Treatment of acute hypocalcemia in critically ill multiple-trauma patients.

Background: Recent data indicate that critically ill, adult multiple trauma patients receiving specialized nutrition support commonly experience hypocalcemia (ionized serum calcium [iCa] < or =1.12 mmol/L). However, validated methods for the treatment of acute hypocalcemia are lacking.
Methods: The efficacy of a single dose of calcium gluconate using an empiric IV calcium gluconate graduated dosing regimen was evaluated in 37 patients. Patients with an iCa of 1-1.12 mmol/L (mild hypocalcemia) were provided 1-2 g of IV calcium gluconate. Patients with an iCa of <1 mmol/L (moderate to severe hypocalcemia) were given 2-4 g. The calcium gluconate was infused at a rate of 1 g/h in a small-volume admixture. Serum iCa determination was repeated on the following day.
Results: One to 2 g of IV calcium gluconate was effective in normalizing iCa for 23 out of 29 patients (79%) with mild hypocalcemia and 2-4 g was effective for 3 of 8 patients (38%) with moderate to severe hypocalcemia. The individual response to calcium therapy (g/d) or when normalized to body weight (mg/kg/d) was highly variable.
Conclusions: One to 2 g of IV calcium gluconate were effective for most patients with mild hypocalcemia; however, treatment of moderate to severe hypocalcemia with 2-4 g of IV calcium gluconate was often unsuccessful. Further study with frequent serial ionized serum calcium and phosphorus determinations and electrocardiographic monitoring appears to be indicated for patients with moderate to severe hypocalcemia.