Calcium disorders

Question 1

definition

Answer 1

• abnormal serum calcium determined by elevated IONIZED (free) calcium
• always correct for albumin

Question 2

physiology

Answer 2

• derived from diet, bone turnover, and reabsorption by kindeys
• if ca low, stimulates PTH to increase Ca release from bone, increase renal reabsorption of Ca

Question 3

Hypercalcemia etiology

Answer 3

• most commonly primary hyperparathyroidism (benign adenoma)
• peaks age 70-79
• primary hyperparathyroidism
• medications: lithium, thiazides, excess vit D, Ca, or vit A
• malignancy (solid organ tumors or lymphoma via incrased 1,25OH vit d production)
• granulomatous disese: sarcoid, TB (increase Vit D w/in granuloma)

renal disease:

early: 2/2 HPT, decresed vit D conversion at kidney, increased PTH, pt often w/ low Ca
late: 3/3 HPT, over time, stimulated parathyroid gland leads to autonomous PTH production

other: thyrotoxicosis, immobilization (esp w/ pagets), milk-alkali syndrome, FHH

Question 4

signs/symptoms

Answer 4

• dehydration (increased Ca excretion–> polyuria)
• nephrolithiasis
• CKD
• constipation, bone pain, mood changes

Question 5

labs

Answer 5

obtain PTH and Vit D on all patients

suppressed PTH
-malignancy or excess Vit D ingestion/production

normal/elevated PTH

• primary or tertiary HPT
• FHH, order 24h urinary calcium

Question 6

management hypercalcemia

Answer 6

Primary HPT
-parathyroidectomy and surgery referral

teritary
-nephro referral

malignancy
-oncology referral