Final answer:
The nurse's priority intervention for a patient with exacerbation of heart failure in an acute care unit is to assess respiratory status to quickly identify and address any signs of pulmonary edema or respiratory distress.
Step-by-step explanation:
The nurse's priority intervention for a client admitted to the acute care unit for an exacerbation of heart failure is to assess respiratory status. This is critical because patients with heart failure can quickly develop pulmonary edema, which can lead to respiratory distress. Assessing respiratory status involves monitoring the patient's breathing rate, effort, and listening to lung sounds, which can indicate fluid accumulation and requires prompt intervention. While the other options are important aspects of care (monitoring electrolyte levels, administering intravenous fluids, and inserting a Foley catheter), they may not be the initial priority when immediate assessment of respiratory function is crucial for preventing further complications.