Calcium

Hypercalcemia

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Hypercalcemia, High Serum Calcium, Serum Calcium Elevation, Hypercalcemic Crisis

  • Causes
  1. Malignancy
    1. See Hypercalcemia of Malignancy
    2. Breast Cancer with bone metastases
    3. Lung Cancer
    4. Head and Neck squamous cell cancer
    5. Renal Cell Cancer
    6. Hematologic
      1. Multiple Myeloma
      2. Hodgkin's Lymphoma
  2. Paget's Disease of Bone
  3. Hyperparathyroidism
    1. Primary Hyperparathyroidism (most common cause)
    2. Multiple endocrine neoplasia (type 1 or 2A)
    3. Familial Hypocalciuric Hypercalcemia
    4. Lithium treatment
    5. Secondary Hyperparathyroidism
      1. Vitamin D Deficiency
      2. Chronic Kidney Disease (Renal Osteodystrophy)
  4. Medications
    1. Thiazide Diuretics
    2. Lithium
    3. Vitamin A toxicity
    4. Vitamin D Toxicity (e.g. 25-Hydroxyvitamin D2)
    5. Milk alkali syndrome
    6. Theophylline
  5. Endocrine
    1. Adrenal Insufficiency
    2. Thyrotoxicosis (Hyperthyroidism)
    3. Pheochromocytoma
    4. Acromegaly
  6. Other causes
    1. Familial Hypocalciuric Hypercalcemia
    2. Prolonged immobilization
    3. Granulomatous disease (Sarcoidosis, Tuberculosis)
    4. Williams Syndrome
    5. Jansen Disease (metaphyseal chondrodysplasia)
  • Symptoms
  1. Often asymptomatic
  2. Symptoms and Signs are related to Serum Calcium Levels
    1. Calcium > 11.5 mg/dl (2.9 mmol/L)
      1. Symptom onset
    2. Calcium > 13 mg/dl (3.2 mmol/L)
      1. Nephrocalcinosis
      2. Acute Renal Failure
    3. Calcium >14 mg/dl (3.5 mmol/L)
      1. Severe Hypercalcemia (or Parathyroid crisis)
  3. Cardiovascular
    1. Chest Pain
    2. Dyspnea
    3. Palpitations
    4. Syncope
  4. Gastrointestinal
    1. Anorexia
    2. Constipation
    3. Epigastric Pain
    4. Nausea
    5. Vomiting
  5. Renal
    1. Polydipsia
    2. Polyuria
    3. Renal Colic
  6. Neurologic
    1. Anxiety
    2. Confusion
    3. Fatigue
    4. Lethargy
    5. Weakness
  7. Musculoskeletal
    1. Bone pain
    2. Arthralgias
  8. Skin
    1. Pruritus (Metastatic calcification of skin)
  • Complications
  • Stones, Bones, Moans, Psychic Groans
  1. Renal ("Stones")
    1. Nephrolithiasis (Calcium Oxalate)
    2. Nephrocalcinosis
      1. Metastatic calcification renal tubules
      2. Polyuria from loss of urine concentrating function
  2. Musculoskeletal ("Bones")
    1. Osteitis fibrosa cystica (Late finding)
      1. Bone cysts from subperiosteal bone resorption
      2. "Brown tumor" in jaw
    2. Pseudogout
      1. Calcium pyrophosphate - Positively birefringent
    3. Osteoporosis
  3. Gastrointestinal ("Abdominal Moans")
    1. Peptic Ulcer Disease
      1. Calcium stimulates Gastrin release
    2. Acute Pancreatitis
      1. Calcium activates phospholipases
    3. Constipation
      1. Most common gastrointestinal symptom
  4. Neuropsychiatric ("Psychic groans")
    1. Altered Level of Consciousness or Delirium
    2. Decreased concentration and memory
    3. Personality change
    4. Psychosis
    5. Major Depression
  5. Eye
    1. Band Keratopathy (Corneal calcification)
      1. Metastatic calcification in eye limbus
  6. Cardiovascular
    1. Cardiac arrhythmia
    2. Diastolic Dysfunction
    3. Hypertension
      1. Hypercalcemia Vasoconstricts vessels
  • Imaging
  1. Calcified soft tissues
  1. Total Serum Calcium increased
    1. Total Serum Calcium > 10.5 mg/dl
  2. Confirmatory
    1. Ionized Calcium >5.6 mg/dl or
    2. Corrected Serum Calcium increased (corrected for Serum Albumin)
  • Labs
  • Hypercalcemia evaluation
  1. First-line
    1. Parathyroid Hormone
    2. 25-Hydroxyvitamin D
    3. Serum Magnesium
    4. Serum Creatinine
  2. Second-line: PTH level normal or high (PTH-dependent Hypercalcemia)
    1. Urine Calcium to Creatinine Ratio
      1. Decreased <0.01 in Familial Hypocalciuric Hypercalcemia
      2. Increased >0.01 in Primary Hyperparathyroidism, Hypercalcemia or Malignancy, MEN I
  3. Second-line: PTH level <20 pg/ml (PTH-independent Hypercalcemia)
    1. Parathyroid Hormone-related Peptide (PTHrp) increased
      1. Hypercalcemia of Malignancy
      2. Consider broad evaluation for malignancy
        1. Complete Blood Count
        2. Liver Function Tests
        3. Chest XRay
        4. Chest CT and Abdominal CT
