An elderly male w/ prior renal transplant p/w confusion and sepsis presumed 2/2 urinary source. His confusion worsened despite treatment of a UTI, and concern for meningitis grew. He was ultimately diagnosed with VZV encephalitis, but passed away despite treatment initiation.
The Rational Clinical Exam: Does this patient have acute meningitis?
Check out these sensitivities of HPI and PEx findings from the 1999 JAMA Rational Clinical Exam article (PMID 10411200) – the take home point being thatthe classic triad (fever, AMS, headache) is rare and there should be a very LOW threshold to LP any patient with even 2 of these, especially if not responding to treatment or immunocompromised.
Who should obtain a head CT before LP?
According to the 2004 IDSA guidelines, a CT is indicated to exclude a mass lesion or increased ICP (which could lead to herniation with LP) in adults with the following risk factors:
-Immunocompromised state (including HIV or medications)
-History of CNS disease (including stroke or prior infection or mass lesion)
-Seizure within one week of presentation
-Abnormal level of consciousness
-Focal neurologic deficit
*Note that the guidelines do not actually include an age cut-off (which I think I said in report)