Diagnosis
Hypercalcemia algorithm reviewed (AAFP).
H&P
Causes of hypercalcemia.
Common presentation.
Diagnostic studies
*An isolated elevated calcium level should be repeated before further workup is indicated. Order CMP with ionized calcium.
Treatment
1st-line
–Hydration with Normal Saline IV is the initial treatment of choice. This helps to correct the volume depletion that is invariably present and to enhance renal calcium excretion. Will start IV fluids at 150 to 200 cc /hr if patient’s heart and volume status tolerates and then back down to 125 mL/hr when the patient is hydrated.
–IV bisphosphonates (Zoledronic acid or pamidronate) only after the patient is already euvolemic.
2nd-line.
–Salmon calcitonin (4 international units/kg) IM or SC q12 hours. May increase the dose to 6 to 8 international units/kg every six hours.
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Caution: Loop diuretics reserved only for patients with volume overload. Loop diuretics can aggravate volume depletion and are not very effective alone in promoting renal calcium excretion. As such, they should be avoided unless necessary.
“Isotonic saline corrects possible volume depletion due to hypercalcemia-induced urinary salt wasting and, in some cases, vomiting. Hypovolemia exacerbates hypercalcemia by impairing the renal clearance of calcium.
Calcitonin reduces the serum calcium concentration by increasing renal calcium excretion and, more importantly, by decreasing bone resorption via interference with osteoclast function. Salmon calcitonin (4 international units/kg) is usually administered IM or SC every 12 hours; doses can be increased up to 6 to 8 international units/kg every six hours.
Zoledronic acid is considered by many to be the agent of choice for malignancy-associated hypercalcemia because it is more potent and effective than pamidronate. It can be given over a shorter time period (15 minutes compared with two hours).”
Further Reading
https://www.aafp.org/afp/2013/0815/p249.html