CT before lumbar puncture
5% had mass effect on ct
- pts with abnormal cts:
--- age >60,immunecompromised, cns dz, sz within one wk, aloc, unable to answer questions, unable to follow
commands, gaze palsy, abnrm visual fields, arm/ leg
drift, abnrml speech.
- features not assoc with abnormal ct- race,
insurance, htn, h/o parameningeal dz like otitis/
sinusitis
- if none of the above, chance of normal ct is 97%
- even if do lp with mildly abnormal ct, none had
brain herniation
- ct before lp resulted in longer ER stay and delay in
abx
- if no abnormal findings, neg predictive value is 97% - so don't need ct routinely
- if have abnormal finding, abx first, then ct then lp
7/2/09 PANI