One concept that has generated a lot of attention in preventing nosocomial infections is use of catheters and other implanted devices that are impregnated with either antibiotics or other antimicrobial substances (eg. silver). Such have been used for urinary catheters, endotracheal tubes, etc.
External ventricular catheters used in neurosurgery are associated with CSF infections in 2% to 23% of cases. Some centers have begun to use prophylactic antibiotics in attempt to reduce the occurrence of such nosocomial infections. But prophylactic antibiotics also have the potential to lead to emergence of antibiotic-resistant organisms and predispose patients to C. difficile infections. So, in theory, a ventricular catheter impregnated with an antimicrobial agent might prevent nosocomial infection and not predispose to these other undesirable complications.
A neurosurgery unit in Hong Kong has piloted use of such an antibiotic-impregnated external ventricular catheter (Wong 2010). They randomized patients undergoing emergency neurosurgical operations to either the antibiotic-impregnated ventricular catheter (impregnated with clindamycin and rifampicin) or a conventional catheter plus prophylactic intravenous antibiotics (ampicillin-sulbactam and ceftriaxone). The study was not blinded, however, since the catheters were of different colors.
They found no significant difference in nosocomial infections between the two groups, nor differences in the incidence of CSF infection, ICU length of stay, total acute hospital stay, or functional outcome and the rate of other complications was not different. They concluded that the antibiotic-impregnated catheters were as effective as systemic prophylactic antibiotics in preventing CSF infection and that nosocomial infection rates were not significantly different. They also suggest that the antibiotic-impregnated catheters are more cost-effective when the catheters must in place for 6 days or more.
Keep in mind that use of antibiotic “prophylaxis” in such cases is a controversial topic.
Our advice on how to avoid CSF infections due to ventricular catheters: avoid unnecessary use of them! A few years ago a neurosurgery resident was considering a quality improvement project to see what interventions reduced the rate of CSF infections in patients with ventricular catheters. We noted that the most important outcome should not be the rate of catheter-associated CSF infections but rather the total number of CSF infections in patients undergoing the neurosurgical procedures. Just as with catheter-associated urinary tract infections (CAUTI’s), the most important intervention is avoiding use of the catheter in the first place. In almost every neurosurgery unit we’ve looked at, particularly those in academic or teaching settings, we find lots of ventricular catheters of questionable indication. So before you implement a program of either prophylactic antibiotics or antibiotic-impregnated catheters, make sure you have clearcut criteria for when a ventricular catheter should be used and monitor your compliance with those criteria.
Wong GKC, Ip M, Poon WS, et al. Antibiotics-impregnated ventricular catheter versus systemic antibiotics for prevention of nosocomial CSF and non-CSF infections: a prospective randomised clinical trial. Journal of Neurology, J Neurol Neurosurg Psychiatry 2010; 81: 1064-1067