Final answer:
The nurse should assess the client's anxiety level and provide emotional support during the administration of packed RBCs.
Step-by-step explanation:
When a client becomes anxious during the administration of packed red blood cells (RBCs), it is important for the nurse to assess the client's anxiety level and provide emotional support. This can be done by acknowledging the client's feelings, offering reassurance, and utilizing relaxation techniques if appropriate. The nurse should also closely monitor the client for any signs of an adverse reaction to the transfusion.