Hypercalcemia
A diagnostic and treatment approach
UCI Internal Medicine – Mini Lecture
Hypercalcemia objectives
• Identify true hypercalcemia
• Understand basic calcium regulation
• Understand the most common etiologies
• Have a clear diagnostic and workup plan
• Understand acute management
Initial evaluation
• A 68 year-old female with no PMH or home
meds is brought to the ER by family with
altered mental status, nausea, and diffuse
bony pain.
Initial Evaluation
• VS unremarkable. A&Ox1, tries to get out of
bed and is distracted. Rest of exam normal.
Labs are normal except below:
10
139
111
3.8
20
12
1
104
1.4
1.8
Albumin= 1.0
Corrected Calcium = (0.8 * (Normal Albumin - Pt's Albumin)) + Serum Ca
What is patient’s corrected calcium?
Calcium regulation:
• PTH= increases calcium
– Release of bone Ca stores
– Increase renal tubular Ca resorption
– Increase production of activated Vit D by increased kidney
hydroxylase
• Vitamin D= increases calcium
– Needs to be activated to active form (calcitriol)
– Increases calcium absorption in gut
• Calcitonin= decreases calcium
– Slows down osteoclasts, decreases bone resorption
– Increase renal calcium clearance
Common causes of
hypercalcemica
• PTH mediated
– Primary hyperparathyroidism
• Non-PTH mediated
– PTHrp, vitamin D intoxication, granulomatous disorders,
osteolytic bone metastases, malignancy
• Medications
– Thiazide diuretics, lithium
• Misc
– Hyperthyroid, immobilization, Milk-alkali, etc…
Treatment: Mild and Moderate
• Mild (<12): No acute tx necessary
– Avoid thiazides and lithium, volume depletion
– Low calcium diet
• Moderate (12-14): May or may not require tx
– If mildly symptomatic (constipation), no immediate
therapy needed
– Treat if severely symptomatic (ie mental status changes)
Treatment: Severe Hypercalcemia
(>14)
• Normal Saline (200cc/hr, adjust for UOP 100150cc/hr)
• Calcitonin 4 IU/kg q6-12 hrs (if Ca>14)
• Bisphosphonates (Reclast 4mg IV over 15 mins)
• Especially for excessive bone resorption/malignancy
• Dialysis if above measures fail
Monitor with Q8 serum calcium levels
Treat Underlying Cause
• Multiple Myeloma
• Squamous Cell Cancer
• Gynecologic Cancer
• Sarcoidosis
• Tuberculosis
• Thyrotoxicosis
• Pituitary Adenoma
• Multiple Endocrine Neoplasia
Back to the case
• Admitted to medicine
• PTH 77 (normal 11-55) Tc99m-sestamibi
demonstrated a single parathyroid adenoma
• Referred to surgery for parathyroidectomy
Hypercalcemia objectives
• Identify true hypercalcemia
• Understand basic calcium regulation
• Understand the most common etiologies
• Have a clear diagnostic and workup plan
• Understand acute management
Take home points
• Remember to correct calcium based on
albumin levels
• Calcium regulation based on multiple factors
including PTH, Vitamin D, Calcitonin
• Primary hyperparathyroidism and malignancy
are the most common causes
Take home points
• Check PTH first, if elevated likely primary
hyperparathyroidism
• If PTH not elevated, check vitamin D (both 25OH and 1,25-OH)
• Treat all symptomatic patients with IVF
– Calcitonin, bisphosphonates if warranted