Abbott i-STAT 1 System Manual page 397

SODIUM/NA
Sodium is measured by ion-selective electrode potentiometry. In the calculation of results for sodium,
concentration is related to potential through the Nernst equation.
The i-STAT System uses direct (undiluted) electrochemical methods. Values obtained by direct methods
may differ from those obtained by indirect (diluted) methods.
See below for information on factors affecting results. Certain substances, such as drugs, may affect
analyte levels in vivo.
2
If results appear inconsistent with the clinical assessment, the patient sample should be retested using
another cartridge.
Intended Use
The test for sodium, as part of the i-STAT System, is intended for use in the in vitro quantification of
sodium in arterial, venous, or capillary whole blood.
Sodium measurements are used for monitoring electrolyte imbalances.
Contents
Each i-STAT cartridge contains one reference electrode (when potentiometric sensors are included in
the cartridge configuration), sensors for the measurement of specific analytes and a buffered aqueous
calibrant solution that contains known concentrations of analytes and preservatives. For cartridges that
contain a sensor for the measurement of sodium, a list of reactive ingredients is indicated below:
Reactive Ingredient
+
Sodium (Na )
Metrological Traceability
The i-STAT System test for sodium measures sodium amount-of-substance concentration in the plasma
fraction of arterial, venous, or capillary whole blood (dimension mmol L
Sodium values assigned to i-STAT's controls and calibration verification materials are traceable to the
U.S. National Institute of Standards and Technology (NIST) standard reference material SRM956. i-STAT
System controls and calibration verification materials are validated for use only with the i-STAT System
and assigned values may not be commutable with other methods. Further information regarding
metrological traceability is available from Abbott Point of Care Inc.
Expected Values
Test/Abbreviation
Sodium/Na mmol/L (mEq/L)
*The i-STAT System can be configured with the preferred units.
Rev. Date: 15-Jul-16
Minimum Quantity
121 mmol/L
Reportable
Units* Range
100–180
Art: 714173-01P
1
) for in vitro diagnostic use.
-1
Reference
Range
3
138 – 146