User's Manual

i15 Blood Gas and Chemistry Analysis System User Manual Parameters
- 138 -
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 substances that interfere with the Ca
++
measurement are listed below:
 12.5mmol/L bromide will increase Ca
++
results by 0.07mmol/L.
 37.5mmol/L bromide will increase Ca
++
results by 0.17mmol/L.
The following substances were tested and found not to be clinically significant for the Ca
++
measurement: 24mmol/L hydroxyurea, 1.0mmol/L magnesium, 20mmol/L lactate, 4.00mmol/L
salicyte, and 20mmol/L β-hydroxybutyrate.
NOTE:
It is possible that there are other substances interfering with the Ca
++
measurement.
12.7 Chloride (Cl
-
)
Chloride is measured by potentiometry with an ion-selective electrode. The concentration of
chloride ions is determined by the measured potential through the Nernst equation. The system
uses a direct (undiluted) method to measure chloride, and the obtained values may differ from
those obtained by an indirect (diluted) method.
If test results are inconsistent with the clinical assessment, the sample should be analyzed again
with a new test cartridge.
12.7.1 Intended Use
The chloride test is intended for the quantification of chloride in arterial, venous, or capillary
whole blood samples.
Cl
-
, the major anion in the extracellular space in the body, plays a role in the regulation of the
acid-base balance, and regulates osmotic pressure together with Na
+
.
Monitoring Cl
-
value is vital for patients who suffer from hypertension, cardiac distress, etc.
12.7.2 Traceability
Chloride ion concentration values assigned to calibrant and controls are traceable to NIST
standards.