Final answer:
The immediate priority for the nurse to assess when a client presents in the emergency department with complaints of overwhelming anxiety is cardiac status.
Step-by-step explanation:
The immediate priority for the nurse to assess when a client presents in the emergency department with complaints of overwhelming anxiety is cardiac status. This is because anxiety can have physiological effects on the cardiovascular system, such as increased heart rate and blood pressure. Assessing the client's cardiac status would help determine if there are any immediate cardiac concerns that need to be addressed.