Rates and determinants of ventriculostomy-related infections during a hospital transition to use of antibiotic-coated external ventricular drains

Abstract

Object The authors evaluated the rates of ventriculostomy-related infections (VRIs) after antibiotic-coated extraventricular drains (ac-EVDs) were introduced as the standard of care. Methods A retrospective chart review was conducted of adult patients admitted to NewYork-Presbyterian Hospital neurological intensive care unit in whom an EVD was placed between February 2007 and November 2009, excluding individuals receiving EVDs due to an infection of a primary device. Three time periods were defined depending on type of EVD in use: Period 1, conventional EVDs; Period 2, either ac-EVDs or conventional EVDs; and Period 3, ac-EVDs. Definite/probable VRIs that occurred during the 3 periods were evaluated and established as determinants of VRIs by using a Cox proportional hazards model. Prolonged systemic antibiotics were given for the duration of EVD placement in each of the 3 periods per institutional policy. Results Data from 141 individuals were evaluated; mean patient age was 53.8 ± 17.2 years and 54% were female. There were 2 definite and 19 probable VRIs. The incidence of definite/probable VRI (per 1000 person-catheter days) decreased from Period 1 to 3 (24.5, 16.2, and 4.4 in Periods 1, 2, and 3, respectively; p < 0.0001). Patients with VRIs were more likely to be female than male (23.7% vs 3.1%, p < 0.003) and have had an EVD in place for a longer duration, although there was no significant difference among the 3 periods (7.9 ± 6.7 [Period 1], 8.1 ± 7.1 [Period 2], and 8.6 ± 5.8 [Period 3] mean days; p = 0.87, ANOVA). Analysis of effect modification in a stepwise model showed that period, age, and age and female interaction were significant predictors of VRIs. The period was the strongest predictor of VRI (p = 0.0075). After adjustment for age and age and sex interaction, the survival rate was 53% at the end of Period 2 and 91% at the end of Period 3. Conclusions Rates of VRIs have decreased with the addition of ac-EVDs to the routine use of prolonged systemic antibiotics at the authors' institution.