Objective—To compare direct measurements of
canine oxyhemoglobin (HbO2) saturation and blood
oxygen content (ContO2) in healthy dogs with analyzer-calculated values derived by use of a human HbO2
relationship and with hand-calculated values derived
by use of a canine HbO2 relationship.
Animals—17 healthy dogs.
Procedure—3-mL samples of heparinized arterial and
jugular venous blood were collected from each dog.
The pH, PCO2, PO2, hemoglobin, HbO2, carboxyhemoglobin,
methemoglobin, and ContO2 were measured;
HbO2 and ContO2 were calculated automatically by
analyzers and also hand-calculated. Blood gas analyzer–calculated and hand-calculated HbO2 values were
compared with co-oximeter–measured HbO2 values.
Analyzer-calculated and hand-calculated ContO2 values
were compared with oxygen content analyzermeasured
Results—Hand-calculated HbO2 values for arterial
and jugular venous samples were slightly but significantly
lower than those calculated by a blood gas analyzer
or obtained from a co-oximeter. Hand-calculated
and analyzer-calculated arterial and venous ContO2
were similar to measured values.
Conclusions and Clinical Relevance—Although certain
HbO2 and ContO2 values generated by use of the
different methods were significantly different, these
differences are unlikely to be clinically important in
healthy dogs. (Am J Vet Res 2005;66:1273–1277)