A 58-year-old homeless man with long-standing insulin-treated type 2 diabetes has been diagnosed with right lower extremity cellulitis. He has taken a prescribed oral antibiotic for the past week but...

A 58-year-old homeless man with long-standing insulin-treated type 2 diabetes has been diagnosed with right lower extremity cellulitis. He has taken a prescribed oral antibiotic for the past week but has not noticed much improvement. For the past 2 days, he has complained of intermittent fevers and chills, nausea with poor oral intake, and proximally spreading erythema over his right leg. On the evening of admission, a friend notices that he is markedly confused and calls 911. In the emergency room, he is oriented only to his name. The patient is tachypneic, breathing deeply at a rate of 24/min. He is febrile at 38.8°C. He is normotensive, but his heart rate is elevated at 112 bpm. On examination, this patient is a delirious, unkempt man with a fruity breath odor. His right lower extremity is markedly erythematous and exquisitely tender to palpation. Serum chemistries reveal a

glucose level of 488 mg/dL, potassium of 3.7 mEq/dL, and sodium of 132 mEq/L. Urine dipstick is grossly positive for ketones.

. What are important issues to consider in replacing electrolytes in this patient?