Physiological monitoring of the head-injured patient

Infection Rates in Standard vs. Hydrogel Coated Ventricular Catheters

Background:

Infection related to external ventricular drain (EVD) use is a common neurosurgical complication. Modified catheters with a hydrophilic surface may impede bacterial adherence and thereby reduce catheter related cerebrospinal fluid (CSF) infection.

Methods:

A prospective randomized clinical trial compared the occurrence of CSF infection related to use of either standard silastic or hydrogel coated EVD catheters (Bioglide®, Medtronic). Enrolment was available to all adult neurosurgery patients undergoing placement of a first EVD, at three university centers. The catheters were presoaked in a low concentration of bacitracin solution for 5-10 minutes prior to insertion. Bacterial infection was defined by heavy growth in a single CSF sample or light / medium growth in two consecutive samples. A secondary analysis was also conducted for “probable” CSF infection, including patients started on antibiotics after light / medium growth in a single CSF sample. Statistical analyses included Kaplan-Meier survival curve estimates accompanied by Log Rank and Breslow tests.

Results:

There were 158 randomized patients available to assess for EVD related infection of CSF. The two study groups had similar clinical characteristics including average duration of EVD use (8±4 days). Definite CSF infection occurred in seven and probable infection in another six (8% total). Infection incidence rose steadily from day 2 (1%) to day 11 (11%). There was no difference of daily occurrence of EVD infection between the two catheter types.

Conclusion:

Infection remains a common hazard in the use of EVD, and we found no reduction of infection using the hydrogel-coated catheters when presoaked in low concentration bacitracin solution.

Prolonged external ventricular drainage with percutaneous long-tunnel ventriculostomies

External ventricular drainage has been used extensively for management of several neurosurgical disorders. The main limitation of this procedure has been the high risk of infection, especially with prolonged drainage. In an effort to minimize the risk of infection, the authors have used a new ventriculostomy technique that involves tunneling the ventricular catheter subcutaneously to an exit site in the lower chest or upper abdomen. This report describes the results of this procedure on 100 consecutive cases. Patients requiring emergency ventriculostomies had short-tunnel ventriculostomies placed at the bedside that were converted to long-tunnel ventriculostomies in the operating room within 5 days. The average duration of drainage was 18.3 days (range 5-40 days). Cerebrospinal fluid was routinely sent for Gram staining and culture to monitor for infection. Prophylactic antibiotic medications were administered only perioperatively. No infection was observed during the first 16 days of drainage in any patient. The overall incidence of infection was 4% and blockage occurred in 6% of the cases. In this series the incidence of ventricular infection was 2.37 per 1000 ventricular drainage days, one of the lowest reported incidences of infection in the literature. This procedure provides a simple and effective method of maintaining long-term ventricular drainage with a very low risk of infection or blockage.