Final answer:
The nurse should notify the provider when a client is unable to void after a total hip arthroplasty.
Step-by-step explanation:
The nurse should take the first action to notify the provider. Inability to void after a total hip arthroplasty may indicate a urinary retention or a complication related to the surgery. The provider should be notified so they can assess the client's condition and determine the appropriate intervention. It is important to involve the provider in decision-making to ensure the client's safety and well-being.