The Answer: B
Hypercalcemia is a common complication of
malignancies. The etiology of hypercalcemia is enhanced bone resorption. This
reflects: release of parathyroid hormone (PTH)-related peptide (PTHrP), local
release of bone resorptive cytokines by lytic tumors, and production by the
tumor of 1,25 Vitamin D3.
Treatment comprises of: hydration, forced alkaline
diuresis, use of calcitonin, and administration of bisphosphonates. Bisphosphonates are effective for the
management of chronic hypercalcemia but are contraindicated in patients with
moderate to severe renal insufficiency. Even if one considered using a
bisphosphonate it would be after other strategies had been exhausted. Hydration
is key.
In this case, the patient appears to have been well hydrated (note the
absence of orthostatic changes, the normal heart rate, and the moist mucous
membranes). Hemodialysis is also an effective therapy for the treatment of
hypercalcemia but may not be appropriate as yet (i.e., as the first step).
The
next step in management should be to start calcitonin, which is effective over
a few hours, and mithramicin. Corticosteroid administration could also be
considered.
A 64-year old woman with a history of breast cancer is admitted to the hospital with confusion, nausea and vomiting. She was doing well until 1 week ago when she noticed a marked increase in her urine output. She has a past medical history of Her2+ breast cancer diagnosed 2 years previously and she is status post adjuvant chemotherapy, lymph node clearance left axilla, and radiation therapy. Her physical examination shows her to have a blood pressure of 118/70 mmHg with no orthostatic change and a heart rate of 82 beats per minute. Her mucous membranes are moist. Except for a left axillary wall scar and moderate hepatomegaly, the rest of the physical examination is unremarkable. Her serum calcium adjusted for her serum albumin is 14.2 mg/dL. Her other electrolytes are normal. Her BUN is 68 mg/dL and her serum creatinine is 5.2 mg/dL. She has been hydrated with 3 liters of 0.9% saline administered at 100 mL/hr. Her repeat serum calcium is 12.9 mg/dL and she remains confused. You are asked to provide additional recommendations regarding management.
The most appropriate next best step is to:
A.) Start the patient on a bisphosphonate
B.) Start this patient on calcitonin and mithramycin
C.) Continue the intravenous hydration
D.) No treatment
E.) Begin hemodialysis
