Abbott i-STAT 1 System Manual page 405

Method Comparison (mmol/L or mEq/L)
Beckman
Synchron
n
Sxx
Syy
Slope
Int't
Sy.x
Xmin
Xmax
r
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
obtained from skin puncture samples may vary due to hemolysis or an increase in tissue fluid from improper
technique during the collection procedure.
Interference studies were based on CLSI guideline EP7-A2.
CLSI guideline unless otherwise indicated.
When added to a plasma pool the following substances (at the concentrations indicated) were found
to interfere with the i-STAT potassium assay:
Substance
Bromide
Nithiodote (sodium thiosulfate)
The following substances are known not to significantly interfere with the i-STAT potassium assay at
the stated test concentrations:
Substance
Acetaminophen
Acetylcysteine
Ascorbate
Bromide
ß-Hydroxybutyrate
Lactate
Magnesium Chloride
Salicylate
Note 1: Bromide has been tested at two levels: the CLSI recommended level and a therapeutic plasma
concentration of 2.5 mmol/L. The latter is the peak plasma concentration associated with halothane
Rev. Date: 15-Jul-16
Kodak
CX 3 Ektachem™ 700
®
189 142
0.060 0.031
0.055 0.059
0.97 1.06
0.02 -0.15
0.076 0.060
2.8 3.0
5.7 9.2
0.978 0.993
and red blood cells during the clotting process. Potassium values
1
Test Concentration (mmol/L)
Art: 714174-01O
Nova
STAT
Profile 5
®
192
0.065
0.055
0.99
-0.01
0.112
2.8
5.8
0.948
Test concentrations used were as per the
6
37.5
Decreased i-STAT Potassium results.
16.7
8
Test Concentration
Interference
Use another method.
See Note 1 below.
See Note 2 below.
(mmol/L)
1.32
10.2
0.34
2.5
6.0
7
6.6
1.0
4.34
K - 3