CC May 2015 Hypercalcemia

echoecho's version from 2015-05-06 15:17


Question Answer
List the 5 causes that influence serum calcium levels1. dietary intake 2. absorption from the GI tract 3. degree of renal reabsorption 4. relative rates of bone deposition and resportion 5. serum concentration of albumin and other binding proteins
Define severe hypercalcemia as to the serum levels in the blood?serum level of calcium > 14 mg/dL
Is severe hypercalcemia a metabolic emergency?yes
List the 5 symptoms in severe hypercalcemia?1. dehydration 2. malaise 3. nausea 4. mental status changes 5. cardiac conduction abnormalities
What has led to an increase in the dx of asymptomatic or mildly symptomatic hypercalcemia?the routine measurement of calcium levels in standard metabolic panels
What is serum calcium largely bound to?albumin or other proteins
What type of calcium does the standard calcium assays measure?total calcium levels
What type of calcium is biologically active?unbound (ionized) calcium
What serum levels have to be considered when interpreting serum calcium levels?serum protein levels
List 2 patient types in which the level of unbound (ionized) calcium should be measured directly?1. elevated albumin levels 2. paraproteinemia
What is the most common cause of hypercalcemia? What is the second most common cause of hypercalcemia?1. primary hypercalcemia 2. malignancy-associated hypercalcemia
What two simultaneous measurements should be done to distinguish between primary hyperalcemia and malignancy-associated hypercalcemia?1. calcium 2. PTH
What are the PTH levels in hyperparathyroidism?elevated or high-normal PTH
What are the PTH levels in malignancy-associated hypercalcemia?suppressed PTH level
List the most common cause of hyperparathyroidism?benign, hyperfunctioning adenoma
List the second most common cause of hyperparathyroidism?generalized parathyroid hyperplasia
List a rare cause of hyperparathyroidism?parathyroid carcinoma
*** What is the definitive treatment of primary hyperparathyroidism?surgery
*** When is surgery indicated in the hyperparathyroid patient? Give examples of 2 medical conditions where surgery is indicated?1. symptomatic patients 2. nephrolithiasis, fractures
*** List the 4 indications for surgery in ASYMPTOMATIC patients?1. calcium level more than 1.0 mg/dL above the upper limit of normal 2. age < 50 years 3. creatinine clearance of < 60 mL/min/1.73 m2 4. osteoporosis diagnosed either via a T-score of < 2.5 or a hx of fragility fracture
What 2 conditions are improved by surgery in patients with hypercalcemia and osteoprosis and osteopenia?1. bone density 2. fracture risk
If a patient does not undergo surgery, what 2 blood tests should be monitored annually? 1. calcium level 2. renal function
If a patient does not undergo surgery, what imaging study should be done every 1-2 years?BMD (bone mineral density)
What is the cause of the rare FHH (familial hypocalciuric hypercalcemia) that may mimic primary hyperparathyroidism??a mutation of the calcium sensing receptor
What is the pathophysiology of FHH (familial hypocalciuric hypercalcemia)?there is a higher "set point" at which calcium concentration suppresses PTH secretion and promotes calciuresis
Why should FHH (familial hypocalciuric hypercalcemia) be ruled out?to avoid subjecting patients to unnecessary surgery
What lab test and patient history fact would suggest FHH (familial hypocalcinuric hypercalcemia)?1. a 24 hour urine collection showing a calcium-to-creatinine clearance ratio of < 0.01 2. positive family hx of FHH (familial hypocalcinuric hypercalcemia)
What is the prognosis of malignancy-associated hypercalcemia?poor prognosis
List the 3 causes of hypercalcemia in malignancy-associated hypercalcemia?1. mediated by the secretion of parathyroid hormone-related peptide (PTHrP) 2. bone destruction by metastatic lesions 3. unregulated conversion of 25-OH vitamin D to the more biologically active 1,25 - (OH)2 vitamin D
Usually the malignancy is often clinically apparent in malignancy-associated hypercalcemia, however, in obscure cases, what levels can be measured to confirm the diagnosis?PTHrP (parathyroid hormone-related peptide)
List 2 drugs that can cause hypercalcemia (less common causes of hypercalcemia)?1. thiazides 2. lithium
What is the cause of milk-alkali syndrome? Historically, this was assoiated with what treatment? It may also be seen with what associated with prevention or treatment of osteoporosis?1. caused by ingestion of large amounts of calcium carbonate 2. historically associated with antacid treatment of ulcer disease 3. seen with excessive intake of calcium cabonate for prevention or treatment of osteoporosis
Vitamin D intoxication can occur when the 25-OH vitamin D exceeds _____ ng/dL?80 ng/dL
Which form of vitamin D is the most stable measure of vitamin D stores?25-OH form
Which form of vitamin D should be measure to evaluate suspected vitamin D disorders? 25-OH form
Which form of vitamin D can be triggered by lymphomas and granulomatous disease (such as sarcoidosis)?unregulated synthesis of 1,25-(OH)2 vitamin D can cause hypercalcemia
Define severe hypercalcemia?calcium > 14.0 mg/dL
Define moderate hypercalcemia?calcium 12.0 to 14.0 mg/dL
What two classes of hypercalcemia should be treated emergently if pt has symptoms?severe and moderate hypercalcemia
What is the most important initial treatment for severe and moderate hypercalcemia? Why?1. aggressive hydration 2. these calcium levels are associated with dehydration
What is the consensus for concurrent use of loop diuretics to promote calciuresis with aggressive hydration?there is a lack of rigorous evidence to do so, but some experts recommend it
IV bisphosphonates can be used to treat severe and moderate hypercalcemia, but what is the disadvantage of this treatment?the onset of action is 2-4 days
In the treatment of severe and moderate hypercalcemia, what medication is less effective than bisphosphonate therapy but may play a role in treatment in pts with contraindications to bisphosphonate therapy?Calcitonin