- Increased calcium is often caused by malignancy.
- Calcium regulation is carried by PTH (increases serum calcium, decreases serum phosphate, increases bone resorption) , calcitonin (decreases calcium, decreases bone resorption) and active vitamin D (increases calcium and phosphate, increases bone resorption). Increases bone resorption = pulls calcium out of the bone, into the blood.
- Hyperparathyroid conditions affect calcium levels
- Stones (increased calcium increases risk of kidney stones), bones (bone pain, increased resorption from bones), groans (abdominal pain, increased risk of pancreatitis), thrones (polyuria, due to the effects of vasopressin, but increase in ca even more) and psychiatric overtones (depression, confusion, agitation, increase in calcium causes CNS depression, ECG changes: Osborn wave, shortened QT, AV block).
- 40% of calcium is bound to albumin, every 1g/dl decrease in albumin from 4, increase calcium by 0.8.
- IV fluids
- Lasix (can worsen K)
- Calcitonin (inhibits bone resorption, takes 2-3 days)
- IV bisphosphonates (inhibits dissolution and bone resorption, takes 2-4 days with the nadir at 4-7 days).
- If lymphoma – prednisone.
- Severe: Hemodialysis.
- Calcium chloride vs calcium gluconate:
- An amp of 10% calcium gluconate contains 8.9 mg/mL of elemental calcium. An amp of 10% calcium chloride provides a threefold higher concentration of elemental calcium – 27.2 mg/mL.
- Calcium chloride is more irritating and is more likely to cause tissue necrosis
- Calcium gluconate must be hepatically metabolized
- If calcium gluconate is not available, substitute calcium chloride at one-third of the dose and it is preferable to use central access or a larger catheter in a more proximal site.