Silver catheters fight infection in neurosurgery patients
MedWire News: Use of silver-impregnated catheters cuts cerebrospinal fluid (CSF) infection rates in patients requiring an external ventricular drain (EVD), shows a randomized trial.
The infection risk was almost halved, report Nicole Keong (Addenbrooke's Hospital, Cambridge, UK) and colleagues in Neurosurgery. They note that the Silver-Impregnated Line Vs EVD Randomized (SILVER) trial had a pragmatic design, with no attempt made to control use of antibiotics for systemic infections.
"The current findings may therefore be a dilution of the true individual effect of silver impregnation in the absence of any antibiotic therapy," they say.
"We are therefore confident that the results are translatable, and relevant on account of the pragmatic approach to the study design.
CSF infection, identified by microscopy or culture, occurred in 21.4% of 140 patients assigned to use of a plain catheter compared with just 12.3% of 138 patients given a silver-impregnated catheter. The high overall rate was because the researchers enrolled patients with high infection risk, ie, those with severe injury and with a heavy intracranial blood load, who were likely to need extended catheter use. Most patients required an EVD for between 5 and 15 days.
The infection profiles also differed between the groups. Infection peaked at day 5 in both groups, but the plain catheter group had a second peak at about day 10, whereas the silver catheter group did not. Similar organisms caused infections in both groups, and there were similar rates of atypical infections.
Use of silver catheters was also associated with a reduced risk for patients requiring a ventriculoperitoneal (VP) shunt, which was needed in 29.4% of this group, compared with 55.2% of those given a plain catheter.
"Given the known high costs of treating ventriculitis, later shunt insertion and management of late complications over the subsequent months and years, the introduction of silver-impregnated catheters would seem to make sound economic and clinical sense," say Keong et al.
They say that use of silver-impregnated catheters may avoid the theoretical antibiotic resistance problems that could occur with use of antibiotic-impregnated catheters, which are also undergoing testing. But they stress that a direct comparison of the two types of catheter will be needed.
By Eleanor McDermid