        5. Protein electrophoresis (SPEP and UPEP)
        6. Bone Scan
        7. Mammogram
    2. 1,25 Dihydroxyvitamin D increased
      1. Lymphoma
      2. Granuloma (e.g. Sarcoidosis)
    3. 25-Hydroxyvitamin D (Calcitriol) increased
      1. Vitamin D Toxicity
  • Diagnostics
  • Evaluation
  1. General
    1. Primary Hyperparathyroidism and Hypercalcemia of Malignancy: 90% of cases
  2. Step 1: Confirm Hypercalcemia present (see labs above)
    1. Immediate management for symptomatic or severe Hypercalcemia (Serum Calcium >14 mg/dl)
  3. Step 2: Obtain history for potential causes
    1. See causes above
    2. Consider Renal Osteodystrophy
    3. Eliminate potential causative medications (Thiazide Diuretics, Lithium)
  4. Step 3: Obtain intact Parathyroid Hormone (PTH) Level
    1. PTH low: Go to Step 4
    2. PTH normal or high (PTH-Dependent Hypercalcemia)
      1. Obtain Urine Calcium to Creatinine Ratio (24 hour Urine Calcium)
      2. Urine Calcium to Creatinine Ratio normal or high
        1. Primary Hyperparathyroidism
        2. Recovery from Acute Tubular Necrosis
        3. Lithium
        4. Multiple Endocrine Neoplasia Type I (MEN I)
        5. Parathyroid carcinoma (severe Hypercalcemia and very high PTH)
      3. Urine Calcium to Creatinine Ratio <0.01
        1. Familial Benign Hypocalciuric Hypercalcemia (FBHH)
  5. Step 4: PTH-Independent Hypercalcemia
    1. Assess for malignancy and endocrinopathy
    2. Careful history and examination for tumor
    3. Tumor specific labs
      1. Parathyroid Hormone-related Peptide (PTHrp)
        1. Increased in solid tumors (see Hypercalcemia of Malignancy)
        2. Consider broad evaluation for malignancy
          1. Complete Blood Count
          2. Liver Function Tests
          3. Chest XRay
          4. Chest CT and Abdominal CT
          5. Protein electrophoresis (SPEP and UPEP)
          6. Bone Scan
          7. Mammogram
      2. Alkaline Phosphatase: Increased with bone lysis
        1. Consider bone scan
      3. Protein electrophoresis (SPEP and UPEP)
        1. Monoclonal peak in Multiple Myeloma
      4. 1,25-dihydroxyvitamin D (Calcitriol) increased
        1. Lymphoma
        2. Granuloma (e.g. Sarcoidosis)
    4. Endocrine Labs
      1. Thyroid Stimulating Hormone (Hyperthyroidism)
      2. Corticotropin Stimulation Test (Addison's Disease)
      3. Insulin-like Growth Factor 1 (Acromegaly)
    5. Reconsider medication causes of low PTH
      1. Thiazide Diuretics
      2. Vitamin D Toxicity
      3. Vitamin A Toxicity
      4. Milk-Alkali Syndrome
      5. Aluminum Intoxication
  • Management
  1. Identify and treat underlying cause
  2. Mild Hypercalcemia (Serum Calcium <12 mg/dl)
    1. Adequate Hydration (>2 Liters per day)
    2. Maximize mobility
    3. Diuretics if symptomatic
      1. Furosemide (Lasix) 40-160 mg/day
  3. Severe Hypercalcemia or Hypercalcemic Crisis (Serum Calcium >14 mg/dl)
    1. Consider also in moderate symptomatic Hypercalcemia
    2. Normal Saline 2 to 4 Liters/day for 1-3 days
      1. Adjust to obtain 200 ml Urine Output per hour
      2. Exercise caution in Congestive Heart Failure
      3. Anticipate 1-3 mg/dl drop in Serum Calcium
    3. Additional measures if refractory after hydration
      1. Lasix 10-20 mg q1-2 hours as needed
        1. Most effective agent in calcium elimination
      2. Calcitonin 4-8 IU/kg IM or SQ q6 hours for 24 hours
        1. Rapid onset, but weakest of the agents (do not use as monotherapy)
    4. Agents with specific indications
      1. Malignancy: Bisphosphonates
        1. Pamidronate (Aredia) 60-90 mg IV over 4 hours
        2. Zoledronic acid (Zometa) 4 mg IV over 15 minutes
      2. Vitamin D Toxicity, Lymphoma, Myeloma or Granuloma
        1. Hydrocortisone 200 mg IV qd for 3 days
    5. Other measures
      1. Oral Phosphate (Neutra-Phos) 250 mg PO q6 hours
    6. Third line agents due to toxicity (avoid if possible)
      1. Plicamycin 10-25 mcg/kg/day IV over 6 hours x3 dose
        1. Cumulative liver, Kidney and platelet toxicity
        2. Bisphosphonates are preferred over Plicamycin
      2. Gallium Nitrate (Ganite)
        1. Dose: 100-200 mg/m2 IV over 24 hours for 5 days
        2. Significant renal and Bone Marrow toxicity
  • Prognosis
  1. Hypercalcemia of Malignancy suggests terminal stages
    1. Implies Life Expectancy of days to weeks