Serum procalcitonin monitoring for differential diagnosis of ventriculitis in adult intensive care patients

The objective of our study was to assess the value of serum procalcitonin (PCT) monitoring in the differential diagnosis of ventriculitis in adult intensive care (ICU) patients. We analyzed 15 consecutive patients with ventriculitis in which a ventricular catheter had been inserted and contrasted these data with the observations in 10 patients with community-acquired bacterial meningitis. Cerebrospinal fluid (CSF) and blood samples were collected daily to assess serum PCT, C-reactive protein (CRP) and CSF leukocyte count. PCT levels were normal or slightly elevated in patients with ventriculitis with either positive or negative CSF bacterial culture but elevated in patients with bacterial meningitis. A PCT cut-off value of 1.0 ng/ml or more showed a specificity of 77% and a sensitivity of 68% for ventriculitis with positive CSF bacterial culture. Serum PCT levels reflected more accurately the time phases of disease during therapy. We conclude that the monitoring of serum PCT alone is not helpful for the differential diagnosis of ventriculitis, in contrast to that of bacterial meningitis. The value of PCT as an additional marker with which to assess the efficacy of therapy in ventriculitis is suggested, but requires further assessment.