What is the priority action for a nurse attending to a client with a severe allergic reaction during a transfusion?

The priority action for a nurse attending to a client with a severe allergic reaction during a transfusion is to stop the transfusion immediately. This action is critical because continuing the transfusion can exacerbate an already dangerous situation, increasing the risk of further complications such as anaphylaxis or severe hypotension. Stopping the transfusion allows the nurse to halt the introduction of the suspected allergen, which is crucial in managing the patient's safety.

In addition to stopping the transfusion, the nurse would typically take further steps, such as assessing the patient's condition, implementing appropriate interventions like administering antihistamines or epinephrine if indicated, and monitoring vital signs closely. However, the immediate priority is to prevent further exposure to what may be causing the allergic reaction.

While starting oxygen therapy may be necessary if the patient exhibits signs of respiratory distress, it should follow the initial action of stopping the transfusion. Notifying family members and administering a pain reliever are also important but are not immediate priorities in the context of a severe allergic reaction during a transfusion.