What is your approach to bloody CSF (that does not clear with sequential tubes) in a patient without acute finding on a head CT?

I still think there is value looking for xanthochromia if CSF obtained >12 h after onset of symptoms. Yes, there are occasional false positives of xanthochromia with traumatic taps, but if a patient presents to ED with sudden onset of a severe headache, negative CT, lots of RBCs on tube 1 and tube 4...