Hypercalcemia
Evaluation:
- verify with repeat measurement that there is a true increase in the serum calcium concentration (total calcium corrected for albumin or ionized calcium)
- Compare with previous values if available
- Clinical evaluation, including duration of hypercalcemia, presence or absence of symptoms, family history, and medications, may help determine the etiology of hypercalcemia
Causes:
- primary hyperparathyroidism
- malignancy (PTH related peptide, ectopic production of 1,25, dihydroxyvitamin D, osteoclast activating factor
- lytic bone mets
- non parathyroid endocrine disorder
- thyrotoxicosis, pheochromocytoma, adrenal insufficiency, VIP-producing tumor
- granulomatous disease (1,25 dihydroxyvitamin D excess)
- sarcoidosis, tuberculosis, histoplasmosis, coccidiomycosis, leprosy
- medications (thiazide diuretics, lithium, estrogens, antiestrogens)
- milk-alkali syndrome
- vitamin A or D intoxication
- familial hypocalciuric hypercalcemia
- immobilization
- parenteral nutrition
- acute and chronic renal failure
Signs:
- "Stones, moans, groans, with psychic overtones*.
- Renal: polyuria (nephrogenic DI), nephrolithiasis, renal failure, ectopic calcification
- Gl: anorexia, nausea, vomiting, constipation
- Neuro: weakness, fatigue, confusion, stupor, coma
- ECG: Shortened QT
Treatment:
- avoid factors that can aggravate hypercalcemia, including thiazide diuretics and lithium carbonate therapy, volume depletion, prolonged bed rest or inactivity, calcium and/or vitamin D supplements, and a high-calcium diet (>1000 mg/day)
- Mild hypercalcemia - asymptomatic or mildly symptomatic with with serum calcium level of 12 and 14 mg/dL [3 to 3.5 mmol/L]) may not require immediate therapy
- Moderate hypercalcemia - Asymptomatic or mildly symptomatic individuals with chronic moderate hypercalcemia (calcium between 12 and 14 mg/dL [3 to 3.5 mmol/L]) may not require immediate therapy
- Severe hypercalcemia - serum calcium levels of >14 mg/dL [3.5 mmol/L]) or symptomatic (eg, lethargy, stupor) require aggressive therapy.
- → Initial therapy of severe hypercalcemia includes the simultaneous administration of intravenous (IV) isotonic saline, subcutaneous calcitonin, and a bisphosphonate (typically, IV zoledronic acid)
- Correct dehydration, increase renal calcium excretion, decrease bone resorption, and treat the underlying disorder.
- IV hydration, initial rate is 200 to 300 mL/hour that is then adjusted to maintain the urine output at 100 to 150 mL/hour
- In individuals with renal insufficiency or heart failure, careful monitoring and judicious use of loop diuretics (after intravascular volume has been repleted) may be required to prevent fluid overload. IV furosemide
- Specific treatment in approximate desirability of use:
- For immediate, short-term management in severe hypercalcemia (Ca >14 mg/dl) and symptomatic patients (lethargy, stupor), administer Calcitonin in combination with NS hydration and Bisphosphonates. Initial Calcitonin dose is 4 units/kg, administered SQ or IM. Repeat serum calcium in 4-6 hrs. If lowering of calcium levels is noted, continue 4 U/kg BID for 24-48 hrs. May increase to 8 U/kg Q12H or Q6H for 24-48 hrs if response is not satisfactory with 4 U/kg BID.
- Among IV bisphosphonates, Zaldronic Acidis preferred over pamidronate (60 to 90 mg over 2 hours) because it is superior to pamidronate in reversing hypercalcemia related to malignancy. The initial dose is 4 mg IV over 15 minutes.
- Pamidronate 15-45 mg IV as single IV infusion or 90 mg over 2-24 hours would be another option for treatment
https://www.uptodate.com/contents/treatment-of-hypercalcemia?search=hypercalcemia&source=search_result&selectedTitle=2~150&usage_type=default&display_rank=2