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Flashcards in calcium Deck (24):

Serum albumin levels affect________ calcium levels

TOTAL, but not, ionized calcium levels


To correct total calcium level for hypoalbuminemia......

Add about 1 mg/dL to serum Ca level for every 1 g/dL by which serum albumin is less than 4 g/dL Corrected [Ca] = Uncorrected [Ca] PLUS (4 – serum albumin)


what is normal value for total cerum Ca?

8.4 -10.2 mg/dL


what is normal value for ionized serum Ca?

4.2– 5.1 mg/dL


What is normal value for serum phos level?

2.5 – 4.5 mg/dL


3 facts on PTHrP (PTH related peptide)

- Acts on same receptors as PTH - Responsible for most cases of hypercalcemia of malignancy not due to bone metastases - Not measured in PTH assays; a specific assay for PTHrP is available


Calcitoni is stimulated and inhibited by what 2?

Stimulated by hypercalcemia Inhibited by hypocalcemia


What effects does calcitonin have on the body? useful in treating?

Lowers serum Ca by decreasing osteoclastic bone resorption Useful in treating: osteoporosis Paget’s disease of bone hypercalcemia


2 main causes for hypercalcemia?

Primary hyperparathyroidism* Malignancy*


3 causes of primary hyperparathyroidism?

Solitary adenoma Multiple endocrine neoplasia syndromes Lithium therapy (5-10% of treated patients)


3 causes of malignancy

1. Solid tumor with PTHrP production (squamous cell lung cancer, renal cancer) 2. Solid tumor with bone metastases (e.g., breast, prostate, colon) 3. Hematologic malignancies (multiple myeloma, lymphoma, leukemia)


vitamin D excess can also be a cause of hypercalcemia. What are 2 causes of vitamin D excess?

1. Vitamin D intoxication (50-100 x nl. intake) 2. Systemic causes of increased 1,25(OH)2D Sarcoidosis, Other granulomatous diseases (TB, fungus) B-cell lymphoma


signs and sx of hypercalcemia?

- Anorexia, nausea, vomiting - Constipation - Muscle weakness, fatigue - Depression, confusion, psychosis, lethargy;coma and death (severe cases) - Polyuria (decreased urinary concentrating ability) - Shortened QT interval, arrhythmias - Nephrolithiasis - Ectopic calcification in blood vessel walls, skin, soft tissues, renal parenchyma (nephrocalcinosis) ** often not seen if the level is below 12


rapid acting treatment of hypercalcemia?

- Forced diuresis with I.V. saline - I.V saline plus I.V. furosemide (?) - Calcitonin (I.V. or s.q.) - Dialysis--if in renal failure


slow acting treatment of hypercalcemia?

- Bisphosphonates [I.V. pamidronate (Aredia)] - Glucocorticoids (prednisone) Useful in cancer, vit. D intoxication, sarcoidosis


Most common cause of primary hyperparathyroidism is....

solitary adenoma hyperplasia comes in second


Most common sign and symptoms of hyperparathyroidism?

Most cases are asymptomatic with only mild hypercalcemia


laboratory findings with primary hyperparathyroidism?

Increased PTH Increased Ca Low serum phosphorus Increased serum Cl- and decreased HCO3 (hyperchloremic metabolic acidosis)


What is osteitis fibrosa cystica?

- a condition that is due to increased bone resorption due to hyperparathyroidism - will see punched out lesions in bones and loss of lamina dura around teeth


treatment of hyperparathyroidism?

1. surveillance (for those unwilling/dont qualify for surgery) 2. Sx


6 qualifications for surgery treatment of hyperparathyroidism?

1. Symptomatic hypercalcemia 2. Asymptomatic patients with serum Ca greater then 1mg/dL above ULN 3. Asymptomatic, age less then 50 4. Asymptomatic patients in whom surveillanceis not feasible 5. GFR less then 60 ml/min without other cause 6. bone density (T score less then -2.5)


5 causes of acute hypocalcemia?

1. Sepsis (hyperventilation; decrease albumin) 2. Hypoalbuminemia 3. Acute necrotizing pancreatitis 4. Rhabdomyolysis with or without acute renal failure 5. Extensive transfusion of citrated blood


4 causes of chronic hypocalcemia?

1. Secondary hyperparathyroidism (Chronic kidney disease (CKD) 2. Vitamin D deficiency (rickets, osteomalacia) 3. Hypoparathyroidism; pseudohypoparathyroidism 4. Hypomagnesemia (less then 1 mg)


4 signs and sx of hypocalcemia?

1. tetany 2. Mental changes: Irritability, depression, psychosis 3. Convulsions 4. Prolonged QT interval; arrythymias