Hypercalcemia and Hypophosphatemia Flashcards
What is normal serum calcium
8.5-10.5 mg/dl
What is normal ionized serum calcium
4.4-5.4 mg/dl
What protein has to be accounted for when referring to to total Calcium, does this protein cause any change in ionized Calcium
Albumin,no
What is the equation for corrected Calcium
(total measured serum calcium) + 0.8(4- measured serum albumin)
What is the normal serum albumin level
4 mg/dl
How does PTH affect bones,kidneys, and the gut
stimulates osteoclasts and cause bone breakdwon, increases reaborption of calcium in distal renal tubules, indirectly increases intestinal calcium absoption
What causes calcitonin to be increased
When ionzied calcium concentrations are high
What are ways hypercalcemia can occur
accelerated bone resporption, Excessive GI absorption, decreaed renal excretion of calcium
What are the ranges for hypercalcemia with respect to total serum calcium, ionized calcium
greater than 10.5, greater than 5.4
What is the disease that accounts for 90% of cases of hypercalcemia
primary and secondary hyperparathyroidism, malignancy
What is the cause of primary hyperparthyroidsim, secondary, tertiary
parathyroid adenoma, hyperplasia of the glands (adaptive disease in the setting of CKD), advanced renal failure
How high can calcium get due to malignancy
over 13 mg/dl
What are drugs that cause hypercalcemia
ergocalciferol, calcitrol, cholecalciferol, litihium, vitamin A, thiazide diuretics
How do thiazide diuretics cause hypercalcemia
increase renal tubular reabsorption of calcium in distal tubule, block Na reabsorption and increase calcium reabsorption, lowers urinary calcium excretion
What are moderate hypercalcemia total serum calcium levels, severe
12-14 mg/dl, greater than 14 mg/dl
What are symptoms of severe hypercalcemia
profound dehydration, renal failure, cardiovascular/neuromuscluar dysfunction, coma
What is the fluid that is used to treat severe hypercalcemia, why
09.% normal saline with loop diuretics to help increase calcium excretion, corrects volume depletion/increases renal excretion of calcium
Which treatment will cause rapid decrease in serum calcium
calcitonin
What treatment provides sustained effect in lowering calcium
Bisphosphonates
What is the last restort for hypercalcemia
Dialysis
What is the dose of normal saline in hypercalcemia
200-300 ml/hr, could be lower with older patients
What is the mechanism for calcitonin
Functionally antagonizes the PTH
What is the does for calcitonin, how can it be administered
4 IU/kg, IM/SC
T/F: The efficacy of calcitonin is limited to the first 72 hours and if responsive can repeat every 4-6 hours
False: The efficacy is limited to the 1st 48 hours and if responsive can be repeated every 6-12 hours from dose
T/F: The nasal formulation of Calcitonin does not work
True
What is the duration of bisphosphonates, when does the max effect take place
2-4 weeks, 2-4 days
What type of bisphosphonate is most commonly used in hypercalcemia, what is the dose
Zolendronic Acid, 4 mg IV over 15 minutes
When should bisphosphonates be avoided in a patient
if CrCl is less than 30ml/min
How often will bisphosphonates be administered in malignancy, what drug is administered as well and why
every 3 to 4 weeks, denosumab for refactory hypercalcemia
What is the role of glucocorticoids, what is one way they work
hypercalcemic presentation due to drugs or disease, decrease intestinal calcium
What drug can be used for chronic hypercalmia in hyperparathyroidism
sensipar (cinacalcet) and Parsabiv (etelcalcetide)
What is the starting dose for sensipar
30 mg daily with food
What is the dosing for parsabiv
5 mg IV bolus 3 times per week at the end of hemodialysis
T/F: When calcium is greater than or equal to 15 parental therapy is required
True
What creatine clearence is bad for bisphosphanates
30
What is a normal phosphorous range
2.5-4.5 mg/dl
What is the organ that affects phosphours levels the most
kidney
What inhibits phosphorous reabsorbtion
PTH and calcitrol
What are moderate and severe ranges of hypophosphatemia
1.5 mg/dl, less than or equal to 1 mg/dl
What the four key ways hypophosphatemia can occur
Redistribution of phosphate from extracellular fluid into cells, decreased intestinal absoprtion of phosphate, removal by renal replacement therapies
Where is phosphorous absorbed
From the intestines
What are the symptoms due to consequences of intracellular phosphorous depletion
Reduce oxygen tissue release, ATP levels fall and cell functions begin to fail
How low does phosphate usually get to cause symptoms
less than 1.0
Which oral phosphorous has the least amount of potassium
K phos neutral
T/F: A patient will receive IV phos therapy whether they are symptamatic or not
True
When should IV phos be switched to PO therapy
Once over 1.5
What is the IV dose for symptomatic patients with phosphorous greater than 1.5, less than 1.5
Max 30 mmol over 6 hours, max 80 mmol over 8-12 hours
When should phosphorous doses be lower, held off
Ca is around 10.5 to 12 cut the dose in half, renal dysfunction, if the Ca is more than 12 correct the calcium first due to a risk of calcification
When should potassium phosphate be given IV over sodium phosphate
When the patient’s potassium is less than 3.5 mEq/L
T/F: When PTH is present this stimulates the synethesis of calcitriol
True
What drug should be used to lower calcium quickly if the patient is symptomatic
Calcitonin
What drug should be used if the patient has longer term hypercalcemia due to malignancy, excessive bone resorption
Bisphosphonates
What is the mechanism of action for sensipar (cinclacet)
Decrease PTH by increasing sensitivity of calcium receptor on parathyroid gland
What is the biggest culprit for hypophosphatemia
continuous renal replacement therapies, dialysis
T/F: If the calcium is greater than 12 mg/dl half the dose of phosphorous
False: If calcium is greater than 12 mg/dl hold on phosphorous because calcification can occur, Half the does if the calcium is between 10.5 to 12
T/F: Monitor phosphorous every 6 hours
True
