Biomaterial Database

A simple method for determining physiologically active calcium and magnesium concentrations in critically ill patients. 1987

G P Zaloga, and R Wilkens, and J Tourville, and D Wood, and D M Klyme

Total serum calcium and magnesium concentrations are frequently abnormal in critically ill patients despite the occurrence of normal ionized levels. Since ultrafilterable calcium and magnesium values approximate ionized levels, we evaluated the accuracy of ultrafilterable levels in critically ill patients. Ultrafilterable serum calcium concentrations were sensitive (95%) and specific (93%) in predicting ionized hypocalcemia. Total serum calcium values were sensitive (93%) but lacked specificity (50%) in predicting ionized hypocalcemia. Total serum magnesium concentrations were sensitive (100%) but not specific (73%) in predicting ultrafilterable hypomagnesemia. We conclude that ultrafilterable calcium concentrations offer an alternative to ionized calcium measurements when an ion-selective electrode is not available. In addition, ultrafilterable magnesium levels may reflect more accurately the true ionized magnesium concentrations than total serum magnesium values.

UI	MeSH Term	Description	Entries
D007362	Intensive Care Units	Hospital units providing continuous surveillance and care to acutely ill patients.	ICU Intensive Care Units,Intensive Care Unit,Unit, Intensive Care
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014462	Ultrafiltration	The separation of particles from a suspension by passage through a filter with very fine pores. In ultrafiltration the separation is accomplished by convective transport; in DIALYSIS separation relies instead upon differential diffusion. Ultrafiltration occurs naturally and is a laboratory procedure. Artificial ultrafiltration of the blood is referred to as HEMOFILTRATION or HEMODIAFILTRATION (if combined with HEMODIALYSIS).