OPTi CCA-TS2, Руководство оператора, Страница: 228 / 299

K-2 Operator’s Manual – OPTI CCA-TS2
POTASSIUM ANALYTES
Interferences
The OPTI CCA K
+
sensor has no measurable interference from Na
+
variation within the range 100-190
mmol/L.
The OPTI CCA K
+
results include an appropriate correction for pH at all values of pH.
This correction may introduce an extra source of variability at the extreme values.
The OPTI CCA K
+
sensor has no interference from ammonia or ammonium ion present at normal
physiologic levels (below 100 µ mol/L). At hyperammonemia (plasma levels of 300 µ mol/L),
the OPTI CCA K
+
sensor will show a potassium offset of +0.4 mmol/L, and at extreme hyperammonemia
(plasma levels of 3000 µ mol/L), the OPTI CCA K
+
sensor will show a potassium offset of +4.4 mmol/L.
Heparin salts are the only acceptable anticoagulants. Other anticoagulants such as citrate, EDTA, oxalate,
and fluoride cause significant interferences to the electrolyte sensors.
The following exogenous interferents were quantified in tonometered plasma, showing interferences to
dyes which typically have short half-lives within the body before being metabolized by the liver.
This testing was done on the OPTI CCA platform, with a standard OPTI style Potassium sensor.
No changes were made to the sensor or the measurement principle, so the interference of the OPTI CCA-
TS2 is equivalent to the OPTI CCA.
Substance Amount K
+
change (mmol/L)
Sodium fluorescein 26 mg/dL -0.7
Cardio (indocyanine) green 0.5 mg/dL -0.4
Methylene blue 25 mg/dL +2.4
Only clear, uncolored quality control materials, such as OPTI CHECK or OPTI CHECK PLUS brand
aqueous controls should be used with the OPTI CCA-TS2 system. Colored materials, including
proficiency testing materials, may interfere with the potassium measurement, or fail to be properly
aspirated.
Reproducibility
Controls
Within run precision (S
wr
) and Total Precision (S
T
), were determined from 2 runs per day with 2 replicates
per run over a period of 20 days following the CLSI guideline EP5-A2. Typical results for 3 different
control levels are shown below.
K
+
(mmol/L) OPTI Check Level 1 OPTI Check Level 2 OPTI Check Level 3
Days Run 20 20 20
Total Average 2.92 4.86 5.92
Within Run St. Dev. (S
wr
) 0.03 0.03 0.03
Within Run % CV 0.9% 0.6% 0.5%
Total Precision St. Dev. (S
T
) 0.03 0.03 0.04
Total % CV 1.0% 0.6% 0.6%