Anaphylaxis

Anaphylaxis can begin with a few hives and then progress to airway obstruction or shock. The nurse does not wait for a laboratory result or for every classic finding to appear. A rapid reaction after a likely trigger is diagnosed from the pattern: skin or mucosal involvement plus respiratory or cardiovascular compromise, two or more affected systems after likely exposure, or hypotension after exposure to a known allergen. The physiology explains the urgency. Mediator release dilates blood vessels and makes them leak, narrows the bronchi, and swells upper-airway tissues. Epinephrine reverses these threats more directly than any adjunct, so it is given intramuscularly in the anterolateral thigh without waiting for an antihistamine, corticosteroid, or bronchodilator. In U.S. practice, the LVN/LPN follows applicable state law, standing orders or protocols, and facility policy while activating emergency help and preparing for escalation. The sequence is recognition, epinephrine, airway and circulatory support, and repeated reassessment.