A client comes to the emergency department in acute decompensated heart failure. The client is very anxious, with a respiratory rate of 30/min and pink, frothy sputum. After placing the client on oxygen via nasal cannula, which of these actions is the next priority? 1. Administer digoxin 0.25 mg 2. Administer furosemide 40 mg IV push 3. Initiate dopamine infusion at 5 mcg/kg/min 4. Obtain blood sample for arterial blood gases