Clinical parameters do not predict infection in patients with external ventricular drains: a retrospective observational study of daily cerebrospinal fluid analysis

Abstract

A retrospective review was conducted of patients with external ventricular drains (EVDs) in situ in order to ascertain the utility of daily cerebrospinal fluid (CSF) analysis in such patients. All laboratory requests for CSF analysis, which were sent to the Microbiology Department, Auckland City Hospital, New Zealand, were reviewed to identify patients with EVDs in situ. The patients' clinical records were reviewed and information was obtained regarding their age, ethnicity, indication for EVD, duration of EVD, CSF analysis results, daily temperatures, Glasgow Coma Scale (GCS) and the presence of other infections. For CSF samples that grew organisms, the patients' notes were reviewed to ascertain whether the organism was a contaminant or was representative of EVD-associated ventriculitis. A total of 454 CSF specimens from 60 patients were reviewed. Of the 56 CSF specimens that were culture-positive, 40 (71 %) were found to reflect clinical infection. Routine CSF analysis identified nine episodes of EVD-associated ventriculitis. Coagulase-negative staphylococci and Staphylococcus epidermidis were the most common isolates and were associated with ventriculitis approximately half of the time. Gram-negative isolates were less frequently isolated, but, when present, were always associated with ventriculitis. This study found that patient temperature and GCS did not allow early prediction of EVD-associated ventriculitis.

Yesterday, Today & Tomorrow: Best Practice for CSF Sampling of an EVD to Minimise Patient Risk

“…(Hoefnagel et al, 2008;Kitchen et al, 2011;Korinek et al, 2005;Lwin, Low, Choy, Yeo & Chou, 2012;Muttaiyah et al, 2008;Pfisterer, Muhlbauer & Reinprechtet, 2003;Williams et al, 2011;Williamson et al, 2014).…”

“…Their prospective methodology tends to yield more accurate results given the ability to control certain points and variables. Pfisterer et al, (2003) concluded as did Muttaiyah et al, (2008) that patients were generally very unwell and unable to communicate signs and symptoms of an infection and therefore daily specimens were required. The focus of Pfisterer's et al, (2003) study was mainly looking at the association of drainage time and infection.…”

“…In a retrospective study by Muttaiyah et al, (2008), a daily sample of CSF was taken and an analysis was conducted looking mainly at clinical parameters predicting infection. From the pathology results of the CSF samples collected, Muttaiyah et al, (2008) indicated that a change in Glasgow Coma Scale (GCS) score and/or a change in temperature of a patient with an EVD was not a reliable link to indicate daily CSF sampling rather, it increased the risk of ventriculitis. They also noted that these neurological and metabolic changes were not a reliable indicator for early prediction of ventriculitis.…”

“…When decontamination of the port was discussed the specific decontaminating solution was omitted. Muttaiyah et al, (2008) and Pfisterer et al, (2003) both stated they used a chlorhexidine 2% alcohol combination to swab their chosen EVD port or sample site. Pfisterer et al, (2003) used chlorhexidine ethanol solution, stating a meticulous disinfection of the port site was completed when manipulating the EVD system.…”

“…The retrospective study by Muttaiyah et al, (2008) stated that samples were obtained from a proximal port. No rationale for port selection was discussed, despite concluding that larger studies are required to identify if reduced frequency of sampling is safe.…”