gms | German Medical Science

Objective: There are different regimes of external ventricular drainage concerning catheter materials, prophylactic antibiosis, and the interval after which ventricular catheters are to be exchanged in order to prevent or limit infections. In our institution we have left the practice of catheter replacement after fixed intervals, and undertook a retrospective study to see whether complication rates justify our approach.

Methods: In our institution, cerebrospinal fluid (CSF) from external ventricular drainages is routinely monitored with respect to cytological and microbiologic state: CSF cell counts and protein content as well as bacterial spectra are recorded. These data were retrospectively collected from one hundred patients whose state had required treatment by ventriculostomy and external CSF drainage. CSF data were correlated to hematological and clinical data: white blood cell counts, C-reactive protein levels, and body temperature. Additionally, the reason of drainage removal or exchange was recorded.

Results: Most patients (61%) suffered from supra- or infratentorial bleeding of various causes (aneurysm, hypertensive intracerebral or cerebellar bleeding) with consecutive hydrocephalus, followed by tumors (11%) and trauma (9%). Average time of catheter application was 14 days (0–49), and 83% of all catheters were of standard non-impregnated silicon. Silver-impregnated catheters were used in 10%. In 16% of all patients, CSF cultures became positive at some point from day 4 onwards (average day 15). In two thirds of these patients (11% of total) drainage removal or exchange became necessary due to infection, mostly because of bacterial species from the fecal flora, while culture of staph. epidermidis tended to be non-significant with respect to CSF infection. Due to small numbers, no valid statements concerning different complications of silver-impregnated catheters can yet be made.

Conclusions: With CSF infection being variably defined, literature gives complication rates between 0 and 22%, mostly ranging around 10%. Catheter replacement in fixed intervals as a method to prevent infection is controversial (e.g. Lozier et al. 2002, republ. 2008). Our data show an infection rate well within the reported frame and do not strengthen the concept of catheter exchange on a regular base.