Co-oximeter
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
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC
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Good article..
Want to know how meth Hb cause low cooxymeter reading compare to pulse oxymeter. Bcz usually pulse oxy shows low values in meth hemoglobin ema.
Thank you