Hypercalcemia crisis (serum calcium > 2.9 mmol/L) can lead to coma and acute renal failure. ^[1] [2]

Consider Hyperparathyroidism ^{[3] [4]}: “Stones, bones, groans, psychiatric overtones.”

• History of kidney stones.
• Bone pain.
• Gastrointestinal Symptoms (constipation, nausea, vomiting, anorexia).
• Confusion, depression, memory loss.

Parathyroid hormone (PTH) maintains serum calcium homeostasis ^[4].

Normal serum calcium (corrected) = 2.1-2.6 mmol/L ^[3].

Figure 1. Parathyroid Gland Schematic (https://commons.wikimedia.org/wiki/File:Illu_thyroid_parathyroid.jpg)

Primary Hyperparathyroidism ^{[2] [4] [5] [6]}

• Inappropriate secretion of PTH by the parathyroid gland.
• Most common cause of hypercalcaemia.
• Peak age 50-60, male to female ratio 3.5:1.
• Most common in postmenopausal women.
• Risk Factors:
  • Prolonged use of furosemide.
  • Hx of neck radiation therapy.
  • Lithium therapy.
• Causes:
  • Adenoma – 85%
  • Carcinoma – <1%

Secondary Hyperparathyroidism

• Parathyroid hyperplasia resulting from continual PTH production from low calcium (and high phosphorus).
• Causes:
  • Vitamin D deficiency ~ 50%
  • Chronic kidney disease (CKD) ~ 15%
  • Reduced intestinal absorption (IBD, celiac, surgery)

In the emergency department, identification of severe hypercalcaemia is key.

Figure 2 provides a simplified overview for diagnosis of hyperparathyroidism. Note, Definitive hyperparathyroidism diagnosis not usually established in the ED.

Figure 2. Simplified diagnostic approach for Hyperparathyroidism [2] [3] [4] [7].

Table 1. Common findings for primary and secondary hyperparathyroidism [2] [4] [7] [8]

Treat hypercalcemia ^[3]:

• Increase Ca excretion:
  • Normal Saline IV Fluids at 200-300mL/hr to promote renal elimination of Ca.
  • Loop diuretics, decrease resorption of Ca.
  • Hydrocortisone 100mg QID, inhibits effect of Vit D, decrease intestinal absorption of Ca, increase renal elimination of Ca, inhibit osteoclast-activating factor.
• Reduce Ca release:
  • Calcitonin lowers Ca within 24-48 hours.
  • Bisphosphonates (pamidronate 90mg IV), potent inhibitors of osteoclast activity.
• Others:
  • Stop taking drugs that increase Ca, i.e. thiazides, vitamin A and D, and Ca supplements.
  • Correct potassium and magnesium level.

The definitive treatment for primary hyperparathyroidism is surgery.

• Severe hypercalcemia.
• Renal failure.
• Altered mental status.
• Severe dehydration.
• Cardiac complications.

Acute presentation cannot be managed at the current facility.

• Clinically unstable.
• Severe hypercalcemia.

• Clinically stable.
• Follow up possible with Family physician for confirmation or endocrinology.

1. Dehydration.pdf (bcemergencynetwork.ca)

   Parathyroid Website: Parathyroid Glands, Hyperparathyroidism, High Calcium and Parathyroid Surgery by Expert Parathyroid Surgeons.

   Hypercalcaemia: https://youtu.be/R9vSW_SqYXU

   
   

1. Wallace. Lecture: Parathyroid Basics and Clinical Scenarios in Parathyroid Disease. MEDD 412 2023. Vancouver, British Columbia, Canada: University of British Columbia Medical Program.

   
   

2. Pokhrel et al. Primary Hyperparathyroidism. Retrieved from In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing 2022. https://www.ncbi.nlm.nih.gov/books/NBK441895/

   
   

3. Nickson. Hypercalcaemia. Retrieved from Life in the Fastlane 2020. https://litfl.com/hypercalcaemia/

   
   

4. Taneigra. Hyperparathyroidism. American Family Physician 2004, 69(2), 333-339.

   
   

5. Jamal & Miller. Secondary and Tertiary Hyperparathyroidism. Journal of Clinical Densitometry 2013, 64-68. doi:0.1016/j.jocd.2012.11.012

   
   

6. Melck. Lecture: Endocrine Surgery – Thyroid and Parathyroid. MEDD 412 2023. Vancouver, British Columbia, Canada: University of British Columbia Medical Program.

   
   

7. Muppidi et al. Secondary Hyperparathyroidism. Retrieved from StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing 2023. https://www.ncbi.nlm.nih.gov/books/NBK557822/

   
   

8. Norman Parathyroid Center. Secondary Hyperparathyroidism: Disease of the Parathyroid Glands Caused by Something Else 2023. Retrieved from Parathyroid.com: https://www.parathyroid.com/secondary-hyperparathyroidism.htm