Infection associated with the external ventricular derivation catheter: preliminary data

Introduction

The purpose of this study was to evaluate the total drainage time, the risk of infection associated with external ventricular derivation (EVD) and the most prevalent infective agent during the use of EVD drainage in patients on the ICU.

Methods

During 15 months (8 August 2008 to 28 October 2009), all patients on the neurovascular ICU who had an EVD inserted were studied prospectively. Each 3 days we analysed cerebral spinal fluid (CSF) samples for cell count, biochemistry and sputum. CSF cultures were evaluated three times a week combined with an antibiogram. Not included were the cultures that persisted with the same result (agent), considering only a new agent until negativity of the culture and clinical resolution. We excluded patients admitted with EVD from another hospital.

Results

Were included 46 patients, in which were obtained a total number of 66 EVDs. Thirty-five EVDs (53,03%) had associated ICP monitoring. A total 65.21% of patients were female. The mortality of patients was 36.95% (17 deaths). Among infected catheters, infection was confirmed in approximately 7.1 days after the EVD was installed. However, the catheters discharged with negative culture or without growth of a new agent remained approximately 6.15 days on the brain ventricle of patients. Registered were 20 positive bacteriological cultures of CSF (30.30%) among the total EVDs. The most prevalent organisms were Acinetobacter baumanii on nine cultures (45%), Pseudomonas aeruginosa on six cultures (30%), Serratia rubidaea on one culture (5%), Streptococcus oralis on one culture (5%), Klebsiella ornithinolytica on one culture (5%), Estafilococcus coagulase negative on one culture(5%), Stenotrophonas maltophylia on one culture (5%).

Conclusions

Some previous studies show a substitution from positive Gram agents to negative Gram agents on infections associated with EVD. The study has shown a prevalence of P. aeruginosa and A. baumanii on infection associated with the EVD catheter, which are also more prevalent in the ICU environment. This study reinforces that, in case of suspected CNS infection associated with catheter EVD (meningitis, ventriculitis, or abscess), we can start empirical antimicrobial coverage for Gram-negative infections, including intraventricular administration (intrathecal) as Polymixin B.