Chapter 25 Immunologic Emergencies. National EMS Education Standard Competencies Medicine Integrates assessment findings with principles of epidemiology

Chapter 25Chapter 25

Immunologic Emergencies

National EMS Education Standard CompetenciesNational EMS Education Standard Competencies

Medicine

Integrates assessment findings with principles of epidemiology and pathophysiology to formulate a field impression and implement a comprehensive treatment/disposition plan for a patient with a medical complaint.


Immunology

•Recognition and management of shock and difficulty breathing related to

− Anaphylactic reactions


Immunology

•Anatomy, physiology, pathophysiology, assessment, and management of hypersensitivity disorders and/or emergencies

− Allergic and anaphylactic reactions


Immunology

•Anatomy, physiology, epidemiology, pathophysiology, psychosocial impact, presentations, prognosis, and management of common or major immunologic system disorders and/or emergencies

− Hypersensitivity

− Allergic and anaphylactic reactions


Immunology

•Anatomy, physiology, epidemiology, pathophysiology, psychosocial impact, presentations, prognosis, and management of common or major immunologic system disorders and/or emergencies (cont’d)

− Anaphylactoid reactions

− Collagen vascular diseases

− Transplant-related problems

IntroductionIntroduction

• 1,500 Americans die of acute allergic reactions every year.− Be prepared to treat acute airway obstruction

and cardiovascular collapse.

− Be able to distinguish between a regular response and an allergic reaction.


• Immune response problems include:− Anaphylaxis

− Anaphylactoid reactions

− Allergic reactions

− Hypersensitivity

− Collagen vascular diseases

− Transplant-related disorders


• Allergen: Substance that produces allergic symptoms

• Antibody: Protein produced in response to an antigen


• Allergic reaction: An abnormal immune response− Local reaction: limited to a specific area

− Systemic reaction: occurs throughout the body

• Hypersensitivity: Inappropriate allergic symptoms from a substance


• Anaphylaxis: Systemic allergic reaction− No exact cause in up to two thirds of patients

− Allergy-related diseases increase the risk.

− Other major factors include:• The route of exposure

• The time between exposures



• Anaphylactoid reaction does not involve IgE antibody mediation.− May occur without previous exposure

− Patient presentation is the same.


• Collagen vascular diseases − Autoimmune disorders

− The body perceives its own collagen tissue as a danger and attacks that tissue.


• Collagen vascular diseases (cont’d)− Systemic lupus erythematosus (SLE or lupus)

• Multisystem autoimmune disease

• Often diagnosed in women of childbearing age

• Can attack multiple systems

• Survival rate is currently at 15 years


• Collagen vascular diseases (cont’d)− Scleroderma

• Autoimmune connective tissue disease

• Can be either localized or systemic

• Patients are at greatest risk of dying from organ damage during the first three years.


• Patients with organ transplants receive immune system suppression medications.− Be prepared to identify rejection, infection, and

medication toxicity signs.


• Infection is the greatest threat in an organ transplant.− Taking immuno-

suppressant medications is essential.

− Drug toxicity is also a danger.

The Normal Immune ResponseThe Normal Immune Response

• Immune system protects body− Cellular immunity: T cells attack and destroy

antigens.

− Humoral immunity: B cell lymphocytes produce antibodies to attack foreign organisms.

Routes of Entry for AllergensRoutes of Entry for Allergens

• Skin: injection or absorption

• Inhalation: patient breathes in allergens

• Ingestion: through the gastrointestinal tract

PhysiologyPhysiology

• Primary response: Macrophages confront and engulf antigens.− Substances that cannot be identified are

recorded.• Antibodies are intended to match the antigen and

inactivate it.


• The body develops sensitivity.− The body distributes details to the rest of the

body by placing the antibodies on:• Basophils

• Mast cells


• Basophils and mast cells produce chemical mediators to fight antigens.− Summon white

blood cells

− Increase blood flow


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• Vaccine administration sends a small amount of virus into the body.− Body produce antibodies to it

− If an immunized person is later exposed, the immune cells identify and kill the virus.• Secondary response


• Acquired immunity: Vaccine allows the body to produce antibodies without becoming ill.

• Natural immunity: The body experiences the full immune response.

• Herd immunity: When a group is immunized

Scene Size-UpScene Size-Up

• Assess the scene for safety issues.

• Determine the nature of the illness.− Check for potential exposure venues.

Primary AssessmentPrimary Assessment

• Evaluate:− Level of consciousness

− Respiratory system

− Circulatory system

− Mental status

− Skin


• Allergic reactions can be local or systemic.

• Categories:− Mild: affecting a local area

− Moderate: mild signs spread through the body

− Severe: anaphylactic reactions


• Form a general impression.− Observe for indication of severity.

− If the patient cannot speak, assess the airway.

− Level of conscious indicates: • Severity of the reaction

• Oxygen and circulatory status


• Breathing and airway− A noisy upper airway may be a sign of

impending airway occlusion.• Check for stridor and hoarseness.

• The patient may report tightness in the throat.


