II. Causes: General
- Most common causes of Hypercalcemia
- Malignancy
- Primary Hyperparathyroidism
- Malignancy
- See Hypercalcemia of Malignancy (mediated by PTH-Related peptide)
- Presents with rapid onset, low PTH Levels and weight loss, Night Sweats
- Breast Cancer with bone metastases
- Squamous Cell Lung Cancer
- Head and Neck squamous cell cancer
- Renal Cell Cancer
- Esophageal Cancer
- Skin Cancer
- Hematologic
- Paget's Disease of Bone
- Medications
- Thiazide Diuretics
- Lithium
- Vitamin A Toxicity
- Vitamin D Toxicity (e.g. 25-Hydroxyvitamin D2)
- Milk Alkali Syndrome
- Theophylline
- Synthetic PTH (Teriparatide, Abaloparatide)
-
Hyperparathyroidism (PTH Dependent Hyperparathyroidism)
- Primary Hyperparathyroidism (most common cause)
- Multiple Endocrine Neoplasia (type 1 or 2A)
- Familial Hypocalciuric Hypercalcemia
- Lithium treatment
- Chronic Kidney Disease (Renal Osteodystrophy)
- Hyperparathyroidism - Jaw Tumor Syndrome
- Endocrine
- Other causes
- Familial Hypocalciuric Hypercalcemia
- Prolonged immobilization
- Granulomatous disease (Sarcoidosis, Tuberculosis, Histoplasmosis, Coccidioidomycosis)
- Williams Syndrome
- Jansen Disease (metaphyseal chondrodysplasia)
III. Findings: Symptoms and Signs
- Often asymptomatic
- Symptoms and Signs are related to Serum Calcium Levels
- Calcium > 11.5 mg/dl (2.9 mmol/L)
- Symptom onset
- Calcium > 13 mg/dl (3.2 mmol/L)
- Nephrocalcinosis
- Acute Renal Failure
- Calcium >14 mg/dl (3.5 mmol/L)
- Severe Hypercalcemia (or Parathyroid crisis)
- Calcium > 11.5 mg/dl (2.9 mmol/L)
- Cardiovascular
- Gastrointestinal
- Renal
- Polydipsia
- Polyuria
- Renal Colic or Flank Pain
- Renal Failure
- Neurologic
- Anxiety
- Confusion, Delirium
- Decreased Concentration
- Memory Loss
- Headache
- Fatigue
- Lethargy
- Weakness
- Psychiatric
- Anxiety
- Depressed Mood
- Emotional lability
- Musculoskeletal
- Bone pain
- Arthralgias
- Myalgias
- Pathologic Fractures
- Skin
- Pruritus (Metastatic calcification of skin)
IV. Complications: Stones, Bones, Moans, Psychic Groans
- Renal ("Stones")
- Nephrolithiasis (Calcium Oxalate)
- Nephrocalcinosis
- Metastatic calcification renal tubules
- Polyuria from loss of urine concentrating function
- Musculoskeletal ("Bones")
- Osteitis fibrosa cystica (Late finding)
- Bone cysts from subperiosteal bone resorption
- "Brown tumor" in jaw
- Pseudogout
- Calcium pyrophosphate - Positively birefringent
- Osteoporosis
- Osteitis fibrosa cystica (Late finding)
- Gastrointestinal ("Abdominal Moans")
- Peptic Ulcer Disease
- Acute Pancreatitis
- Calcium activates phospholipases
- Constipation
- Most common gastrointestinal symptom
- Neuropsychiatric ("Psychic groans")
- Altered Level of Consciousness or Delirium
- Decreased concentration and memory
- Personality change
- Psychosis
- Major Depression
- Eye
- Band Keratopathy (Corneal calcification)
- Metastatic calcification in eye limbus
- Band Keratopathy (Corneal calcification)
- Cardiovascular
- Cardiac Arrhythmia
- Diastolic Dysfunction
- Hypertension
- Hypercalcemia Vasoconstricts vessels
V. Imaging
- Calcified soft tissues
