OPTIMedical OPTI CCA-TS - Page 208

K-2 Operator’s Manual – OPTI CCA-TS
POTASSIUM ANALYTES
Interferences
The OPTI CCA-TS K
+
sensor has no measurable interference from Na
+
variation within the range 100-
190 mmol/L.
The OPTI CCA-TS 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-TS K
+
sensor has no interference from ammonia or ammonium ion present at normal
physiologic levels (below 100 µmol/L). At hyperammonemia (plasma levels of 300 µmol/L),
the OPTI CCA-TS K
+
sensor will show a potassium offset of +0.4 mmol/L, and at extreme
hyperammonemia (plasma levels of 3000 µmol/L), the OPTI CCA-TS 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 uoride cause signicant interferences to the electrolyte sensors.
The following exogenous interferents were quantied in tonometered plasma, showing interferences to
dyes which typically have short half-lives within the body before being metabolized by the liver.
Substance amount K
+
change (mmol/L)
Sodium uorescein 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-TS system. Colored materials,
including prociency testing materials, may interfere with the ion measurement, or fail to be
properly aspirated.
Reproducibility
Typical Within-Run (Swr), Between-Day (Sdd) and Total (ST) Precision is determined from 1 run per
day with 2 replicates per run for 20 days on each of two OPTI CCA instruments. Potassium values are
expressed in mmol/L.
Material mean Swr (CV%) Sdd (CV%) ST (CV%)
OPTI CHECK PLUS
(aqueous control solution)
Level 1 2.61 0.004 (0.2) 0.026 (1.0) 0.026 (1.0)
Level 2 4.50 0.005 (0.1) 0.030 (0.7) 0.030 (0.7)
Level 3 5.58 0.006 (0.1) 0.048 (0.9) 0.47 (0.4)
Serum 7.11 0.010 (0.1) 0.08 (1.1) 0.08 (1.1)
Reduced Bovine Hemoglobin 2.92 0.004 (0.1) 0.02 (0.8) 0.02 (0.8)
Solution