title: Heparinization of samples for plasma ionized calcium measurement.
abstract: Maintenance of normal plasma ionized calcium concentration forms part of the management of the critically ill patient; it is, therefore, important to measure accurately plasma ionized calcium. We have compared the ionized calcium concentration of blood samples heparinized with a carefully measured amount of heparin with that of blood samples heparinized in the conventional fashion. The amount of heparin in the deadspace of a syringe was demonstrated to artifactually lower the plasma ionized calcium concentration. Samples for plasma ionized calcium measurement should be heparinized with a measured quantity of heparin, since the conventional technique introduces an unknown and probably excessive quantity of heparin into the syringe deadspace.
authors.affiliation: Department of Anesthesiology, University of Utah Medical Center, Salt Lake City.
authors.forename: M P
authors.initials: MP
authors.lastname: Heining
authors.forename: W S
authors.initials: WS
authors.lastname: Jordan
mesh_terms: D000818:Animals; D001800:Blood Specimen Collection / Q000379:methods*; D002118:Calcium / Q000097:blood*; D003422:Critical Care; D004285:Dogs; D006493:Heparin
chemical_list: D006493:Heparin; D002118:Calcium