VI. Labs: Serum Calcium
- Total Serum Calcium increased
- Hypercalcemia: Total Serum Calcium > 10.5 mg/dl
- Severe Hypercalcemia (Hypercalcemic Crisis): Serum Calcium >14 mg/dl (>3.50 mmol/L)
- Confirmatory
- Ionized Calcium >5.6 mg/dl or
- Corrected Serum Calcium increased (corrected for Serum Albumin)
VII. Labs: Hypercalcemia Evaluation
- First-line
- Parathyroid Hormone
- 25-Hydroxyvitamin D
- Serum Magnesium
- Serum Creatinine
- Second-line: PTH level normal or high (PTH-dependent Hypercalcemia)
- Urine Calcium to Creatinine Ratio
- Decreased <0.01 in Familial Hypocalciuric Hypercalcemia
- Increased >0.01 in Primary Hyperparathyroidism, Hypercalcemia or Malignancy, MEN I
- Urine Calcium to Creatinine Ratio
- Second-line: PTH level <20 pg/ml (PTH-independent Hypercalcemia)
- Parathyroid Hormone-related Peptide (PTHrp) increased
- Hypercalcemia of Malignancy
- Consider broad evaluation for malignancy
- Complete Blood Count
- Liver Function Tests
- Chest XRay
- Chest CT and Abdominal CT
- Protein electrophoresis (SPEP and UPEP)
- Bone Scan
- Mammogram
- 1,25 Dihydroxyvitamin D increased
- Lymphoma
- Granuloma (e.g. Sarcoidosis)
- 25-Hydroxyvitamin D (Calcitriol) increased
- Parathyroid Hormone-related Peptide (PTHrp) increased
VIII. Diagnostics: Electrocardiogram
- Short QT Interval
- Prolonged PR Interval
- Wide QRS Complex
- Bradycardia
IX. Evaluation
-
General
- Primary Hyperparathyroidism and Hypercalcemia of Malignancy: 90% of cases
- Step 1: Confirm Hypercalcemia present (see labs above)
- Confirm Hypercalcemia with Ionized Calcium >5.6 mg/dl or Corrected Serum Calcium >10.5 mg/dl
- Immediate management for symptomatic or severe Hypercalcemia (Serum Calcium >14 mg/dl)
- See protocol below
- Step 2: Obtain history for potential causes
- See causes above
- Perform history (including diet, medications) and exam
- Consider Renal Osteodystrophy
- Eliminate potential causative medications (Thiazide Diuretics, Lithium)
- Step 3: Obtain intact Parathyroid Hormone (PTH) Level
- PTH low: Go to Step 4
- PTH normal or high (PTH-Dependent Hypercalcemia)
- Labs
- Urine Calcium to Creatinine Ratio (24 hour Urine Calcium and Urine Creatinine)
- Serum Creatinine
- Bone Mineral Density
- 25-Hydroxyvitamin D
- Urine Calcium to Creatinine Ratio <0.01
- Urine Calcium to Creatinine Ratio normal or high
- Causes
- Primary Hyperparathyroidism
- Recovery from Acute Tubular Necrosis
- Lithium
- Multiple Endocrine Neoplasia Type I (MEN I)
- Parathyroid carcinoma (severe Hypercalcemia and very high PTH)
- Approach
- Consult Endocrinology
- Exclude Multiple Endocrine Neoplasia Type I (MEN I)
- Manage Primary Hyperparathyroidism
- Medical management of Primary Hyperparathyroidism
- Parathyroidectomy if symptomatic, age <50, complications (e.g. renal)
- Causes
- Labs
- Step 4: PTH-Independent Hypercalcemia
- Assess for malignancy and endocrinopathy
- Careful history and examination for tumor
- Initial Labs
- Parathyroid Hormone-related Peptide (PTHrp)
- Increased in solid tumors (see Hypercalcemia of Malignancy)
- Consider broad evaluation for malignancy
