Nursing Interventions Rationale

Place the client with the head of the bed flat, with the
trunk horizontal and the lower extremities elevated 20 to This position promotes optimal venous return.
30 degrees with the knees straight.

Administer volume expanders as ordered. Volume expanders are used to correct hypovolemia.

Administer parenteral fluids using a large-bore needle. Volume therapy is essential to maintain sufficient filling pressures and adequate
Avoid fluid overload in older clients. cardiac output.

If a blood transfusion is causing the reaction, immediately

terminate the infusion and keep the vein open using These safety measures must be done to eliminate further complications.

a normal saline solution then notify the physician.

Administer medications as ordered.

• Corticosteroids. Steroids may be used to suppress immune and inflammatory responses and
reduce capillary permeability.

Epinephrine is an endogenous catecholamine with both alpha- and beta- receptor

• Epinephrine. stimulating actions that provide rapid relief of hypersensitivity reactions. It is
unknown whether epinephrine prevents mediator release or whether it reverses
the action of mediators on the target tissues., but its early administration is

critical. For prolonged reactions, it may be necessary to repeat the dose.

• Glucagon. Glucagon reverses hypotension in clients taking beta blocker medications who are
unresponsive to fluid administration and epinephrine.

• H1-receptor blockers and/or antihistamine Antihistamine blocks the action of histamine and reverses their adverse effects.
(diphenhydramine).

May be related to
• Lack of exposure.

• Lack of recall.

• Misinterpretation of information.

Possibly evidenced by
• Inaccurate follow-through of instructions.

• Inability to identify allergens.

• Recurrent allergic reactions.

Desired Outcomes
• Client and significant others will verbalize understanding of allergic reaction, its prevention, and

management.

• Client and significant others will verbalize understanding of need to carry emergency components for
intervention, need to inform health care providers of allergies, need to wear medical alert
bracelet/necklace, and the importance of seeking emergency care.

Nursing Interventions Rationale
Assess the client’s knowledge of the condition and exposure to
allergens. Present knowledge of the client provides a baseline for
immediate treatment.
Explain factors that may increase the risk of anaphylaxis (e.g.,
certain drugs, blood products, insect venom, food and Information allows the client to take control and make
environmental control measures to be established). needed lifestyle modifications. For example, if the trigger is
pollen, the client will need to shower, change and wash
Instruct the client with known allergies to wear medical alert clothes after they’ve spent time outdoors.
identification.
In case of emergency, health care provider will be aware of
Instruct the client or family members about factors that can this medical history.
precipitate a recurrence of shock and ways to prevent or avoid
these precipitating factors. The client is at high risk for developing anaphylactic shock
in the future if exposed to the same antigenic substance
Instruct the client in the use of insect sting kits (containing a and needs self-help information to prevent anaphylactic
chewable antihistamine), epinephrine in prefilled syringes, and shock.
instructions for use as appropriate, and indicate how they are to
be obtained. In a situation in which the client cannot completely avoid
exposure to allergens, he or she needs to have access to
emergency treatment resources for immediate
administration. These can be self-administered or given by
someone else.

Nursing Interventions Rationale

Notify the client or significant others to divulge in the medical history Safety measures reduce potential injury. Health care
all their allergies (e.g., blood products, food, pollen, latex, medications, providers need to be aware of both history of the
contrast dyes, dust mites). reaction, causative factors, symptoms, and severity,
and the level of the treatment period.

Provide instruction in self-care measures to be performed at home
during the initial attack:

• During an episode of a drop in blood pressure (dizziness), lie down
with the feet elevated.

• During an episode of wheezing, use a prescribed inhaled During initial attacks, the client should be prepared to
bronchodilator.
stay calm and follow safety instructions; The EpiPen is
• During an episode of a severe reaction, inject self with epinephrine injected into the thigh muscle.
from the kit (EpiPen).

• Minimize exposure to the trigger if possible.

• Take an oral antihistamine (Benadryl) if swallowing is intact.

• Call 911 for help, or have someone drive to the hospital before the
attack increases.

Discuss referral to an allergist if allergens are difficult to avoid. Skin tests are being used to identify the
specific allergen. Clients may also benefit from
desensitization.