Characterization of chemical meningitis after neurological surgery

We reviewed the records of 70 consecutive adult patients with meningitis af ter a neurosurgical procedure, to determine the characteristics that might help to distinguish a sterile postoperative chemical meningitis from bacter ial infection. The spinal fluid profiles in bacterial and chemical meningit is are similar. The exceptions are that a spinal fluid white blood cell cou nt >7500/muL (7500 x 10(6)/L) and a glucose level of <10 mg/dL were not fou nd in any case of chemical meningitis. The clinical setting and clinical ma nifestations were distinct enough that no antibiotic was administered after lumbar puncture to 30 (43%) of the 70 patients with postoperative meningit is. Chemical meningitis was infrequent after surgery involving the spine an d sinuses. Patients with chemical meningitis did not have purulent wound dr ainage or significant wound erythema or tenderness, coma, new focal neurolo gical findings, or onset of a new seizure disorder. They rarely had tempera tures >39.4 degreesC or cerebrospinal fluid rhinorrhea or otorrhea.