adjust_calcium_for_albumin: Adjust total calcium for albumin

In LS31/clinicalcalculations: Clinical calculations

Description

Most of the protein-bound calcium is bound to albumin. In hypoalbuminaemia and hypocalcaemia, the (clinically relevant ionised) calcium level will be underestimated. Therefore, total calcium levels may be adjusted/corrected for albumin. An alternative approach is measuring ionised calcium levels directly. Calcium is adjusted using the formula: \text{calcium}_\text{measured} + 0.025 (\text{albumin}_\text{normal} - \text{albumin}_\text{measured})).

Usage

adjust_calcium_for_albumin(calcium, albumin, normal_albumin = 40)

Arguments

calcium	Measured total calcium level (mmol/l).
albumin	Measured albumin level (g/l).
normal_albumin	Normal value of albumin (g/l) (40 by default).

Value

Albumin-adjusted calcium level (mmol/l), or NA if any parameters are NA.

Caveats

Adjustments for albumin are quite poor substitutes for measuring ionised calcium.

References

Bushinsky, D. A. & Monk, R. D. Calcium. The Lancet 352, 306–311 (1998)..

See Also

units::set_units(), units::drop_units()

LS31/clinicalcalculations documentation built on Nov. 20, 2020, 6:59 a.m.