There is no single clinical sign or laboratory or microbiologic measure that can be used to differentiate ventriculitis from sterile inflammation in patients with external cerebrospinal fluid (CSF) drains, according to results of a systematic review and meta-analysis published in Neurology.
External ventricular CSF drains are associated with a risk for drain-associated ventriculitis. According to guidelines by the Infectious Disease Society of America, CSF cultures are the most important test to establish the diagnosis of drain-associated ventriculitis. Therefore, researchers conducted a systematic review and meta-analysis to assess the diagnostic value of clinical factors as well as biochemical or microbiologic measures for diagnosis of drain-associated ventriculitis.
Following a search in MEDLINE, EMBASE, and CENTRAL electronic databases, the researchers identified articles published between 1984 and 2018 that provided results on external ventricular catheter infections. Indications for drain placement consisted of subarachnoid hemorrhage, intraventricular and intracerebral hemorrhage, hemorrhage not otherwise specified, traumatic brain injury, and obstructive hydrocephalus caused by a brain tumor.
The meta-analysis included 42 studies (20 prospective and 22 retrospective studies). Of the total 3035 participants in the studies, drain-associated ventriculitis developed in 697 (23%). The most common pathogen identified was coagulase-negative staphylococci (32% of patients).
Fever was present in 116 of 162 (72%) patients with drain-associated ventriculitis compared with 80 of 275 (29%) patients without ventriculitis. Several studies reported on documented elevation in leukocyte count among 74 of 80 patients with drain-associated ventriculitis (93%) compared with 30 of 95 patients without ventriculitis (32%).
Of 156 cases of drain-associated ventriculitis, 125 were CSF culture positive (80%) and 31 were culture negative (20%). Gram stain was positive in 44 of 81 patients with confirmed drain-associated ventriculitis (54%). Combined, polymerase chain reaction testing on ribosomal RNA was positive on 54 of 78 CSF samples (69%).
Of note, several studies reported strong associations between polymorphonuclear cells in CSF, CSF cell counts, higher CSF protein concentration, and lower CSF glucose concentrations in patients with drain-associated ventriculitis compared with those who did not have drain-associated ventriculitis. However, the results of these studies were attenuated by other studies that demonstrated no significant differences in such measures between patients with and without ventriculitis.
The researchers acknowledged several limitations of the study, including data obtained from small, single-center, retrospective case-control or case-series; differences between studies in the reference standards and the inclusion criteria; and missing data on clinical and CSF characteristics.
“Clinical factors and biochemical and microbiological measures have limited diagnostic value in differentiating between ventriculitis and sterile inflammation in patients with external CSF drains,” conclude the researchers.
Dorresteijn KRIS, Jellema K, van de Beek D, Brouwer MC. Factors and measures predicting external CSF drain-associated ventriculitis: a review and meta-analysis. Neurology. 2019;93:964-972.