A nurse is caring for a patient who is experiencing anaphylaxis after receiving a penicillin injection. The patient's blood pressure is 70/40 mmHg, heart rate is 140 bpm, and the patient is experiencing severe bronchospasm with stridor. What is the nurse's priority action?

Epinephrine is the first-line treatment for anaphylaxis and must be administered immediately to counteract life-threatening systemic reactions. Other interventions like oxygen, IV access, and airway management are supportive but secondary.

Understanding the Priority: The ABCs and Anaphylaxis

In the setting of anaphylaxis with severe hypotension (70/40 mmHg), tachycardia (140 bpm), and significant respiratory distress with stridor, the clinical picture represents a life-threatening, multi-system crisis. The NCLEX-RN prioritization framework requires you to address the most critical physiological need first. While airway, breathing, and circulation are all compromised, the underlying driver of this rapid deterioration is massive vasodilation, increased vascular permeability, and bronchoconstriction. The single intervention that simultaneously targets all these mechanisms—and prevents progression to fatal circulatory collapse and airway obstruction—is the immediate administration of intramuscular epinephrine.

Why Epinephrine is the Priority Action

Epinephrine is unequivocally the first-line therapy for anaphylaxis because it is the only agent that directly counteracts the pathophysiological cascade of the reaction. The 2025 Korean Guidelines for CPR and First Aid, as well as global consensus, emphasize that delayed administration is the primary driver of preventable deaths [1,3]. Here is the breakdown of its life-saving effects that make it the priority over all other interventions:

- Reverses Cardiovascular Collapse: The patient’s shock state (hypotension and reflex tachycardia) results from profound vasodilation and fluid shift from the intravascular to the interstitial space. Epinephrine is a potent alpha-1 adrenergic agonist, causing immediate vasoconstriction. This increases systemic vascular resistance, raises blood pressure, and reduces mucosal edema, including in the upper airway [1,3].
- Reverses Bronchospasm: The severe bronchospasm and stridor are caused by bronchial smooth muscle constriction. Epinephrine is a potent beta-2 adrenergic agonist, which causes immediate bronchodilation, relieving the lower airway obstruction [1,3].
- Stops Further Mediator Release: Epinephrine acts on mast cells and basophils to inhibit the further release of histamine, leukotrienes, and other inflammatory mediators that are driving the anaphylactic reaction .

Administering epinephrine 1:1000 (0.3-0.5 mg) intramuscularly into the anterolateral thigh is the most rapid and effective route in a crashing patient without IV access, achieving peak plasma levels faster than subcutaneous administration. Every minute of delay in administering epinephrine increases the risk of a fatal outcome [1,3].

Why Other Options Are Not the Priority

While the other listed actions are critically important, they are secondary to the immediate administration of epinephrine. Understanding this hierarchy is key for NCLEX-RN prioritization questions.

- Option 1 (Administer high-flow oxygen): This is a critical supportive measure for hypoxia, but it does nothing to reverse the underlying bronchoconstriction, vasodilation, or airway edema. The patient’s stridor indicates a narrowing upper airway that oxygen alone cannot fix. Epinephrine must be given first to open the airway and restore perfusion, making oxygenation effective ^[1].
- Option 2 (Establish IV lines and fluid resuscitation): Fluid resuscitation is essential for managing the distributive shock of anaphylaxis, as the patient is profoundly volume-depleted due to vascular leak. However, fluid alone will not overcome the profound vasodilation without the vasoconstrictive effect of epinephrine. The priority is to administer the drug that will restore vascular tone, after which aggressive fluid resuscitation with large-bore IVs should be initiated rapidly [1,3].
- Option 3 (Prepare for emergency intubation): Stridor is a sign of impending airway obstruction, and preparation for a difficult airway is a high priority. However, the first-line pharmacological intervention to reduce laryngeal edema and bronchospasm is epinephrine. Its alpha-1 agonist effect can rapidly reduce upper airway swelling, potentially averting the need for intubation. If intubation becomes necessary, it must be performed after or concurrently with epinephrine administration, as the drug is needed to stabilize the patient for the procedure [1,3].

Clinical Safety and Rationale

A key concern for new nurses is the fear of causing harm with epinephrine, especially in patients with cardiovascular comorbidities. A case report documented a hypertensive emergency and brainstem hemorrhage temporally associated with intramuscular epinephrine in a patient with poorly controlled hypertension and end-stage renal disease . While this is a serious adverse event, it is critical to understand the risk-benefit analysis in anaphylaxis: the risk of death from untreated anaphylaxis is immediate and absolute. The recommended intramuscular dose of 0.3-0.5 mg of 1:1000 concentration is the standard of care and is life-saving. The potential for adverse cardiovascular effects, while real, does not change the fact that epinephrine is the non-negotiable, first-line priority action. The nurse must administer it without delay and then monitor for both therapeutic and adverse effects [2,3].