cerebrospinal fluid in subarachnoid haemorrhage

Last reviewed 01/2018

In the first 6 to 12 hours after a subarachnoid haemorrhage, the CSF should be uniformly stained with blood. The physician should be wary of a bloody tap when piercing of a blood vessel during the puncture causes apparent blood in the CSF. This should be ruled out by taking three separate samples which should be equally stained.

12 hours after a subarachnoid haemorrhage the CSF is xanthochromic - i.e. a yellow colour as a result of red blood cell breakdown.

The opening pressure is an important feature to note.

The red blood cells will excite an inflammatory response, i.e. a rise in WCC in CSF, that is most marked after about 48 hours. The cells are predominantly mononuclear cells.