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Clinical Pathology Laboratory - Available Test
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Hitachi Indices
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| The Hitachi autoanalyzer provides estimates of the degree of lipemia,
hemolysis and icterus in the sample. This is accomplished by using
3 different bichromatic wavelengths (480/505, 570/600 and 660/700
nm) to measure absorbance, with a correction formula compensating
for spectral overlap. These indices are included at the bottom of
our chemistry report under "special blood chemistry". In
addition, depending on the amount of these interferences in the sample,
we provide a guideline as to how the results of chemistry tests may
be affected by these interferences (see image below). However, clinical
judgement (i.e. correlating laboratory results with clinical signs
and disease process) should be used to determine if the results of
the listed tests are inaccurate or affected by the interferences.
Furthermore, the effect of these interferences are species-dependent.
For example, dogs have low K+ in their mature erythrocytes, therefore
red cell lysis (hemolysis) should not increase K+ artefactually in
this species, whereas it does in horses, cattle, and sheep. |
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Lipemic index |
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| The lipemic index (units) is based on turbidity obtained with a
lipid emulsion and is linear up to 1000 units. Outlined below in the
table is a guide as to how our laboratory evaluates the lipemic index
obtained from the Hitachi. |
Guide to Lipemia Index
| Lipemia index |
Gross appearance |
| 30 - 60 |
slightly lipemic (hazy) |
| 60 -120 |
moderately lipemic (milky) |
| > 120 |
markedly lipemic (creamy) |
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Hemolytic index |
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| The hemolytic index (units) is approximately equivalent to the hemoglobin
concentration (mg/dL) and is linear to 1000 units. Free hemoglobin
in the sample has little or no affect on most assays unless the level
is very high. Hemoglobin-based oxygen carriers interfere with many
chemistry tests. The hemolytic index in samples from animals treated
with these products is very high, however the interference is not
predictable from the guidelines we provide. We provide a separate
comment, listing known effects on our results, if we know the animal
has received this treatment. |
Guide to Hemolysis Index
| Hemolysis index |
Gross appearance |
| 20 -100 |
slightly hemolyzed (pink tinged) |
| 100 - 400 |
moderately hemolyzed (red) |
| > 400 |
markedly hemolyzed (dark red) |
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Icteric index |
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| The icteric index (units) is approximately equal to the total bilirubin
concentration (mg/dL), rounded to the nearest whole number, and is
linear to 60 units. Although measurement of total bilirubin may be
affected by hemolysis and lipemia (values are artefactually high),
the icterus index is not affected and can be used to determine if
there is hyperbilirubinemia. For example, a lipemic serum sample from
a dog that has an ICTERUS index result of "4" has a bilirubin
concentration approximately 3.5 to 4.4 mg/dL, which indicates that
the dog has hyperbilirubinemia. However, this artefactual increase
of total bilirubin concentration in lipemic and hemolyzed samples
is less apparent with our new total bilirubin reagent. |
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