Xanthochromia

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Xanthochromia

Xanthochromia, from the Greek xanthos (ξανθός) "yellow" and chroma (χρώμα) "colour", is the yellowish appearance of cerebrospinal fluid that occurs several hours after bleeding into the subarachnoid space caused by certain medical conditions, most commonly subarachnoid hemorrhage.[1] Its presence can be determined by either spectrophotometry (measuring the absorption of particular wavelengths of light) or simple visual examination. It is unclear which method is superior.[2]

Physiology

Cerebrospinal fluid, which fills the subarachnoid space between the

cerebral aneurysm.[3]

The most frequently employed initial test for subarachnoid hemorrhage is a

meningismus, and signs of sudden elevated intracranial pressure), but no blood is visible on the CT scan.[1] According to one article, a spinal tap is not necessary if no blood is seen on a CT scan done using a third generation scanner within six hours of the onset of the symptoms. However, this is not standard of care.[5][6]

Heme from red blood cells (RBC) that are in the cerebrospinal fluid because a blood vessel was damaged during the lumbar puncture (a "traumatic tap") has no time to be metabolized, and therefore no bilirubin is present.

After the cerebrospinal fluid is obtained, a variety of its parameters can be checked, including the presence of xanthochromia. If the cerebrospinal fluid is bloody, it is centrifuged to determine its color.

Spectrophotometry

Many laboratories rely on only the color of the cerebrospinal fluid to determine the presence or absence of xanthochromia.

oxyhemoglobin and methemoglobin, which absorb light at 410-418 nm and 403-410 nm, respectively, and also may indicate that bleeding has occurred; to identify substances in cerebrospinal fluid that absorb light at other wavelengths but are not due to bleeding, such as carotenoids;[1][7] and to detect very small amounts of yellow color saturation (about 0.62%) which may be missed by visual inspection, especially when the cerebrospinal fluid has been examined under incandescent lighting or a tungsten desk lamp (corresponding to International Commission on Illumination standard illuminant A).[8]

Visual inspection is the most frequent method used in the United States to assess cerebrospinal fluid for xanthochromia,[10] while spectrophotometry is used on up to 94% of specimens in the United Kingdom.[1][9] There is still disagreement about whether or not to routinely use spectrophotometry or whether visual inspection is adequate, and one group of authors has even advocated measuring bilirubin levels.[11]

See also

References

  1. ^
    S2CID 24393459
    .
  2. PMID 24635988
    .
  3. S2CID 29126514
    .
  4. PMID 7897421
    .
  5. PMID 21768192
    .
  6. S2CID 206934433
    .
  7. ^ a b Edlow, J.A. (July 2004). "The Worst Headache". Morbidity & Mortality Rounds on the Web. Agency for Healthcare Research and Quality. Archived from the original on 2015-05-28. Retrieved 2008-06-22.
  8. ^ a b Williams, Anna (2004). "Xanthochromia in the cerebrospinal fluid" (PDF). Practical Neurology. 126 (4): 174–175.
  9. ^
    PMID 15483297
    .
  10. PMID 11900563
    .
  11. PMID 15608818. Archived from the original
    (PDF) on 8 May 2017. Retrieved 21 May 2016.
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