Hypercalcemia

Hypercalcemia – Rebecca Choudhry, Trevor Stevens

Background

  • Definition: Total serum Calcium (Ca+2) >10.5
  • REMEMBER: Most Ca+2 in the serum is bound primarily to albumin
  • In a hypoalbuminemic pt, you can correct the total Ca+2 level with the formula:
    •  
    • 0.8 x (4 – albumin level) + uncorrected Ca+2 = corrected Ca+2
  • Ca+2 > 12 can cause shortened QT interval; Ca+2 at high levels can cause 2nd and 3rd degree heart block, ventricular arrhythmias, and ST elevations mimicking MI
  • Pts with Ca+2 <12 or chronic moderate hypercalcemia are often asymptomatic
  • Severe manifestations uncommon at Ca+2 <14

 

Presentation

  • Stones, bones, thrones, belly groans, and psychiatric overtones”
    • Bone pain
    • Polydipsia/polyuria
    • Nausea/constipation
    • Depressed mood/cognitive impairment
    • Decreased level of consciousness

 

 

Management

  • Step 1: Stop any contributing medications: Ca+2 supplements, vitamin D, HCTZ
  • Step 2: Check PTH! Then check magnesium, phosphorus, total vitamin D.
  • Step 3: Determine if PTH is low or normal/high
      • Normal or ↑ PTH
        • Primary hyperparathyroidism: Ca+2 and PO4-3
        • Tertiary hyperparathyroidism (autologous secretion of PTH in CKD/ESRD)
          • PTH often > 800 with Ca+2 and PO4-3
        • Familial hypercalciuric hypercalcemia (often asymptomatic, no treatment required)
        • 24-hour urine Ca+2 < 200
      • PTH
        • Humoral hypercalcemia of malignancy: PTHrP
        • Malignancy: Bone survey for blastic lesions, skeletal survey for lytic lesions
        • Excess vitamin D intake: 25 hydroxyvitamin D
        • Granulomatous disease: 1,25 dihydroxy vitamin D, 25 hydroxyvitamin D, nl or ACE
        • Milk-alkali syndrome
        • Immobilization
        • Medications (HCTZ)
        • Thyrotoxicosis: TSH
        • Adrenal insufficiency: AM cortisol
  • Step 4: Determine if Ca+2 > 14 (corrected for albumin) or symptomatic and treat accordingly
      • If Ca+2  < 14 and asymptomatic
        • Encourage PO hydration
        • Replete volume with IV normal saline if hypovolemic
        • Address underlying cause as above
      • If Ca+2  > 12 with symptoms or Ca > 14
        • Trend Ca q8 hrs, EKG, monitor on telemetry; strict I/Os + foley catheter
        • Replete volume w/ IV NS boluses then start maintenance IVF at ~ 200cc/hr
          • Goal UOP is 100-150cc/hr
        • Add loop diuretic (Lasix) only AFTER patient is volume replete
        • Bisphosphonate:
          • Zoledronic acid 4mg IV (EGFR >60), Pamidronate 90mg IV (EGFR 15-60)
      • If Ca+2 >14 or neurologic symptoms, consider sub q (NOT intranasal!) calcitonin
        • VUMC: requires approval from an oncology or endocrine attending
          • Page VU/VA endocrine consult fellow to get approval
          • If cancer pt, page malignant heme or solid tumor fellow​​​​​​​

 

­Additional Information

  • In CHF pt, consider early addition of a loop diuretic, especially if volume overloaded
  • In ESRD pt with hypercalcemia (rare), patient with oliguric AKI not responsive to IVF, or pt with severely elevated Ca 16-18, consult endocrine and nephrology early
  • In pts with sarcoid or lymphoma, consider high dose steroids (e.g. prednisone 60 mg daily although typically only need 15-25 mg/day)