A nurse is monitoring a client who is receiving a blood transfusion. The nurse notes the client has developed a sudden onset of respiratory wheezing. Which of the following actions should the nurse perform first?

A. Stop the procedure: Stopping the blood transfusion immediately is the priority to prevent further exposure to the potentially harmful blood product causing the wheezing. This action helps minimize the risk of progression to a more severe transfusion reaction or anaphylaxis. B. Administer an antihistamine: Antihistamines may relieve allergic symptoms but should only be given after the transfusion is stopped and the client is assessed. Administering medication without stopping the transfusion first could worsen the reaction. C. Administer oxygen: Providing oxygen supports the client’s respiratory function during wheezing, which may indicate hypoxia. Oxygen administration is important but secondary to stopping the transfusion to eliminate the cause. D. Initiate an infusion of 0.9% sodium chloride using new tubing: Starting a saline infusion with new tubing helps maintain IV access and prevent clotting after stopping the transfusion. This action is necessary but follows stopping the transfusion as the first priority.