Pediatric emergency medicine trisk 2874 2874
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this salt can be infused peripherally via a large vein. The use of calcium
gluconate is usually favored as it is less likely to result in tissue damage if
extravasation occurs. As concentrated forms are irritating to veins, calcium
salts should be diluted in dextrose and water or saline. The final
concentration of calcium gluconate should be 50 mg/mL, and calcium
chloride should be diluted to 20 mg/mL. Calcium should not be prepared or
infused with fluids containing phosphate or bicarbonate given the risk of
precipitation of insoluble salts. The dose for IV bolus of calcium gluconate
in the setting of cardiac disturbance is 50 to 100 mg/kg/dose infused over 3
to 5 minutes and for tetany is 100 to 200 mg/kg/dose infused over 5 to 10
minutes. Intravenous calcium should not be infused more rapidly given the
risk for cardiac arrhythmia, bradycardia, and arrest. Cardiac monitoring and
serial monitoring of the serum calcium level should be performed. Repeat
boluses should be provided until the symptoms resolve, and then a slower
infusion should be continued.
For patients with either chronic hypocalcemia or milder degrees of acute
hypocalcemia without severe symptoms, oral calcium is preferred.
Numerous forms of oral calcium salts are available. Calcium carbonate is
readily available and well tolerated. If either hypoparathyroidism or vitamin
D deficiency is suspected, vitamin D replacement should be provided to
optimize enteral absorption. The overall management goal of chronic
hypocalcemia is to achieve acceptable serum calcium while avoiding
hypercalcemia and excessive hypercalciuria.
Hypercalcemia
Hypercalcemia results when the influx of calcium into the extracellular
space exceeds the rate of deposition into bone or renal capacity for
excretion. This most commonly results from accelerated bone resorption
secondary to increased PTH activity, but may also occur due to excessive
absorption from the gastrointestinal tract, or decreased renal excretion.
Excessive exposure to vitamin D will increase intestinal calcium and
phosphate absorption and would be associated with a depressed PTH level.
In addition to exogenous sources of vitamin D, granulomatous disorders
may be associated with increased 1,25-dihydroxyvitamin D activity and
promote absorptive hypercalcemia. Accelerated bone resorption would be
anticipated in primary, secondary, and tertiary hyperparathyroidism. Jansen
