A nurse reviews the laboratory reports before health care provider rounds. The serum calcium level of a client with multiple myeloma is 14.6 mg/dL (9-10.5 mg/dL). Which treatment should the nurse anticipate?

Rationale: A. Starting oral calcium supplements is inappropriate in this client. The client’s calcium level is already critically elevated at 14.6 mg/dL, which is considered severe hypercalcemia. Administering calcium supplements would further raise serum calcium, increasing the risk of life-threatening complications such as cardiac arrhythmias, altered mental status, muscle weakness, and acute kidney injury. Calcium supplementation is only indicated for clients with hypocalcemia, not hypercalcemia. B. Withholding fluids is unsafe in a client with hypercalcemia. Adequate hydration is critical because hypercalcemia can cause nephrogenic diabetes insipidus, leading to polyuria, dehydration, and further elevation of calcium levels. Restricting fluids would exacerbate these issues, potentially worsening renal function and increasing the risk of kidney failure. C. Administering intravenous fluids at 200 mL/hour is the correct intervention. IV hydration with isotonic saline expands intravascular volume, increases glomerular filtration rate, and promotes renal calcium excretion. This approach helps lower serum calcium levels safely and prevents complications such as acute kidney injury and cardiac disturbances. In severe hypercalcemia, aggressive IV hydration is the first-line treatment, often followed by medications like bisphosphonates or calcitonin if additional calcium reduction is needed. D. Giving vitamin D supplements is contraindicated in this scenario. Vitamin D increases calcium absorption from the gastrointestinal tract. Providing vitamin D to a client with severe hypercalcemia would further elevate calcium levels and could precipitate life-threatening complications, including cardiac arrhythmias and neurological changes such as confusion or lethargy.