User's Manual

i15 Blood Gas and Chemistry Analysis System User Manual Parameters
- 135 -
samples with K
+
values spanning the measurement range.
Parameter N Expected Observed Swr bias %Recovery
K
+
9 3.40 3.35 0.04 -0.05 98.5%
9 4.00 4.01 0.03 0.01 100.3%
9 9.37 9.36 0.20 -0.01 99.9%
Linearity was estimated using reference materials and reference methods. Three replicates of
each level of materials were analyzed in parallel on the i15 Blood Gas and Chemistry Analysis
System and the Rapidpoint 400 system. Reference materials used were RNA Medical
®
CVC123
Calibration Verification Controls, and they were traceable to NIST standards. In the table below, Sy.x
refers to the standard error of estimate.
Parameter N Slope Intercept
Correlation
Coefficient
Sy.x Range
K
+
15 1.0 -0.04 0.99997 0.03787 1.82 – 12.09
In the comparison study, samples were analyzed in parallel on the i15 Blood Gas and Chemistry
Analysis System and the Rapidpoint 400 system. Two replicates of each sample were analyzed
on each system.
Parameter N Slope Intercept
Correlation
Coefficient
Sy.x Range
K
+
215 1.0068 -0.0409 0.9983 0.0594 2.55 – 6.70
12.5.4 Interfering Substances
Aqueous sample was spiked by addition of a potentially interfering substance to the following
test concentration to test for interferences. Twelve replicates of both the spiked sample and the
unspiked sample were tested on two i15 Blood Gas and Chemistry Analysis Systems with one lot
of test cartridges. The interference was computed using the difference between the mean of the
spiked sample and the unspiked sample.
The following substances were tested and found not to be clinically significant for the K
+
measurement: 24mmol/L hydroxyurea, 1.0mmol/L magnesium, 20mmol/L lactate, 4.00mmol/L
salicyte, 37.5mmol/L bromide, and 20mmol/L β-hydroxybutyrate.