The nurse is beginning a shift on a medical-surgical unit and receives the following report on four patients. Based on the principles of prioritization using the ABCs (Airway, Breathing, Circulation) and Maslow's Hierarchy of Needs, which patient should the nurse assess first?

A 45-year-old postoperative patient complaining of incisional pain rated 8/10.

A 66-year-old diabetic with a blood glucose of 210 mg/dL waiting for discharge instructions.

A 72-year-old with pneumonia who is confused and has a respiratory rate of 32 breaths/min.

A 29-year-old with a potassium level of 3.4 mEq/L requesting assistance to the bathroom.