A nurse is assisting in the care of a client who is receiving a transfusion of packed red blood cells. The client develops itching and hives. Which of the following actions should the nurse take first?

Choice A rationale Stopping the transfusion is the immediate priority when any sign of an adverse reaction occurs, such as urticaria or pruritus. These symptoms may indicate a mild allergic reaction or the beginning of a more severe anaphylactic response. By halting the infusion of the blood product, the nurse prevents further exposure to the offending allergen, thereby limiting the severity of the physiological response. This action must be performed before any other interventions to ensure patient safety and stabilization. Choice B rationale While notifying the registered nurse or the healthcare provider is a necessary step in the management of a transfusion reaction, it must follow the immediate cessation of the infusion. Communication is vital for coordinating the subsequent medical response, including orders for medications or laboratory tests to investigate the reaction. However, delay in stopping the blood while seeking help increases the volume of the allergen entering the bloodstream, which can escalate a minor reaction into a life-threatening emergency. Choice C rationale Administering diphenhydramine is a common treatment for allergic transfusion reactions to block histamine receptors and reduce itching and hives. However, this pharmacological intervention requires a provider's order and should only occur after the source of the reaction has been stopped. Giving medication while the blood is still flowing is ineffective because the underlying trigger is still being introduced into the systemic circulation. The nurse must prioritize physical intervention and assessment before administering prescribed treatments for the symptoms. Choice D rationale Obtaining vital signs is a critical component of assessing the client's status and determining the severity of the reaction, such as checking for hypotension or tachycardia. Normal ranges typically include a heart rate of 60 to 100 beats per minute and blood pressure around 120 over 80 mmHg. While assessment is fundamental to nursing care, the immediate danger posed by the continued infusion of an incompatible or allergenic substance takes precedence. Data collection follows the primary action of stopping the potential harm.