A 35-year-old female client has returned to her room following surgery on her right femur. She has an IV of D5 1/2 NS infusing at 125 cc/hr, and is receiving morphine sulfate 10-15 mg IM q4h prn for pain. The client last voided 5 1/2 hours ago when she was given her preoperative medication. To monitor and promote the return of urinary function after surgery, the nurse should: