hypercalcemia Flashcards
initiate emergency management of hypercalcemia
- diagnose cause before imaging
- contrast pth-dep and pth-indep causes
- apply guidleines when referring for parathyroid Sx
- apply basic physiology of calcium and vitamin D metabl in management of post op hypocalcemia
.
Symptoms/signs of hypercalcemia
Bones - osteoporosis
Stones - Nephrolithiasis, polyuria
Groans - GI/abdo pain
Psychic overtones - neuropsych
Initial management of hypercalcemia is
FLUIDS
- Isotonic saline 300-500ml/Hr
- Saline + Loop Diuretic
How much Lasix do you need to add in state of hypercalcemia?
20-40 mg IV to treat volume overload
what is the physiologically active kind of calcium?
- ionized calcium
In a hypoalbumin state -
total calcium might be lower but ionized calcium might be ok
Correcting for low albumin states
- Every 10 mmol/L decrease in albumin increase total calcium by 0.2
Why is creatinine high in hypercalcemia?
- acute renal failure –> hypovolemia
To diagnose hypercalcemia always order
PTH
3 ways in which PTH acts
1 - bone resorption
2- increase hydroxylation of vitamin D in kidney
3- Renal Ca+2 resorption
which enzyme does PTH activate?
alpha-hydroxylase in the kidney
2 PTH-dependent causes of hypercalcemia
1- Primary hyperparathyroidism
2- Familial hypercalcemic hypocalciuria
PTH independent causes of hypercalcemia-
- Malignancy
- Drugs
- increased intake
- Granulomatous disease
- Pheo/thyrotox/addison’s
What type of drugs can cause hypercalcemia
- Thiazide diuretics
- Lithium
- Theophyline
Most common cause of hypercalcemia of malignancy
- Humoral - Paraneoplastic- (80%)
- Osteolytic (20%)
- 1,25 Vit D (<1%)
Causes of humoral/paraneoplastic PTH/PTHrP secretion
- Squamous cell cancer
- Renal cancer
- Ovarian cancer
Causes of osteolytic mets hypercalcemia
- Breast cancer
- MM
- Lymphoma
In PTH-dependent hypercalcemia why is phosphate low?
- PTH has an effect on kidneys - promotes renal excretion of phosphate
Treatment of hypercalcemia - 4 things to keep in mind!
1- volume expand
2- bisphosphonates - IV
3- gluc - in granulomatous disease prednisone
4- calcitonin- not useful
How do bisphosphonates work in context of hypercalcemia
- inhibit release of calcium from bone
- MUST be IV
- Pamidrone/zoledronic acid
When are glucorticoids useful for treating hypercalcemia?
- PTH-independent extra renal production of calcitriol -
- lymphoma
- sarcoidosis
- TB
Extra renal production of calcitriol can occur where?
- Lymphoma
- Sarcoidosis
- TB
- alpha hydroxylase active
3 things to keep in mind for emergency treatment of hypercalcemia
1) Fluids
2) Furosemide - loop diuretuc
DELAYED: bispho and gluc
Common causes of secondary Hyperparathyroidism (calcium is low, pth HIGH)
- Renal failure
- vit D deficiency
- Malabsorption- celiac
- PTH resistance
- hyperphosphatemia
