Roche OMNI C, Instructions For Use Manual

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4 Measurement
Instructions for Use, Roche OMNI C, Rev. 4.0, December 2002
4-1
4 Measurement
4.1 Preanalytics
4.1.1 Sample collection
Follow the usual applicable safety precautions when drawing blood samples. When
handling blood samples, there always exists the danger of transmission of HIV, hep-
atitis B and C viruses or other pathogens transmissible by blood. Employ suitable
blood sampling techniques in order to reduce risk to personnel.
Always wear protective gloves and suitable protective clothing.
Please refer to NCCLS document M29-T2, "Protection of Laboratory Workers from
Infectious Disease Transmitted by Blood, Body Fluids, and Tissue – Second Edition"
for guidelines and additional information about handling blood samples.
Sample acquisition
Only qualified personnel may perform the collection of blood needed for analytical purpos-
es.
The puncture site may never be squeezed! Mixing the blood sample with tissue fluid
may lead to the premature onset of clotting despite sufficient heparinization of the
sample collection containers! Incorrect sample collection or the use of an unsuit-
able sample collection container may lead to errors and discrepancies in the mea-
surement values.
See, for example, NCCLS document H11-A2, "Percutaneous Collection of Arterial Blood
for Laboratory Analysis – Second Edition", Approved Standard, May 1992, for detailed
information about blood sampling, storage, and handling.
Acceptable anticoagulants
The only clot inhibitors that may be used for analyses in the Roche OMNI C are heparin
salts. Other clot inhibitors, such as EDTA, citrate, oxalate, fluoride, and ammonium-based
materials have significant influence on the blood's pH and other parameters and may not be
used for this reason.
Sample collection especially for tHb, SO
2
and Hct measurement
Whole blood, especially for the analysis of tHb, SO
2
and Hct, must be thoroughly mixed
immediately before analysis in order to achieve consistent distribution of red blood cells
and plasma before insertion of the sample.
Carefully rotate the sample about two axes using your hand or a mechanical device or insert
a metal disk or ball in the syringe before collecting the sample. Shortly before using the sam-
ple, carefully shake the syringe. The up and down motion of the disk or ball inside the
syringe cylinder ensures consistent mixing.
Refer to NCCLS document C25-T, vol. 12 No.11, "Fractional Oxyhemoglobin, Oxygen Con-
tent and Saturation, and Related Quantities in Blood: Terminology, Measurement, and
Reporting", Tentative Guidelines, July 1992.