Which of the following is the first intervention when a blood transfusion reaction is suspected?

In the event of a suspected blood transfusion reaction, the first critical step is to stop the transfusion immediately. This action is essential because continuing the transfusion can exacerbate the reaction, leading to potentially life-threatening complications. Stopping the transfusion prevents further transfused blood from entering the patient's system, allowing immediate assessment and intervention without further exposure to the incompatible blood product.

Following the cessation of the transfusion, it is appropriate to manage the patient's symptoms and initiate further care, which includes notifying the healthcare provider, monitoring vital signs, and possibly administering medications such as antihistamines if an allergic reaction is suspected. However, the immediate priority is always to halt the transfusion to ensure the safety and well-being of the patient.