2-6: 5/25: Hypercalcemia & Hyperparathyroidism

Front 1

When would you calculate a corrected calcium?

What is the equation?

Back 1

Total calcium varies with serum albumin. If albumin levels are abnormal, calculate corrected calcium, or just use ionized calcium level.

Total serum calcium + (4.0-serum albumin) x 0.8

Front 2

Lab results for hypercalcemia.

Back 2

Normal is 9-10.5

Mild hypercal: <12

Anything above 14 is a medical emergency

Front 3

Causes of TRUE hypercalcemia

Back 3

Accel bone resorption via PTH, PTHRP, 1,25 OHD, cytokines

Excessive GI absorption of Ca

Inc'd reabsorption of Ca in distal renal tubule and/or diminished capacity of kidneys to excrete calcium

Front 4

Causes of PSEUDOhypercalcemia

Back 4

Inc in serum albumin due to dehydration, volume contraction or hemoconcentration during venipuncture

Abnormal protein binding in multiple myeloma
Waldenstrom's macroglobulinemia

Front 5

Two major causes of true hypercalcemia.

Back 5

Primary hyperparathyroidism
Malginancy

Front 6

Primary Hyperparathyroidism:
Definition
Causes
Pathophysiology by Cause

Back 6

Condition in which more PTH is produced by the parathyroids than is needed

Causes:
Benign adenoma (80-85%) (PTH Cells lose sensitivity to level of Ca2+)

Hyperplasia (15-20%): setpoint for calcium is unchanged; increase in number of cells results in hypercalcemia

Cancer <0.5% (RARE)

Front 7

Effect of lithium on calcium levels.

Back 7

Stimulates PTH secretion
Increased renal calcium absorption

Front 8

Primary Hyperparathyroidism:
Clinical Manifestions

Back 8

Skeletal abnormalities
Renal Diabetes Insipidus
Kidney Stones
Muscle, CNS, GI dysfn

Bones
Stones
Moans
Groans

Front 9

Laboratory findings in Primary Hyperparathyroidism

Back 9

-Serum PO4 often low normal
-Serum 1,25 OHD either normal or increased
-Urine Ca increased

Front 10

Familial Hypocalciuric Hypercalcemia

What ions are affected?

Back 10

Autosomal Dominant
Appearance before 10 years of age
Usually asyx

Chemically similar to primary hyperpara except for dec'd Ca and Mg excretion and increase in serum Mg

Mutation of Ca-sensint receptor of Parathyroids and disturbed Ca-sensing receptors to kidneys

Front 11

Indications for surgery for patients with primary hyperparathyroidism.

Back 11

Serum Ca consistently >1mg/dl above normal

Typical para/ca related syx

Kidney stones

Reduced creat clearance

OSTEOPOROSIS

Age <50 years

Front 12

Sestamibi technetium scan

Back 12

generally for localization of a parathyroid lesion in proximity to the thyroid gland

Front 13

Differential Diagnosis for Hypercalcemia

Back 13

PTH related (primary hyperpara)

Malignancy Related (humoral hypercal, mets, E2 therapy, ectopic 1,25-OHD (LYMPHOMA producing PTH-RP), ectopic PTH)

Vit D related (intoxication, sarcoidosis, TB, granulomatous dz)

Front 14

Malignancy Associated Hypercalcemia:
Causes

Back 14

Humoral, PTHRP related (80%)
Local osteolytic mets (20%)
ectopic 1,25-OHD (LYMPHOMA producing PTH-RP)
ectopic PTH (RARE)

Front 15

Granulomatous Hypercalcemia:
Causes

Back 15

Abnormal 1,25-OHD production due to
Tb
Sarcoidosis
Coccidiomycosis
Histo
Leprosy

Front 16

What is tertiary hyperparathyroidism?

Back 16

Development of autonomous parathyroid lesion(s) in patients with longstanding secondary hyperparathyroidism

Front 17

Hypercalcemia:
Management

Back 17

Discontinue intake of Ca, Vit D, thiazides, Li
Begin hydration to expand hydrovascular volume (IV saline)--salt will drag out calcium

Loop Diuretic: furosemide

Glucocorticoid therapy IV

Low calcium diet

Front 18

Zoledronic acid:
Class
Mechanism

Back 18

Bisphosphonate

Inhibits bone resorption by inhibiting osteoclasts (takes 2-3 days, lasts for weeks)

Front 19

Salmon Calcitonin:
Mechanism
Use

Back 19

Antiosteoclastic effect
Calciuric effect

Use until bisphosphonate starts working in hypercalcemic pts