r3enal-exam 1-calcium

primarily intracellular, huge reserve in bone

1000-1300 mg/d (elemental calcium)

8.5-10.5 mg/dl, unbound is biologically active portion (45% is ionized)

use if alb level is <3.5 because measured value is falsely low, corrected calcium=(4-measured albumin) X 0.8 + measured calcium, if corrected calcium 8.5-10.5, assume ionized calcium WNL, if corrected calcium <8.5 assume decreased ionized calcium=hypocal

decreased protein binding, increase percent of ionized ca

increased protein binding, decrease in ionized ca, can lead to symptomatic hypoca

>10.5 mg/dL

>13 mg/dL

hyperparathyroidsm(large contributor), immobiliation (primarily in children), malignancy(2nd), granulomatous disease, thyrotoxicosis, famillial, tumor secreates PTH like-substances and increases bone reabsorption or factor secreted at site of bone metastasis

thiazides (more mild), Li, calcium supplement, excess antacids, vit D intox, Vit A toxicity, tamoxifen

increases Ca absorption in sm int

increase bone resorption and the release of Ca and phosphate

stones, bones, abd moans and psychic groans, sx usually seen when more than or equal to 13, with malignancy more severe sx

nephrolithiasis, poluria, dehydration, acute renal failure (precipitation of ca and phos)

impaired conc and memory, confusion, stupor, coma, lethargy and fatigue, muscle weakness

bone pain, joint pain

HTN, shortened QT interval on ECG, bradarr, vascular calcification

NV, anor, wt loss, consipation, abd pain, pancreatitis

itching keratitis, conjunctivitis

0.9% NaCl- 200-300 ml/hr IV inf, rapid onset, rehydration and dilutes Ca, increases excretion, AE: volume overload, decrease potassium, decrease Ca by 2-3 mg/dl within 24-48 hrs when used with a diuretic

furosemide: 40-80 mg IV q 1-4 hrs, onset within 4 hrs, increased excretion, AE: vol deplation, decrease pot and mg, use only after rehydrated, prevents renal reabsorption of Calcium

zoledronate is more potent q 4-5 wks vs 30 days, 2nd choice for all, primary for malignacy, onset 24-48 hours

works faster than bis, but requires a test dose, tolerance can develop-rebound increase in ca

inhibitss vit D2 conv to D3(active) and decreases bone turnover, effective for hematologic malignancies and vit A and D toxicity

for hypercalc-used for pts refractory to other tx, need a central IV line, cytotoxic to osteoclasts, lots of AEs

probably would not tx

NS with loop diuretic

NS plus loop + bis(or other)

serum ca, UOP, EKG, VS

corrected calc <8.5 or ionized ca <4.0mg/dl

extravascular deposition-chronic hyperphosphatemia (CKD), acute pancreatitis, hungry bone syndrome, intravascular binding-IV phosphorus, foscarnet, hypercalciuria(loop diuretics)

hypopara, decreased prod or action of vit D(nutritional, phenytoin, barbiturates, steroids), hypomg(decreased dPTH secretion or PTH resistance), Bisphos, calcitonin, cinacalcet

tetany, perioral paresthesias(numbness around mouth), carpopedal spasms, muscle spasms, cramps, pos chvostek's , pos trousseau's

similar to ca channel blocker:prolonged QT interval, acute myocardial failure, HOTN, brady

Irritabilitym memory loss, dep, conf, halluc, seizures

hair loss, brittle, grooved nails, eczema, psoriasis, hyperpig

ELEMENTAL calcium 100-300 mg slow IV(5-10 min) until tetany resolves, calc gluc -preferred-(4.65 mEq or about 93 mg elemental ca/gm OR calc chloride (13.6mEq or 273 mg elemental calc/gm

followed by cont inf, in 1 L bag, of elemental calc at 0.5-2 mg/kg/hr

monitor serum calcium q 4-6 hrs(should return to normal in 4-6) and adjust inf rate accordingly, target calcium is low end of normal

oral calcium salts, carbonate requires acid(tk with meals-most common form, caution in elderly and if on PPIs or H2)only 30-40% absorbed, to increase abs: tk with food, divide into doses <=500mg, add vit D 200-800 IU/day, citrate does not req aicd

vit D+ca supplementation

constipation, potentially kidney stones

already in active form-if underlying kidney fxn

most common forms of vit d