What should be the nurse's action if a client with a central line experiences sudden hypotension and tachycardia?

In the scenario where a client with a central line is experiencing sudden hypotension and tachycardia, clamping the central line catheter is the most appropriate action. This response is crucial because sudden hypotension and tachycardia can indicate possible complications related to the central line, such as air embolism, catheter dislodgment, or bleeding.

Clamping the central line prevents further air from entering the vascular system if there is an air embolism and can also stop additional blood loss in case of a dislodged catheter. By performing this action, the nurse helps to stabilize the situation while further assessment and intervention are planned.

The other options, such as connecting a new IV line or starting IV fluids, may not address the root cause of the hypotension and tachycardia immediately and could potentially introduce more air into the system if an air embolism is present. Notifying the family, while important, should not be prioritized over ensuring the patient’s immediate safety and stabilization.