Precise CO-oximetry at the POC takes the guesswork out of transfusion


The CO-oximeter in Radiometer’s blood gas analyzers is widely regarded for its ability to measure, among other parameters, total hemoglobin with consistently high accuracy.

When it comes to total hemoglobin, measuring accuracy may mean the difference between transfusing a patient or not, dramatically impacting patient care and health care costs. Choosing the right technology with measured, rather than calculated hemoglobin and an improved preanalytical phase can ensure the same clinical accuracy in the point of care as in the central lab.

Radiometer’s CO-oximeter ensures:

Full CO-oximetry at 128 wavelengths
Radiometer’s 128-wavelength spectrophotometer measures a full range of CO-oximetry parameters. 128 wavelengths ensure that all the details of the measured spectrum are revealed, providing a highly precise spectral blueprint. The advantage of having this vital information is that our CO-oximeter is able to detect and subsequently suppress interferences from commonly seen substances.

Automatic detection and correction of interfering substances
The spectra of the common interferences are stored in the analyzer software. The analyzer compares the model spectrum with the measured spectrum. Any deviations caused by interferences (such as lipids, HbF, SHb, pH, Cardio Green, Evans Blue, betacarotene, Patent Blue V, methylene blue, HiCN) are detected and suppressed, ensuring measuring accuracy.

Radiometer’s CO-oximeter is equipped with a neon lamp which generates constant spectral lines. The function of the spectral lines is to serve as references to ensure that there is no drift in the 128 wavelengths used in the spectrophotometer. The neon lamp controls that any deviations are automatically detected and corrected, also contributing to constantly high measuring quality.

High accuracy and precision
The net result of the design of Radiometer’s CO-oximeter is measurement accuracy and precision.

The CO-oximeter on the ABL800 FLEX is able to measure ctHb with a repeatability of less than 0.15 g/dL on ctHb levels between 7.0 g/dL and 25.0 g/dL.

For a typical transfusion threshold of 7.0 g/dL, Radiometer’s CO-oximeter performs just as accurately when compared to lab methods.

A recent study conducted at the University of California Davis Medical Center [1] comparing measured tHB on the Radiometer’s ABL90 FLEX analyzer to that of the lab ((Beckman LH780) and competing point-of-care devices, showed the following results:


The superior precision shown by the ABL90 FLEX analyzer means that measured hemoglobin results from the analyzer provide a more solid foundation for clinicians when deciding whether or not to transfuse, dramatically impacting patient care and health care costs.

No influence of non-hemolyzed blood
The Radiometer CO-oximeter hemolyzes blood samples with ultrasound waves inside the measuring cuvette itself. With the blood being hemolyzed inside the measuring cuvette, the blood sample does not have to be moved after hemolyzation. This eliminates the possibility of the measured sample being mixed with non-hemolyzed blood, and thereby ensures accuracy (Fig. 1).

Fewer clots
CO-oximeter clots are a frequent and serious problem. Radiometer’s CO-oximeter is equipped with intra-cuvette hemolyzation. The measuring cuvette destroys potential clots ultrasonically during the hemolyzation process, helping to ensure sample integrity (Fig. 2).

Fewer bubbles
The design of the Radiometer CO-oximeter prevents the formation of air bubbles by carrying out the intracuvette ultrasound hemolyzation under overpressure. An overpressure of one atmosphere is maintained not only during the hemolyzing process but until the measurement has been completed. Such maintenance improves the precision of the measurement (Fig. 3).

No deposits
After each measurement, Radiometer’s CO-oximeter ultrasonically cleans the cuvette’s glass walls, knocking loose deposits before they build up. This eliminates the need to replace the glass on the CO-oximeter – a costly and time-consuming procedure with other analyzers – and keeps the CO-oximeter maintenance-free (Fig. 4).

Your choice of CO-oximeter impacts patient care. For more information, listen to the on-demand webinar Blood Conservation at the POC: The right technology can make a difference presented by Dr. Nam K. Tran, PhD, MS, FACB of the University of California, Davis.




1. Tran, Nam K et al. Clinical Significance of Accurate Total Hemoglobin Measurements. AACC Poster 2016.

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