A 56-year-old man is admitted to the ED because of shortness of breath. He has a history of congestive heart failure, myocardial infarction, and hypertension. Assessment findings reveal the following: blood pressure 220/110 mmHg, pulse rate 100 beats/minute-full and bounding, and respiration rate 34 breaths/minute, deep, fast, and labored. Auscultation reveals pericardial friction rub and crackles in both lung bases. EKG monitoring reveals normal sinus rhythm with tall, tented T waves. The nurse notes that the patient has distended jugular veins and edema of the hands, feet, periorbital areas, and sacrum. Indwelling urinary catheterization yields 20 mL of dark amber urine. Arterial blood gas studies show PH 7.25, PO2 60 mmHg, PCO2 36 mmHg, and HCO3 – 14 mEq/L. Laboratory results reveal a serum BUN level of 50 mg/dL and a serum creatinine level of 5.5 mg/dL. The physician diagnoses acute renal failure (ARF). The physician determines that hemodialysis is necessary for this patient. The nurse should explain to the patient that: