Clin Med - Parathyroid (Carlozzi)

Question 1

Identify the symptoms consistent with hyperparathyroidism

Answer 1

• Stones: renal stones, polyuria, polydipsia, uremia
• Bones: osteitis fibrosa, radiologic osteoporosis, osteomalacia - MC phalanges or distal clavicles
• Abdominal Groans: constipation, nausea, vomiting, peptic ulcer, pancreatitis
• Psychic Moans: lethargy, fatigue, depression, memory loss, psychosis, personality change, confusion, coma
• Short QT interval

Question 2

Outline the medical therapy of primary hyperparathyroidism

Answer 2

• Usually managed surgically
• Observation reserved for patients with comorbid conditions who can’t tolerate surgery or for very elderly patients who may die of another cause
• In postmenopausal women: estrogen supplements and alendronate may help with bone density
• Those who go through parathyroidectomy should be monitored with metabolic panels and assessment of bone mass

Question 3

Explain the role of using a parathyroid hormone level to determine the cause of hypercalcemia

Answer 3

•Intact PTH can differentiate hyperparathyroidism induced hypercalcemia from other forms of hypercalcemia

• if PTH high, then cause for hypercalcemia is hyperparathyroidism
• if PTH suppressed, then other etiologies must be investigated

Question 4

What does the term “hungry bone syndrome” mean?

Answer 4

marked hypocalcemia and hypophosphatemia can occur in those with long-standing hyperparathyroidism and extensive bone resorption

Question 5

Explain the manifestations of hungry bone syndrome

Answer 5

• Rebound uptake of calcium and phosphorus by bones that have been starved from hyperparathyroidism results in postop hypocalcemia
• usually seen in pts with elevated preoperative alk phos
• Will have low phosphorus (high in surgical hypoparathyroidism), elevated PTH, and low mg
• can be associated with severe and diffuse bone pain

Question 6

What is the treatment of hungry bone syndrome?

Answer 6

If pt is symptomatic, use IV calcium.

Question 7

Outline the monitoring parameters for post-surgical parathyroidectomy patient.

Answer 7

• Serum calcium monitored several weeks after surgery until levels stabilized
• Calcium/PTH checked 6 months post-op to exclude persistent hyperparathyroidism
• If treated with oral calcium/vitamin D, IV calcium used for severe/symptomatic hypocalcemia

Question 8

Parathyroidectomy 1+ gland versus 4-gland removal.

Answer 8

When 1+ parathyroid gland identified/preserved - parathyroid hormone level usually return to normal and 4-gland removal can lead to permanent hypoparathyroidism

Question 9

Identify the symptoms consistent with hypoparathyroidism

Answer 9

• Paresthesia
• Hyperirritability
• Fatigue
• Anxiety
• Mood swings/personality disturbances
• Seizures
• Hoarseness
• Wheezing/dyspnea
• Muscle cramps, diaphoresis, biliary colic
• Hypomagnesemia, hypokalemia, alkalosis - worsen signs/sx of hypocalcemia

Question 10

Describe the iatrogenic cause of hypoparathyroidism

Answer 10

• Excision of all parathyroid glands through surgery in treatment of thyroid, laryngeal or other neck malignancy
• Repeated neck explorations for primary hyperparathyroidism caused by parathyroid adenoma may also cause it
• Extensive irradiation of face, neck mediastinum - can cause destruction of all 4 parathyroid glands

Question 11

Lab workup of hypoparathyroidism

-PTH hormone

Answer 11

•Low concentration with concomitant low calcium level in primary hypoparathyroidism

• Would be elevated as result of resistance to PTH from mutations in PTH receptor system: if pseudohypoparathyroidism
• Low, with high calcium levels in secondary hypoparathyroidism

Question 12

Lab workup of hypoparathyroidism

-calcium

Answer 12

•Total calcium level cannot be interpreted without protein/albumin levels

• Hypoalbuminemia can cause low overall calcium levels: for every 1mg/dL drop in serum albumin below 4.0, add 0.8mg/dL to the calcium
• Alkalosis causes ionized calcium to bind to albumin more strongly: causes decrease in ionized calcium

Question 13

Lab workup of hypoparathyroidism

-vitamin D

Answer 13

Important to exclude vitamin D deficiency as cause of hypocalcemia

Question 14

Lab workup of hypoparathyroidism

-serum magnesium

Answer 14

Hypomagnesemia may cause PTH deficiency and hypocalcemia: exclude in patient with primary hypoparathyroidism

Question 15

Lab workup of hypoparathyroidism

-serum phosphorus

Answer 15

In absence of PTH, phosphorus levels in blood may rise

Question 16

Outline the monitoring parameters for patient with chronic hypocalcemia

Answer 16

• Serum calcium, phosphorus, creatinine: weekly-monthly during initial phase and twice yearly after treatment stabilization
• F/u evaluations: every 1-2 weeks during initial phase and every 3-6 months after treatment stabilization
• Urinary calcium: twice yearly
• Ophthalmoscopic exam: yearly