Calcium in patients on hemodialysis.

Analyzing 415 measurements from 33 patients on chronic maintenance hemodialysis we confirm that 50% of total calcium in the range 1.59 to 3.33 mmol/l gives a valuable approximation to ionized calcium in the range 0.79 to 1.62 mmol/l. However, a small but significant effect of albumin and phosphate on ionized calcium can also be demonstrated. Conventional albumin correction of total calcium using the formula: total calcium + (43 g/l-Albumin g/l).0.017 mmol/g is of poor value in these patients on maintenance hemodialysis.