If blood is present in the C.S.f due to a traumatic lumbar puncture, sample No 1 will usually contain more blood than sample No 2. If the blood is due to haemorrahage in the CNS, the two samples will probably appear equally blood-stained. Following a subarachnoid haemorrhoge the fluid may appear xanthochromic, ie. Yellow-red (after centrifuting) The fluid may also appear xanthromic if the patient is jaundiced or when there is spinal constriction.
Whether it contains clots
Clotted C.S.f indicate an increase in fibrinogen.
It occurs when there is spinal construction
Clots can also be found in C.S.f. from patients with pyogenic meningitis (sterile beads to break the clot)
In tuberculosis meningitis, if the C.S.f is allowed to stand for several hours; skin (spider web clot) may form on the surface of the fluid.
This should be transferred to a slide, pressed out, alcohol- fixed, and stained by the Ziel-Neelsen method I.
Perform a cell count (1:2) value 5x106cell/l (sample No 2)
Test the specimen biochemically
Glucose estimation ½ - 2/3 of that found in blood, i.e 2.5 – 4.0 mmol/l (45-72mg%)
Low Glucos →pyogenic meningitidis
Normal →viral miningitis. 162