Serum calcium measurement: Total versus free (ionized) calcium

Reducing routine ionized calcium measurement.

BACKGROUND Ionized calcium (iCa) is measured frequently in hospitalized patients, and hypocalcemia is frequently found, seemingly supporting the practice. METHODS We retrieved the results of 58 040 iCa tests and records of intravenous (IV) and oral calcium supplementation from laboratory and hospital information systems and evaluated them for frequency of testing, frequency of hypocalcemia, a...

Whole blood versus serum ionized calcium concentrations in dialysis patients

BACKGROUND/AIMS The aim of this study is to measure the difference of ionized calcium between heparinized whole blood and serum. METHODS We recruited 107 maintenance hemodialysis (HD) patients from our hospital HD unit. The clinical and laboratory data included ionized calcium in serum and in whole blood (reference, 4.07 to 5.17 mg/dL). RESULTS The level of ionized calcium in serum was high...

Serum ionised calcium concentration: measurement versus calculation.

Four hundred and eighteen measurements of serum ionised calcium, total calcium, and protein concentrations were made from 47 normal volunteers, 104 patients with chronic renal failure (33 being treated conservatively and 71 with regular haemodialysis), and 83 renal transplant recipients. The serum ionised calcium concentration was measured with an Orion SS-20 meter and calculated from the total...

Measurement of serum and plasma ionic calcium with the "Space-Stat 20 Ionized Calcium Analyzer".

Ca2+ was measured in sera and plasma from 36 normal subjects (18 men 23-57 years old, and 18 women 20-52 years old) with the Space-Stat 20 Ionized Calcium Analyzer. Within-day and between-day precision (CV) for commercial serum-based specimens varied from 0.64-0.96% and 1.1-3.8%, respectively, depending on their mean concentrations. Plasma and serum showed within-day CV's of 1.05 and 0.79%, res...

Ionized calcium