carboxyhemoglobin


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carboxyhemoglobin

 [kahr-bok″se-he´mo-glo″bin]
hemoglobin in which the sites usually bound to oxygen are bound to carbon monoxide molecules; carbon monoxide has an affinity for hemoglobin over 200 times that of oxygen. See carbon monoxide poisoning.

car·box·y·he·mo·glo·bin (HbCO),

(kar-bok'sē-hē'mō-glō'bin),
A fairly stable union of carbon monoxide with hemoglobin. The formation of carboxyhemoglobin prevents the normal transfer of carbon dioxide and oxygen during the circulation of blood; thus, increasing levels of carboxyhemoglobin result in various degrees of asphyxiation, including death.

carboxyhemoglobin

/car·boxy·he·mo·glo·bin/ (-he´mo-glo″bin) hemoglobin combined with carbon monoxide, which occupies the sites on the hemoglobin molecule that normally bind with oxygen and which is not readily displaced from the molecule.

carboxyhemoglobin

(kär-bŏk′sē-hē′mə-glō′bĭn)
n.
The compound that is formed when inhaled carbon monoxide combines with hemoglobin, binding more tightly than oxygen and rendering the hemoglobin incapable of transporting oxygen.

carboxyhemoglobin

[kärbok′sēhē′məglō′bin, -hem′-]
Etymology: L, carbo + Gk, oxys, sharp, haima, blood; L, globus, ball
a hemoglobin variant produced by the exposure of hemoglobin to carbon monoxide. Carbon monoxide from the environment is inhaled into the lungs, absorbed through the alveoli, and bound to hemoglobin in the blood, blocking the sites for oxygen transport. Oxygen levels decrease, and hypoxia and anoxia may result. Also spelled carboxyhaemoglobin. See also carbon monoxide poisoning, oxyhemoglobin.

carboxyhemoglobin

Haemoglobin (Hb) with irreversibly bound carbon monoxide (COHb). COHb levels reflect CO exposure, which increases in fires and with exposure to car exhaust; Some COHb occurs naturally as a product of Hb catabolism and due to increased turnover of Hb in newborns, coupled with reduced efficiency of the infant’s respiratory system, leading to increased COHb.

Carboxyhaemoglobin levels
• < 2%: Non-smokers;
• 2%–12%: Smokers;
• > 20%: Toxic;
• > 50%: Lethal.

carboxyhemoglobin

COHb Hb in which carbon monoxide–CO is irreversibly bound

car·box·y·he·mo·glo·bin

(kahr-bok'sē-hē'mŏ-glō'bin)
A stable union of carbon monoxide with hemoglobin. The formation of carboxyhemoglobin prevents the normal transfer of carbon dioxide and oxygen during the circulation of blood; thus, increasing levels of carboxyhemoglobin result in various degrees of asphyxiation, including death.
Synonym(s): carbon monoxide hemoglobin, carboxyhaemoglobin.

Carboxyhemoglobin (COHb)

Hemoglobin that is bound to carbon monoxide instead of oxygen.

carboxyhemoglobin

hemoglobin combined with carbon monoxide, which occupies the sites on the hemoglobin molecule that normally bind with oxygen and which is not readily displaced from the molecule; exposure to carbon monoxide thus results in cellular anoxia. See also hemoglobin.
References in periodicals archive ?
Distribution of presentation complaints according to carboxyhemoglobin levels Group 1, n (%) Group 2, n (%) Nausea-vomiting 80 (31.
Reddy said he could foresee using a lower carboxyhemoglobin level of 3% in middle schools, for example, to reach young smokers, even though this cutoff lowered the specificity of the test to 72%.
Using exhaled carbon monoxide and carboxyhemoglobin to evaluate the effectiveness of a chimney stove model in Peru.
Among the five decedents whose carboxyhemoglobin (COHb) levels were tested, levels ranged from absent to mildly elevated (range: zero to 5%) (Table), indicating that carbon monoxide was unlikely to have been the primary cause of death (although the durations of exposure to methylene chloride and receipt of oxygen during resuscitation efforts, two factors that can affect COHb levels, were not known).
Additionally, the binding of CO to hemoglobin to form carboxyhemoglobin (HbCO) causes conformational changes to hemoglobin's tetrameric structure, thereby increasing the affinity of the remaining heme groups for 02.
The AVOXimeter 4000 whole-blood oximeter is capable of multiple-band spectro-photometric analysis, which allows the researcher to quickly determine the oxyhemoglobin, deoxyhemoglobin, methemoglobin, and carboxyhemoglobin percentage and total hemoglobin (derived/calculated) in a whole blood sample.
Cooximetry uses four wavelengths of light to measure the absorptive characteristics of oxy- and deoxyhemoglobin, methemoglobin, and carboxyhemoglobin species.
In addition to total hemoglobin, the Masimo device will provide non-invasive measurement of carboxyhemoglobin and methemoglobin.
Principal analyst Richard Sykes tested the samples and found carboxyhemoglobin, a chemical formed when carbon monoxide enters the blood.
To put it technically, Carbon monoxide (CO) replaces oxygen in the bloodstream, causing a condition known as carboxyhemoglobin (COHb) saturation.