A female client is admitted with a diagnosis of acute renal failure. She is awake, alert, oriented, and complaining of severe back pain, nausea and vomiting and abdominal cramps. Her vital signs are blood pressure 100/70 mm Hg, pulse 110, respirations 30, and oral temperature 100.4°F (38°C). Her electrolytes are sodium 120 mEq/L, potassium 5.2 mEq/L; her urinary output for the first 8 hours is 50 ml. The client is displaying signs of which electrolyte imbalance?
A. Hyponatremia B. Hyperkalemia C. Hyperphosphatemia D. Hypercalcemia