Influence of Ward Environments on External Ventricular Drain Infections: A Retrospective Risk Factor Analysis

Ventriculostomy-related infection (VRI) is one of the most severe and common complications of external ventricular drains (EVD). Ward environment is closely related to hospital-acquired infection, but its role in EVD infection is unclear. For some other recognized risk factors, clinical evidence also remains complicated and undetermined. We aimed to evaluate ward environment including multi-bed accommodation and intensive care unit (ICU) stay as potential risk factors for VRI, as well as to confirm those already known factors. We reviewed EVDs retrospectively in our center between January 2012 and January 2017. Univariable and logistic regression analysis were performed to identify risk factors for EVD-related infection. A total of 284 patients who underwent EVD procedure were included. Thirty-six (12.7%) developed EVD-related infection. Univariable analysis revealed that the infection group had longer intensive care unit (ICU) stay (6.81 vs. 3.65 days, p = 0.045) but multi-bed accommodation showed no statistical difference between the two groups (p = 0.404). Univariable analysis also showed VRI patients had lower pre-operational Glasgow Coma Scale (6.89 vs. 9.32, p = 0.001), longer drainage placement duration (11.4 vs. 8.30 days, p < 0.001), greater numbers of cerebrospinal fluid (CSF) sampling (3.89 vs. 1.73, p < 0.001), higher percentage of pre-operational artificial airway status (50.0% vs. 18.1%, p < 0.001), and higher percentage of intracranial hemorrhage diagnosis (88.9% vs. 73.8%, p = 0.048). Logistic regression analysis demonstrated longer post-operational ICU stay (>5 days, odds ratio [OR] = 3.21, p = 0.026) as independent risk factor for EVD-related infection. Other independent risk factors included CSF sampling counts (>3, OR = 5.14, p <0.001), EVD duration (>7 days, OR = 3.85, p = 0.028), and pre-operational artificial airway status (OR = 2.85, p = 0.038). Longer post-operational ICU stay, frequent CSF sampling, longer duration of EVD placement, and pre-operational intubation are independent risk factors for EVD infection. Multi-bed accommodation and bilateral EVD placement have no substantial influence on VRI risk.