A 59-year-old woman with peripheral vascular disease, hypertension, and type II diabetes mellitus is admitted to hospital for a 5-hour history of a cold, left leg. Her medications are lisinopril, metformin, atorvastatin, and aspirin. She has smoked one pack of cigarettes daily for 40 years. Blood pressure is 150/90. Pulses are reduced in the left lower extremity. Serum creatinine is 1.3 mg/dL; BUN is 25 mg/dL. She undergoes angiography of the left popliteal artery. 24 hours later, her serum creatinine is 3.3 mg/dL; BUN is 52 mg/dL. Which of the following measures prior to the angiography is most likely to have prevented this patient’s worsening azotemia?
2L of 0.9% NaCl
Discontinuation of metformin
Pretreatment with mannitol
Pretreatment with prednisone and diphenhydramine
There are no specific preventive measures