- Complete Blood Count
- Liver Function Tests
- Chest XRay
- Chest CT and Abdominal CT
- Protein electrophoresis (SPEP and UPEP)
- Bone Scan
- Mammogram
- 1,25-dihydroxyvitamin D (Calcitriol) increased
- Obtain chest imaging (Chest XRay or Chest CT)
- Causes
- Lymphoma
- Granulomatous Disease (Sarcoidosis, Tuberculosis, Histoplasmosis, Coccidioidomycosis)
- 25-Hydroxyvitamin D Level increased
- Parathyroid Hormone-related Peptide (PTHrp)
- Other Labs to consider
- Alkaline Phosphatase: Increased with bone lysis
- Consider bone scan
- Protein electrophoresis (SPEP and UPEP)
- Monoclonal peak in Multiple Myeloma
- Endocrine Labs
- Thyroid Stimulating Hormone (Hyperthyroidism)
- Corticotropin Stimulation Test (Addison's Disease)
- Insulin-like Growth Factor 1 (Acromegaly)
- Alkaline Phosphatase: Increased with bone lysis
- Reconsider medication causes of low PTH
X. Management
- Identify and treat underlying cause
- Mild Hypercalcemia (Serum Calcium <12 mg/dl)
- Adequate Hydration (>2 Liters per day)
- Maximize mobility
- Diuretics if symptomatic
- Furosemide (Lasix) 40-160 mg/day
- Severe Hypercalcemia or Hypercalcemic Crisis (Serum Calcium >14 mg/dl, >3.50 mmol/L)
- Consider also in moderate symptomatic Hypercalcemia
- Normal Saline 2 to 4 Liters/day for 1-3 days
- Adjust to obtain 200 ml Urine Output per hour
- Exercise caution in Congestive Heart Failure
- Anticipate 1-3 mg/dl drop in Serum Calcium
- Additional measures if refractory after hydration
- Furosemide (Lasix) 10-20 mg every 1-2 hours as needed
- Most effective agent in Calcium elimination
- Calcitonin 4-8 IU/kg IM or SQ every 6 hours for 24 hours (up to 48 hours)
- Rapid onset, but weakest of the agents (do not use as monotherapy)
- Furosemide (Lasix) 10-20 mg every 1-2 hours as needed
- Agents with specific indications
- Malignancy: Bisphosphonates
- Zoledronic acid (Zometa) 4 mg IV over 15 minutes
- Pamidronate (Aredia) 60-90 mg IV over 4 hours
- Vitamin D Toxicity, Lymphoma, Myeloma or Granuloma
- Hydrocortisone 200 mg IV qd for 3 days
- Malignancy: Bisphosphonates
- Other measures
- Oral Phosphate (Neutra-Phos) 250 mg PO q6 hours
- Denosumab
- Third line agents due to toxicity (avoid if possible)
- Plicamycin 10-25 mcg/kg/day IV over 6 hours x3 dose
- Cumulative liver, Kidney and Platelet toxicity
- Bisphosphonates are preferred over Plicamycin
- Gallium Nitrate (Ganite)
- Dose: 100-200 mg/m2 IV over 24 hours for 5 days
- Significant renal and Bone Marrow toxicity
- Plicamycin 10-25 mcg/kg/day IV over 6 hours x3 dose
- Refractory Cases
XI. Prognosis
-
Hypercalcemia of Malignancy suggests terminal stages
- Implies Life Expectancy of days to weeks
XII. References
- Gibbs in Marx (2002) Rosen's Emergency Med, p. 1734-6
- Spiegel in Goldman (2000) Cecil Medicine, p. 1400-2
- Carroll (2003) Am Fam Physician 67(9):1959-66 [PubMed]
- Michels (2013) in Am Fam Physician 88(4): 249-57 [PubMed]
- Minisola (2015) BMJ 350: h2723 [PubMed]
- Sell (2022) Am Fam Physician 105(3): 289-98 [PubMed]
- Suliburk (2007) Oncologist 12(6): 644-53 [PubMed]
- Ziegler (2001) J Am Soc Nephrol 12 Suppl 17:S3-9 [PubMed]