Rev. Date: 12-Jul-11 Art: 714174-00J K - 3
Method Comparison (mmol/L or mEq/L)
Beckman Nova
Synchron Kodak STAT
CX
®
3 Ektachem™ 700 Profile
®
5
n 189 142 192
Sxx 0.060 0.031 0.065
Syy 0.055 0.059 0.055
Slope 0.97 1.06 0.99
Int't 0.02 -0.15 -0.01
Sy.x 0.076 0.060 0.112
Xmin 2.8 3.0 2.8
Xmax 5.7 9.2 5.8
r 0.978 0.993 0.948
Cartridge Comparison
The performance characteristics of the sensors are equivalent in all cartridge configurations. System
difference analysis was performed on 40 patient samples using the i-STAT 6+ and i-STAT EC4+ cartridges.
In the 3.0–5.0 mmol/L range the average difference was 0.049.
Factors Affecting Results*
If heparinized whole blood is allowed to stand before testing, potassium values will first decrease slightly,
then increase over time. Potassium values will increase in iced specimens.
Potassium values from anticoagulated samples are preferred to serum values because 0.1 to 0.7 mmol/L
potassium can be released from platelets
1
and red blood cells during the clotting process. Potassium values
obtained from skin puncture samples may vary due to hemolysis or an increase in tissue fluid from improper
technique during the collection procedure.
Test concentrations used were as per the CLSI guidance document,
7
unless otherwise indicated.
The following substances are known not to significantly interfere with the i-STAT potassium assay at
the stated test concentrations:
Substance
Test Concentration
(mmol/L)
Acetaminophen 1.32
Acetylcysteine 10.2
Ascorbate 0.34
Bromide 37.5
ß-Hydroxybuterate 6.0
8
Lactate 6.6
Magnesium Chloride 1.0
Salicylate 4.34
*It is possible that other interfering substances may be encountered. The degree of interference at concentrations other than those listed might not
be predictable.
To Next Page
Loading...
Need help?
General
