Anaphylactic Shock nursing care: what to assess and what to do first

The clinical picture

Anaphylaxis develops within minutes of exposure to an allergen: a drug, a food, a venom, latex, or contrast dye. The reaction is systemic and IgE-mediated, releasing histamine and other mediators that cause vasodilation, increased capillary permeability, bronchoconstriction, and laryngeal oedema all at once. What looks like a skin reaction can become airway obstruction and distributive shock within a single patient encounter.

The presentation is fast and multi-system: urticaria and flushing, throat tightness and stridor, wheeze, hypotension, tachycardia, and a sense of impending doom the patient will often describe unprompted. In hospital, the trigger is frequently a first dose of IV antibiotic, a contrast agent, or a blood product, so anaphylaxis has to be on the differential the moment a patient deteriorates during or shortly after infusion.

Assessment: what to look for and in what order

Airway first. Check for stridor, hoarseness, drooling, and swelling of the lips, tongue, or uvula, because laryngeal oedema can close the airway before hypotension becomes obvious. Move to breathing next: respiratory rate, wheeze, accessory muscle use, and oxygen saturation. Then circulation: blood pressure, heart rate, capillary refill, and level of consciousness, since hypotension from vasodilation and fluid shift can arrive rapidly.

Skin findings, urticaria, angioedema, and flushing, are supportive but not required for diagnosis, and a patient can be in anaphylaxis with minimal skin signs. Ask about exposure in the last several minutes: a new medication, a transfusion, a food, an insect sting. Document the time of onset and the suspected trigger, both for immediate care and for the allergy record that follows the patient afterward.

Immediate interventions

Give intramuscular epinephrine into the lateral thigh (vastus lateralis) as the first action, not oxygen, not an antihistamine, not a steroid. This is the single fact that separates a correct response from a delayed one. IM injection into the thigh has faster, more reliable absorption than deltoid IM or subcutaneous routes, and epinephrine is the only drug that reverses bronchoconstriction, laryngeal oedema, and vasodilation together.

Stop the suspected trigger immediately, if an infusion is running, if a stinger is in place. Call for help and prepare for repeat epinephrine dosing every five to fifteen minutes if there is no response, following your institution's protocol. Position the patient supine with legs raised if hypotensive, or sitting if breathing is the dominant problem, but not upright and immobile if hypotension is present, as sudden standing can cause circulatory collapse.

Establish IV access, apply high-flow oxygen, and start rapid IV fluids for hypotension. Antihistamines (such as diphenhydramine) and corticosteroids are given after epinephrine, to address itching and to reduce the risk of a biphasic reaction. Neither drug acts fast enough, or on the right pathway, to reverse airway closure or shock, and giving them instead of epinephrine is the most dangerous error in this scenario.

Ongoing nursing management

Continuous cardiac and pulse oximetry monitoring is required, along with frequent blood pressure checks, because symptoms can recur hours later in a biphasic reaction even after the initial response settles. Keep the patient on monitored observation, typically four to six hours minimum, longer if the initial reaction was severe or airway involvement was significant.

Have airway equipment and further epinephrine at the bedside for the duration of observation. Reassess airway patency and breath sounds at each vital sign check rather than relying on the initial improvement. If a bronchodilator was given for persistent wheeze, document response separately from the epinephrine effect, since they act on different aspects of the reaction.

Patient and family education

Every patient who has had anaphylaxis needs a prescription for an epinephrine auto-injector, and needs to be shown how to use it, not just told to carry it. Teach injection into the outer mid-thigh, through clothing if necessary, and to call emergency services immediately after use even if symptoms improve, because a second dose or hospital-level care may still be needed.

Identify and document the trigger clearly in the record and with the patient, including cross-reactive substances the patient may not have connected, such as related drug classes or foods. Advise medical alert identification and a written action plan. Family members or caregivers should also learn the auto-injector technique, since the patient may not be able to self-administer during a severe reaction.

How this appears on the NCLEX

NCLEX questions on anaphylaxis are built to catch the test-taker who reaches for oxygen or diphenhydramine first. The correct first action is almost always IM epinephrine, and the correct site is the lateral thigh. If a question lists epinephrine alongside an antihistamine or steroid as simultaneous options, prioritise epinephrine as the first nursing action.

Expect questions that combine a scenario, new IV drug, insect sting, contrast dye, with early signs like throat tightness or hives, asking you to recognise anaphylaxis before it is named. Other items test priority-setting frameworks (airway-breathing-circulation) applied to a distributive shock picture, and post-reaction education about auto-injector use and observation time.