Calcium and Bone Disorders Flashcards
Normal PTH, high calcium suggests:
Primary hyperparathyroidism
or
Familial Hypocalciuric Hypercalcemia
Name 5 causes of PTH independent hypercalcemia
Malignancy Granulomatous disease Vitamin A toxicity VItamin D toxicity Milk alkali syndrome
Main defense against hypercalcemia
PTH suppression
Phosphorus level in primary hyperparathyroidism
normal-low b/c increased PTH mediated renal excretion
Best approach of treatment for primary hyperparathyroidism
Parathyroidectomy
Describe the expected levels in primary hyperparathyroidism:
Ca:
PTH:
Phosphorus:
Ca: increased
PTH: increased
Phosphorus: low-normal
If patient’s serum calcium is not too high, has osteoporosis and refuses to have parathyroidectomy to treat his primary hyperparathyroidism, you should treat with ____
bisphosphonate
If patient’s serum calcium is very high and refuses to have parathyroidectomy to treat his primary hyperparathyroidism, you should treat with ____
Cinacalcet = calcimiertric
Mimics calcium → binds Ca sensing receptors (CaSR) on parathyroid tissue → decrease PTH secretion → decrease Ca level
Cinacalcet (calcimiertric) treats all of the following except:
A. Severe secondary hyperparathyroidism
B. Hypercalcemia due to parathyroid carcinoma
C. Familial Hypocalciuric Hypercalcemia
D. Primary hyperparathyroidism
C
Describe the expected levels in Familial Hypocalciuric Hypercalcemia
Ca:
PTH:
Urinary Ca:
Ca: mildly elevated
PTH: normal - slightly elevated
Urinary Ca: VERY low
Distinguishes FHH from primary hyperparathyroidism
Name the disorder:
Inactivating mutation in gene of calcium-sensing receptor
Familial Hypocalciuric Hypercalcemia
Which of the following is NOT a symptom of hypercalcemia? A. Fatigue B. Tetany C. Bradycardia D. HTN E. Polyuria
B. sign of HYPOcalcemia
Describe the expected levels in Milk Alkali Syndrome:
Ca:
PTH:
Ca: increased
PTH: low
Normal PTH-rP, 25 OHD, 1,25 (OH)2D, Vitamin A, SPEP to rule out other PTH independent causes
Acute therapy of PTH independent hypercalcemia
Fluids to induce natriuresis
Intermediate therapy of PTH independent hypercalcemia
IV bisphosphnates:
Zoledronic acid
Pamidronate
Describe the expected levels in PTH independent hypercalcemia:
Ca:
PTH:
Ca: high
PTH: low
Trying to unsuccessfully correct calcium b/c another process is driving calcium up
Hypercalcemia of malignancy w/ PTHrP seen in (2)
Lung
Renal cell
Hypercalcemia of malignancy w/ 1,25 (OH)2 vitamin D seen in (2)
Lymphoma
Leukemia
Most common cause of hypercalcemia in hospitalized patients
Hypercalcemia of malignancy
Describe the expected levels in hypoparathyroidism: PTH: Ca: Urine Ca: Phosphorus:
PTH: Low (Normal: should be high in low Ca)
Ca: Low
Urine Ca: High (PTH normally promotes renal calcium reabsorption)
Phosphorus: High (PTH normally promotes renal P excretion)
Treatment of hypoparathyroidism
Calcium
Calcitriol (1,25 OH2D)
Which of the following is NOT a symptom of hypocalcemia? A. Parasthesia B. Tetany C. Confusion/fatigue/depression D. QT shortening E. Seizures
D. QT prolongation
Inflating a blood pressure cuff to 20 mmHg above systolic blood pressure for 3 minutes inducing the Carpopedal spasm
Trousseau’s sign
Sign of hypocalcemia
Elicited by tapping facial nerve → contraction of (contralateral/ipsilateral) facial muscles
Ipsilateral
Chvostek’s sign
All of the following are treatments for hypoparathyroidism EXCEPT:
A. Calcium
B. Vitamin 25(OH)2D
C. Human recombinant PTH
B. Vitamin 1,25(OH)2D: Must be active form b/c PTH not available to activate.
A. IV if tetany. Oral otherwise
C. Just approved. Not ideal.
When you see hypocalcemia, check ___ to evaluate for cause.
PTH
Low calcium, high PTH suggests (4)
Poor calcium intake
Vitamin D deficiency
PTH resistance: pseudohypoparathyroidism
Vitamin D resistance
Describe the expected lab values for Vitamin D deficiency: Ca: PO4: PTH: 25(OH)D: 1,25 (OH)2D:
Ca: low PO4: low b/c PO4 b/c need vit D to absorb PTH: high 25(OH)D: low 1,25 (OH)2D: low/normal
Describe the expected lab values for PTH resistance (pseudohypoparathyroidism): Ca: PO4: PTH: 25(OH)D: 1,25 (OH)2D:
Ca: low PO4: high PTH: high 25(OH)D: normal 1,25 (OH)2D: low
Describe the expected lab values for Vitamin D resistance: Ca: PO4: PTH: 25(OH)D: 1,25 (OH)2D:
Ca: low PO4: low PTH: high 25(OH)D: normal/low 1,25 (OH)2D: high b/c try to make more vit D to overcome resistance due to defective receptor
T/F: Treatment for Vitamin D deficiency includes calcitriol, the activated form.
False. Treat with Vitamin D2 or D3.
o No need for activated form (calcitriol) since patient can make PTH
Which disorder? Ca: low PO4: low PTH: high 25(OH)D: normal/low 1,25 (OH)2D: high
Vitamin D resistance
Which disorder? Ca: low PO4: high PTH: high 25(OH)D: normal 1,25 (OH)2D: low
PTH resistance (pseudohypoparathyroidism)
Ca: low PO4: low PTH: high 25(OH)D: low 1,25 (OH)2D: low/normal
Vitamin D deficiency
