The nurse is caring for a patient who has undergone major abdominal surgery. 4 hours post-op Urine output 45 mL/hr BP 120/80 mm Hg HR 90 beats/min Weight 97.5 kg 24 hours post-op Urine output 20 mL/hr for past 2 hours BP 100/60 mm Hg HR 110 beats/min Weight 99 kg According to the 4-hour post-op assessment data and the 24-hour assessment data, the nurse should: