Learning Objectives
By the end of this section, you will be able to:
- Discuss the pathophysiology, risk factors, and clinical manifestations for anaphylaxis
- Describe the diagnostics and laboratory values in the disease of anaphylaxis
- Apply nursing concepts and plan associated nursing care for patients with anaphylaxis
- Evaluate the efficacy of nursing care for patients with anaphylaxis
- Describe the medical therapies that apply to the care of anaphylaxis
Anaphylaxis generally occurs within minutes to hours of exposure and involves the integumentary, respiratory, cardiovascular, and gastrointestinal systems. The Allergy and Asthma Network (2023) reported that 1.5 to 5.1 percent of the American population has undergone anaphylaxis. It also found that medications are responsible for 34 percent of anaphylactic cases, food is responsible for around 31 percent, and insect stings for 20 percent. However, in infants, food is responsible for 73 percent of anaphylactic cases, while medications are responsible for only about 20 percent. The fatality rate of anaphylaxis in around 0.3 percent in the United States (Allergy and Asthma Network, 2023).
Pathophysiology
Anaphylaxis involves the rapid release of several chemical mediators from the degranulation of basophils and mast cells after subsequent exposure to a certain antigen. Common causes of anaphylaxis include foods, insect stings, latex, medications, and other pharmaceutical agents such as serums or skin testing antigens. IgE cross-linking and the resulting accumulation of high-affinity receptors induce the rapid release of stored chemical mediators. The inflammatory response is then facilitated by TNF-alpha (tumor necrosis factor) as a pre-formed and late-phase reactant (McLendon & Sternard, 2023).
The physiology of the released chemical mediators varies in the anaphylactic response. Histamine increases vasodilation and vascular permeability, resulting in reduced blood flow to the tissues. The body tries to compensate for this by increasing the heart rate and cardiac contraction. Prostaglandin D acts as a bronchoconstrictor that impacts both the cardiac and pulmonary vascular constriction. This prostaglandin also contributes to the reduction in blood flow to the tissues due to peripheral vasodilation. Leukotrienes contribute to vascular permeability and bronchoconstriction and induce alterations in the airway. Flushing, angioedema, urticaria, mucosal inflammation and edema, and hypotension may also be a result of the physiologic effects from these chemical mediators. The platelet-activating factors also function as a bronchoconstrictor and intensify vascular permeability (McLendon & Sternard, 2023).
Clinical Manifestations
Anaphylaxis reactions include multiple organ systems at once and may range from mild to moderate to severe. Generally, the faster the onset of symptoms, the more severe the reaction is. Subsequent reactions may not be as severe as the first. The severity is dependent on the degree of allergy and allergen dose exposure. Clinical manifestations of anaphylaxis are summarized in (Table 24.4).
| Reaction | Clinical Manifestations |
|---|---|
| Mild | Peripheral tingling, warm sensations, and a sense of fullness in the throat and mouth. Periorbital swelling, sneezing, nasal congestion, pruritus, and tearing from the eyes may also occur. This category of symptoms typically begins within the first two hours after exposure. |
| Moderate | May include all of the mild symptoms, with the addition of anxiety and flushing. Some moderate reactions may be more severe and include edema of the airways or larynx, dyspnea, wheezing, cough, and bronchospasm. This category of symptoms also generally begins within the first two hours of exposure. |
| Severe | Also referred to as anaphylactic shock. This type of reaction has a rapid onset and includes any symptoms from the mild or moderate categories. Those symptoms rapidly progress to bronchospasm, severe dyspnea, edema of the larynx, cyanosis, and hypotension. Other symptoms include dysphagia, seizures, abdominal cramping, vomiting, and diarrhea may also occur. Untreated anaphylaxis can lead to respiratory arrest and coma. |
Assessment
Assessment of anaphylaxis includes monitoring the patient for signs and symptoms of an anaphylactic reaction, as previously described. This assessment should include airway, breathing, circulation, level of consciousness, and exposure of the skin. Allergy testing may also be necessary to identify the allergen.
Diagnostics and Laboratory Values
Diagnostic tests to identify an allergen include skin tests, total serum IgE, complete blood count with differential, and eosinophil count. A blood test to check the amount of tryptase may also be used in the diagnosis of anaphylaxis. This enzyme is mainly found in mast cells and can be elevated up to three hours after an anaphylactic reaction. Plasma histamine levels and SC5b-9, a terminal compliment complex, may also be elevated after a severe reaction. Other diagnostics and laboratory values include vital signs, labs to assess the functionality of organs that may be impacted by the reaction, and x-rays or CT scans to assess those organs for damage or improvement.
Nursing Care of Patients with Anaphylaxis
Anaphylaxis is a life-threatening condition that occurs immediately after exposure to an allergen. Acute nursing care should be rapidly initiated to increase the patient’s survival rate. Immediate treatment includes administration of any ordered medication, airway assessment and management, and circulation support.
Recognizing and Analyzing Cues
Per the Clinical Judgment Measurement Model, part of the nursing process includes recognizing and analyzing cues. When it comes to anaphylactic reactions in an acute care setting, the nurse must assess the patient for any signs and symptoms of anaphylaxis in order to quickly intervene. The nurse should assess airway, breathing, vital signs, signs of increasing edema, and respiratory distress. If the patient is able to speak, the nurse should also ask if they are experiencing any difficulty breathing, any sudden changes in how they feel, or any other type of discomfort. The nurse should also be aware of when the symptoms started and when exposure to the relevant medication, food, or other allergen happened, and document this information.
Prioritizing Hypotheses, Generating Solutions, and Taking Action
If after analyzing cues the nurse determines the patient is in anaphylaxis, the nurse must promptly prioritize interventions. The nurse must notify the rapid response team or the provider per facility policy. Rapid interventions include intubation, emergency medication administration, intravenous line insertion, fluid administration, and oxygen administration, which may be necessary when the patient is experiencing cyanosis, wheezing, or dyspnea. Medications that may be administered during anaphylaxis include epinephrine, which should be injected as a 1:1,000 dilution subcutaneously in the thigh. A much lower concentration may be given continuously through intravenous solution following the initial subcutaneous injection. Epinephrine works quickly to improve breathing and blood pressure by causing vasoconstriction. It also quickly reverses urticaria and reduces edema that may occur.
In addition to epinephrine, antihistamines and corticosteroids may be given. Other vasopressor agents, such as norepinephrine, dopamine, and vasopressin, and other volume expanders, such as lactated Ringer’s and normal saline, may also be administered to maintain blood pressure and hemodynamic status. Patients with bronchospasms, asthma, or cardiopulmonary obstructive diseases may be given aminophylline and corticosteroids to improve airway patency and function. Other immediate interventions include discontinuing or removing the medication or other allergen. In the event of cardiac arrest, cardiopulmonary resuscitation (CPR) will need to be performed.
Link to Learning
Hamilton Health Sciences provides an excellent resource on how to use an EpiPen for patients at risk of anaphylaxis and their families. There is also a video demonstrating how to administer an EpiPen to oneself or others.
Evaluation of Nursing Care for Patients with Anaphylaxis
Evaluation is an essential part of the nursing process. The nurse should compare observed outcomes against expected outcomes. This allows the nurse to evaluate for signs of improvement, decline, or no change. The nurse would then use their judgment to assess whether the interventions were effective or if other interventions are needed. Documentation is required to include each intervention given and the patient’s response.
Evaluating Outcomes
The nurse should evaluate the effectiveness of all interventions to determine if any other interventions are necessary. For example, if the patient experienced difficulty breathing, the nurse should reassess the patient’s respiratory status for improvement. For example, the nurse will want to assess for improvements with wheezing or labored breathing. The nurse should check for improvements with the rate and oxygen saturation. The nurse should also assess whether any medications administered had the desired effect. If epinephrine was given, the nurse should reassess the patient’s vital signs; for example, the patient should have an increase in blood pressure and heart rate.
Medical Therapies and Related Care
Patients who have experienced anaphylaxis and have received epinephrine should be taken to an emergency room if they are not already present in a hospital setting; once there, they should be monitored for four to eight hours for rebound or delayed reactions (Tupper & Visser, 2010). Patients with severe allergic reactions may be prescribed an EpiPen in the event of re-exposure to the allergen. Those individuals may also be advised to wear a medical alert bracelet.
Once the patient has recovered, the nurse should provide education to notify the patient of what happened and why they should notify their other health care facilities of the allergy. The patient and their family members should be taught how to use an immunotherapy and be able to demonstrate the proper administration. The patient and their family should also be aware of the need call 911 in order to receive care after anaphylaxis and be monitored for rebound or delayed reactions.