• Breathing and airway (cont’d)− Lung sounds are a predictor of severity.

− As hypoventilation begins, there will be:• Diminished lung sounds

• Silence (ominous finding)


• Circulation− Evaluate skin for histamine release symptoms,

which may include:• Erythema

• Edema

• Pruritus

• Urticaria


• Transport decision− May include:

• Remaining on the scene

• Initiating treatment in the vehicle

• Beginning immediate transport

• Calling for air transport

− Determine which facility to transport to.

History TakingHistory Taking

• Should be directed at the current complaint− Does the patient have allergies?

− Have they ever had an allergic reaction?

• Ask about medications.

History TakingHistory Taking

• Intervention takes precedence over identifying antigen.− Determine if

treatment was administered:• EpiPen

• Benadryl

• Beta-agonist inhaler

• Aerosolized epinephrine

© Kumar Sriskandan/Alamy Images

Secondary AssessmentSecondary Assessment

• Physical examinations− Evaluate the respiratory system.

• Assess breathing.

• Auscultate the trachea and chest.

• Wheezing may be present.

• Prolonged respiratory difficulty may lead to death.


• Physical examinations (cont’d)− Assess the circulatory system.

• Hypoperfusion or respiratory distress indicates severe allergic reaction.

− A systemic reaction may present as:• Rash; red, hot skin; altered mental status


• Vital signs− Assess baseline vital signs.

− Airway obstruction: rapid, labored breathing

− Respiratory distress or shock: rapid respiratory and pulse rates


• Monitoring devices− Cardiac monitor for dysrhythmias

− 12-lead ECG for cardiac ischemia

− ETCO2 for bronchoconstriction

− Pulse oximetry for oxygen saturation levels

ReassessmentReassessment

• Should be done en route − Focus on signs of airway compromise.

− Monitor the patient’s anxiety and the skin.

− Conduct serial vital signs.

− Reassess the chief complaint.


• Interventions− Identify the amount of distress.

• Severe reactions require epinephrine and ventilatory support.

• Milder reactions require supportive care.


• Interventions (cont’d)− Recheck the interventions.

• A second dose of epinephrine may be needed.

− Identify and treat any changes in condition.

− In anaphylaxis cases, check interventions.


• Interventions (cont’d)− Call in the patient report and include:

• The patient’s status

• Interventions completed

• The patient’s responses

• Estimated time of arrival

Anaphylactic ReactionsAnaphylactic Reactions

• Pathophysiology− Immune system

becomes hypersensitive.• Identify harmless

substances as a threat.

Courtesy of Carol B. Guerrero


• Pathophysiology (cont’d)− When an invading substance enters the body,

mast cells release chemical mediators.• In anaphylaxis, the effect involves more than one

body system.


• Pathophysiology (cont’d)− Histamine causes:

• Vasodilation

• Vascular permeability

• Smooth muscle contraction

• Decreased effects of the heart

© Chuck Stewart, MD


• Pathophysiology (cont’d)− Leukotrienes cause:

• Respiratory system becomes more dire

• Coronary vasoconstriction

• Increased vascular permeability


• Clinical symptoms of anaphylaxis− Patient

experiences three types of shock:• Cardiogenic shock

• Hypovolemic shock

• Neurogenic shock


• Assessment− It may be necessary to simultaneously:

• Assess the patient.

• Identify the problem.

• Intervene.


• Management− Patients with allergic reaction signs but no

respiratory distress:• Diphenhydramine (Benadryl)

• Monitor for changes.


• Management (cont’d)− If signs of allergic

reaction and dyspnea:• Deliver oxygen,

epinephrine, and antihistamines.

• Monitor for anaphylaxis.

− Remove offending agent.


• Management (cont’d)− Maintain airway and prepare to intubate.

• Cricothyrotomy may be necessary.

• Assess for stridor and hoarseness.

• Administer supplemental oxygen.

• Early administration of epinephrine should be a priority.


• Management (cont’d)− Administer epinephrine.

• Immediately stops the process

• Reverses the effects of the chemical mediators

• An EpiPen may have already been used.


• Management (cont’d)− Maintain circulation.

• Administer 1 to 2 L of an isotonic solution.

• If there is no response up to 4 L may be needed.

• If there is still no response, consider a vasopressor.


• Management (cont’d)− Initiate pharmacologic therapy.

− Be prepared to assist ventilation.

− Monitor for adverse effects to epinephrine.

− Reassess vital signs at least every 5 minutes.


• Management (cont’d)− If not accompanied

by hypotension or airway compromise, treat with epinephrine.• Adults: 0.3 to 0.5

mg

• Children: 0.001 mg/kg


• Management (cont’d)− Antihistamine administration should only be

considered after epinephrine.

− Corticosteroids may prevent late reactions.

− Consider glucagon if no response to epinephrine.


• Management (cont’d)− Consider vasopressors if no response to fluids.

− If bronchospasm is present, consider inhaled beta-adrenergic agents.

− Psychological support is crucial.

