Flashcards in WISEMD Hypercalcemia Deck (24)
Where is calcium absorbed? Where is it stored? Where is it excreted?
1) Small bowel
What regulates calcium and when it is secreted? What does this upregulate?
1) PTH regulates levels of calcium and is secreted by the parathyroid glands in response to low serum calcium levels
2) Increases intestinal and renal absorption of calcium, and increases bone breakdown
What enhances the effects of PTH? Where is this obtained from?
1) Vitamin D
2) Food, sunlight
What are the two most common causes of hypercalcemia (over 90%)?
2) Malignancy (Bone metastasis or produces PTH-related peptide, such as small cell carcinoma of the lung)
Is PTH elevated or decreased in primary hyperparathyroidism? What about calcium
1) Elevated PTH (10% have normal PTH)
2) Elevated calcium
What are the two causes of primary hyperparathyroidism?
1) Parathyroid adenoma (70%)
2) Parathyroid hyperplasia (Remaining amount)
How is primary hyperparathyroidism treated in symptomatic patients? In asymptomatic patients?
2) May need surgery depending on age, degree of osteoporosis, renal disease, or hypercalcemia
Which patients develop secondary hyperparathyroidism? What is it developed in response to? What does this response stimulate?
1) Seen in patents with severe renal disease or vitamin D deficiency
2) In response to low vitamin D levels, low serum calcium levels, or high serum phosphate levels
3) Stimulates parathyroid hyperplasia to increase PTH production
What are complications of secondary hyperparathyroidism if not corrected?
1) Renal osteodystrophy
2) Vascular calcifications
What is the treatment of secondary hyperparathyroidism if patients are not on dialysis? What about if they are on dialysis?
1) Vitamin D supplementation (Calcitriol)
2) Calcimimetics (Cinacalcet), which increases sensitivity of the calcium-sensing receptor (CaSR)
3) Phosphate binders
What is tertiary hyperparathyroidism?
Occurs after successful renal transplant when secondary hyperparathyroidism persists and becomes autonomous
When is parathyroidectomy indicated for tertiary hyperparathyroidism?
2) Severe hypercalcemia
3) Severe pruiritis
4) Severe renal osteodystrophy
5) Severe unexplained myopathy
What is the helpful pneumonic for remembering symptoms of hyperparathyroidism?
1) Painful bones
2) Renal stones
3) Abdominal groans
4) Psychiatric moans/overtones
What are the symptoms of hyperparathyroidism?
1) Osteoporosis or bone pain
2) Kidney or bladder stones
3) Abdominal pain, constipation
What other personal (not family) questions should be asked during a history of hyperparathyroidism that might explain the etiology?
1) Radiation exposure
2) Prior cancer
3) Renal disease
4) Vitamin D deficiency
5) Excessive calcium or vitamin D intake
6) Lithium or hydrochlorothiazide usage
Why is it important to ask questions about family history?
Multiple Endocrine Neoplasia Syndrome
1) MEN1 - Pituitary, parathyroid, pancreas
2) MEN2A - Medullary thyroid cancer, hyperparathyroidism, pheochromocytosis
Other very rare syndromes
What laboratory studies should be done for hyperparathyroidism?
1) Ionized calcium, calcium, phosphorus, chloride, and PTH levels (Sources of malignancy)
2) Electrolytes, BUN/Cr (Renal disease)
3) 24 hour urine calcium collection (Familial hypocalceuric hypercalcemia)
4) Vitamin D level (Deficiency)
5) Albumin (To calculate absolute calcium level, which is usually higher than the reported lab value)
Which lab studies will usually be elevated in patients with hyperparathyroidism? Which will be low?
1) Serum calcium, ionized calcium, PTH, chloride
What imaging should you begin with for hyperparathyroidism?
Neck/thyroid ultrasound to evaluate for parathyroid adenoma and possible concomitant thyroid nodule
What is another common imaging modality used after ultrasound? What does it evaluate for? What does delayed imaging on this scan show?
1) Sestamibi scan
2) Parathyroid adenoma, ectopic location, concomitant thyroid nodule
3) Delayed imaging increases sensitivity and specificity for adenoma
When is surgery indicated for hyperparathyroidism?
1) Symptomatic hyperparathyroidism
2) Asymptomatic hyperparathyroidism meeting NIH criteria
When can focused parathyroidectomy be accomplished?
1) If preoperative imaging confirms location
2) Intraoperative PTH measurements should decrease by 50% in 10 minutes
What are immediate post-operative complications of a parathyroidectomy?
1) Recurrent laryngeal nerve injury. Check for quality and strength of voice, and any hoarseness
2) Hypocalcemia presents with perioral numbness, numbness in the fingers or toes, and Chvostek's sign
3) Neck hematoma is life threatening because blood is trapped under the incision and the patient cannot breathe. Listen for inspiratory stridor