Siemens Rapidlab 1200, Operator'S Manual, Page: 369 / 448

Rapidlab 1200 Operator’s Guide: System Specifications E-9
02087462 Rev.V
Interference Testing for Rapidlab 1200 CO-oximetry
Siemens performed interference testing to demonstrate the specificity of the
Rapidlab 1200 systems CO-oximetry module.
The table shows the interference level tested along with the average change in
blood results (test result spiked - control result unspiked) for each of the sensors.
The probability of the mean effect being zero was calculated, and those with less
than a 5% chance (p < 0.05) were considered statistically significant. For those
effects which were statistically significant, a mean effect > 0.5 g/dL for tHb or >
1.0% for the CO-ox fractions was considered clinically significant.
The reported effects for methylene blue at 25 and 40 mg/L are the simple mean
effect (spiked mean–control mean). For sulfhemoglobin, the mean effect was
corrected using the difference observed between the spike and control from an
additional reference method (gas chromatography or mass spectrophotometry
depending on analyte) which was not subject to interference. Sample preparation
differences alone, between the spiked and control samples, accounted for some of
the observed differences and by subtracting out that contribution using the
reference method, the true interference can be estimated.