Sorted By Test Name - Mayo Medical Laboratories

CAI
8378
IONCG
300235
restriction, facilitating differentiation from patients with hypercalcuria caused by hyperparathyroidism,
hyperthyroidism, Paget's disease, or "renal leak" type of calciuria as seen in renal tubular acidosis.
Reference Values:
800-1,200 mg/kg
Reference values apply to all ages.
Clinical References: 1. Abrams SA, Schanler RJ, Yergey AL, et al: Compartmental analysis of
calcium metabolism in very-low-birth-weight infants. Pediatr Res 1994 October;36(4):424-428 2.
Ditscheid B, Keller S, Jahreis G: Cholesterol metabolism is affected by calcium phosphate
supplementation in humans. J Nutr 2005;135(7):1678-1682 3. Nishimuta M, Inoue N, Kodama N, et al:
Moisture and mineral content of human feces - high fecal moisture is associated with increased sodium
and decreased potassium content. J. Nutr Sci Vitaminol 2006 April;56:121-126
Calcium, Ionized, Serum
Clinical Information: Ionized calcium, which accounts for 50% to 55% of total calcium, is the
physiologically active form of calcium. Low ionized calcium values are often seen in renal disease,
critically ill patients, or patients receiving rapid transfusion of citrated whole blood or blood products.
Increased serum ionized calcium concentrations may be seen with primary hyperparathyroidism, ectopic
parathyroid hormone-producing tumors, excess intake of vitamin D, or various malignancies. Nomograms
have been used to calculate ionized calcium from total calcium, albumin, and pH values. However,
calculated ionized calcium results have proven to be unsatisfactory. A Mayo study of 114 patients found
significant differences between ionized and total calcium in 26% of patients.
Useful For: Assessing calcium states during liver transplantation surgery, cardiopulmonary bypass, or
any procedure requiring rapid transfusion of whole blood in neonates and in critically ill patients
Second-order test in the evaluation of patients with abnormal calcium values
Interpretation: Serum ionized calcium concentrations 50% below normal result in severely reduced
cardiac stroke work. With moderate to severe hypocalcemia, left ventricular function may be profoundly
depressed. Ionized calcium values are higher in children and young adults. Ionized calcium values vary
inversely with pH, approximately 0.2 mg/dL per 0.1 pH unit change.
Reference Values:
Males
1-19 years: 5.1-5.9 mg/dL
> or =20 years: 4.8-5.7 mg/dL
Reference values have not been established for patients that are or =18 years: 4.8-5.7 mg/dL
Reference values have not been established for patients that are