USES
- measurement of blood concentration of various forms of haemoglobin
DESCRIPTION
- a device that uses spectrophotometry to measure relative blood concentrations of oxyhemoglobin, carboxyhemoglobin, methemoglobin, and reduced haemoglobin
METHOD OF INSERTION AND/OR USE
- a laboratory test involving a blood sample heated to 37 C and subjected to light of various length and assesses absorption spectra.
- does not require pulsatile flow
- measures MetHb, COHb and other forms of Hb
- uses many other wavelengths
OTHER INFORMATION
- measures either venous, arterial or capillary oxygenation
COMPLICATIONS
Causes of HIGH Co-oximetery and LOW Pulse Oximetry Readings
- Poor peripheral perfusion
- Ambient light
- Poor probe contact
- Dyes (e.g. methylene blue)
- Tricuspid regurgitation (and other causes of venous pulsations)
Causes of LOW Co-oximetry and HIGH Pulse Oximetry Readings
- COHb
- MetHb
- Radiofrequency interference
- Leukocyte larceny (oxygen consumption by cells in the collection tube, may also occur in situations such as severe thrombocytosis)
References and links
FOAM and Web resources
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