Collagen Vascular DiseasesCollagen Vascular Diseases

• Pathophysiology− Systemic lupus erythematosus (SLE or lupus)

• Multisystem autoimmune disease

• Monitor for life threats.

• Patients may be on immunosuppressive medications.


• Pathophysiology (cont’d)− Scleroderma

• Presents with tightening, thickening, and scarring

• Often include symptoms of Raynaud phenomenon

• Damage to the heart muscle is a major complication.


• Assessment− Rule out life threats.

• Management− Treat any life threats.

− Monitor for signs of infection.

Organ Transplant DisordersOrgan Transplant Disorders

• Pathophysiology− Immune system tries to reject the organ.

− Patients are given antirejection medications.

− Address priorities in caring for specific transplanted organs.


• Heart transplant− The recipient’s heart is usually removed, but

may be left in place.

− Atropine is not indicated.

− Sympathomimetic drugs work well.


• Heart transplant (cont’d)− Signs and symptoms of infection may include:

• Shortness of breath

• Hypotension pressure

• Poorly controlled hypertension

• A new dysrhythmia


• Liver transplant− The loss of function causes rapid deterioration.

− Watch for infection.

• Kidney transplant− Infection is a major concern.

− Recipients tend to develop hepatitis C and later liver disease.


• Lung transplant− Usually performed unilaterally

− Signs of rejection may include:• Cough

• Dyspnea

• Rales

• Decrease in oxygenation


• Pancreas transplant− More complications and a lower survival rate at

1 year than other transplants

− Exocrine component is usually drained into the bladder, along with the bicarbonate

− Infection and rejection are common problems.


• Assessment− Be aware of subtle signs and symptoms.

− Signs and symptoms vary.

− Consider calling the transplant center for any questions.


• Management− Priorities:

• Organ transplanted

• Medications

• Recognition of infection or rejection


• Management (cont’d)− Understand how medications will interact and

how they will be metabolized.

− Monitor for infection or organ rejection.

− Consider transport to the transplant facility when possible.

Patient EducationPatient Education

• Anaphylaxis− Avoid the antigen.

− Notify all health personnel.

− Wear identification tags or bracelets.

− Carry an anaphylaxis kit.

− Report symptoms early.

Patient EducationPatient Education

• Collagen vascular diseases and organ transplants− Encourage self-monitoring.

− Consult a physician before taking a new medication.

− Comply with the immunosuppressive regimen.

− Know who to contact.

SummarySummary

• An antigen is a substance the body recognizes as foreign.

• The immune system is responsible for the antigen–antibody response.

• An allergic response occurs when the body produces the antigen–antibody response when exposed to a normally harmless substance.

SummarySummary

• Anaphylaxis is an extreme form of systemic allergic response involving two or more body systems.

• A person must be sensitized to an antigen before an allergic or anaphylactic response occurs.

• An anaphylactoid reaction may occur with no previous exposure of the allergen.

SummarySummary

• Exposure can come from injection, absorption, inhalation, and ingestion.

• Mast cells release chemical mediators to stimulate the allergic reaction.

• Chemical mediators produce signs and symptoms on the skin, cardiovascular, respiratory, neurologic, and gastrointestinal systems.

SummarySummary

• Skin effects include erythema, urticaria, and pruritus.

• Cardiovascular effects include vasodilation, hypotension, decreased cardiac output, cardiac ischemia, and dysrhythmias.

• Respiratory effects include upper airway edema and stridor, hoarseness, bronchoconstriction, increased bronchial secretions, wheezes, and hypoxia.

SummarySummary

• Neurologic systems include altered level of consciousness, anxiety, restlessness, combativeness, and unconsciousness.

• Gastrointestinal symptoms include nausea, vomiting, diarrhea, and cramping.

• The assessment should include evaluating the scene, patient history, level of consciousness, upper airway, lower airway, skin, and vital signs.

SummarySummary

• To treat anaphylaxis:− Remove the offending agent.

− Maintain airway.

− Administer medications.

− Resuscitate with IV fluids.

− Initiate rapid transport.

SummarySummary

• Epinephrine is the first-line drug therapy.

• Patient education is essential.

• Collagen vascular and other autoimmune diseases may require medications to suppress the immune system.

• It is important to know the treatment priorities for patients with organ transplant disorders.

CreditsCredits

• Chapter opener: © Jones & Bartlett Learning. Courtesy of MIEMSS.

• Backgrounds: Gold—Jones & Bartlett Learning. Courtesy of MIEMSS; Purple—Jones & Bartlett Learning. Courtesy of MIEMSS; Green—Courtesy of Rhonda Beck; Red—© Margo Harrison/ShutterStock, Inc.

• Unless otherwise indicated, all photographs and illustrations are under copyright of Jones & Bartlett Learning, courtesy of Maryland Institute for Emergency Medical Services Systems, or have been provided by the American Academy of Orthopaedic Surgeons.

Documents

Chapter 25 Immunologic Emergencies. National EMS Education Standard Competencies Medicine Integrates assessment findings with principles of epidemiology