Rapidlab 1200 Operator’s Guide: System Overview and Intended Use 1-49
02087462 Rev. V
Hyperlipemia can result in artificially increased methemoglobin values.
22,23
High
bilirubin concentrations can falsely increase oxyhemoglobin values. Hyperlipemia
and administration of fat emulsions can increase total hemoglobin values.
Samples frozen with liquid nitrogen can have decreased total hemoglobin
levels.
23
Samples from patients receiving blood substitutes yield unreliable results
for oxygen content because of the different oxygen solubility of the blood
substitutes.
Total Hemoglobin
Total hemoglobin (tHb) is the total of all measured hemoglobin fractions.
21
Total
hemoglobin determination is important in the assessment of oxygen transport and
in the evaluation of anemia. The total hemoglobin reference range for a normal
adult population is 12.0 to 18.0 g/dL.
Total hemoglobin in the CO-ox module is determined using
the following
equation:
tHb = FO
2
Hb + FHHb + FMetHb + FCOHb
In anemia, hemoglobin is low. Numerous spec
ific types of anemia exist but each
stems from 1 of 3 basic causes: Blood loss, destruction of red blood cells, or
failure to produce new red blood cells. In polycythemia, hemoglobin is high.
Polycythemia may be primary, secondary to hypoxia, secondary to dehydration, or
a complication of over-transfusion. Polycythemia may lead to circulatory
complications as a result of increased blood viscosity. Extreme abnormalities of
hemoglobin reflect a potentially life-threatening pathophysiologic state that must
be corrected promptly.
6,24,25
Oxyhemoglobin
Oxyhemoglobin (O
2
Hb) is the fraction of hemoglobin that is actually delivering
oxygen to body tissues.
26
Oxyhemoglobin is reversibly bound to oxygen.
21
The
oxyhemoglobin reference range for arterial blood for a normal population is 94.0
to 97.0%.
The percent of oxyhemoglobin is determined using the following equation:
FO
2
Hb = cO
2
Hb / ctHb x 100
Deoxyhemoglobin
Deoxyhemoglobin (HHb) refers to the hemoglobin capable of binding oxygen.
Deoxyhemoglobin is sometimes referred to as reduced hemoglobin.
21
The
deoxyhemoglobin reference range for arterial blood for a normal population is 0.0
to 5.0%.
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