The association between ventriculostomy - Related infection and clinical outcomes: A systematic review and meta-analysis

Performance of routine surveillance diagnostics of external ventricular drain-associated infections in a critical care setting: a retrospective cohort study

INTRODUCTION

External ventricular drains (EVDs) are crucial for treating neurocritically ill patients but are complicated by feared EVD-associated infections (EVDIs) in up to 35% of all inserted drains, contributing significantly to morbidity, mortality and account for a significant proportion of intensive care unit (ICU) antibiotic use. However, the lack of a universal definition for EVDIs leads to inconsistent diagnostic criteria across studies, with a concern of substantial overtreatment with broad-spectrum antibiotics. This study aimed to evaluate if current EVDI surveillance parameters can be optimized to better distinguish true from suspected EVDI.

METHODS

We conducted a retrospective cohort study at the Karolinska University Hospital ICU, including all patients treated with EVDs between 2006 and 2023, excluding patients with primary central nervous system (CNS) infections. EVDI surveillance included biweekly sampling and cultures from cerebrospinal fluid (CSF). Patients were categorized as no infection (NI), suspected infection (SI), or verified infection (VI) based on culture results and treatment status. We employed classification and regression analyses to identify predictors of VI.

RESULTS

Among 1,828 patients with EVDs, 29.8% were initiated on antibiotic treatment due to suspected infection and 4.1% were found to have culture confirmed infections. The main finding is that current accepted diagnostic parameters cannot distinguish aseptic inflammation from true EVDI. In multivariable logistic analysis the best models exhibited low accuracy, with a pseudo- R 2 of only 0.06. CSF lactate was the most important metric in a univariable setting, however with a cut-off of 8.9 mmol/L it showed low discrimintive ability and limited clinical utility.

CONCLUSIONS

In this study we evaluate current accepted EVDI surveillance methods in, to our knowledge, the largest cohort of paired samples to date. We find that current surveillance parameters cannot distinguish aseptic CNS inflammation from true EVDIs in an ICU setting. This contributes to a significant antibiotic overtreatment, with 25% of our entire cohort being unnecessarily initiated on broad-spectrum antibiotics, a number we expect can be generalized. We identify a large clinical problem with consequences on both a individual and population level, and recommend that future research focus on evaluating new techniques, such as fast bedside sequencing methods.

A systematic review of reviews on ventriculostomy related infection definitions: A fundamental problem

Despite being a common, well-recognized and important complication to External Ventricular Drainage (EVD), a consensus definition for Ventriculostomy Related Infections (VRI) has not yet been established. We conducted a review to qualitatively assess definition heterogeneity and objectivity among Randomized Controlled Trials (RCTs); and investigated systematic reviews, meta-analyses, and reviews of the literature for definition citation accuracy and common methodological approaches and points of discussion related to VRI definitions. RCTs were grouped into arbitrarily chosen infection rate brackets to examine the hypothesized correlation between broader definitions and higher infection rates in RCTs. A literature search was conducted via Ovid in the Embase, MedLine and Cochrane databases from all years until the 8th of January 2025. Using Covidence, two authors (MH, AA) independently evaluated records, including studies that had ≥ 1 VRI definitions and numerical VRI rates. We identified 12 definitions in 13 RCTs, documenting pronounced disagreement. Cumulative rates for "definitive" VRI (8.4%) were lower than "suspected" VRI (13.5%). Qualitatively assessed, studies with narrow definitions presented lower VRI rates. All 17/17 meta-analyses and systematic reviews, and 15/19 literature reviews cited ≥ 1 definition inaccurately. Trial results may change based on definition choice. Definition heterogeneity was not sufficiently accounted for in meta-analyses. All literature-based studies were confounded by definition heterogeneity. Previously reported findings based on meta-analytical methodologies may be invalid, and inaccurately presented definitions could give a false impression of trial comparability. A consensus set of definitions are necessary to allow comparison between studies, and should be constructed to account for the intended use since sensitivity and specificity may have different weight depending on the context.

The VEntriculostomy-Related Infection Score: An Antibiotic Stewardship Tool in Ventriculostomy-Related Infections

BACKGROUND AND OBJECTIVES

Diagnosing ventriculostomy-related infection (VRI), a common complication after external ventricular drainage (EVD), is challenging and often associated with delayed initiation of antibiotic therapy. We aimed to develop a stewardship score to help in the decision of antibiotic therapy initiation when VRI is suspected.

METHODS

This retrospective, single-center cohort study included patients admitted to the intensive care unit after EVD placement who were suspected of having healthcare-associated ventriculitis and/or meningitis between January 1, 2012, and August 31, 2022. A multiple logistic regression model was used to identify factors associated with the development of healthcare-associated meningitis or ventriculitis after EVD placement.

RESULTS

A total of 331 patients were included. Eighty-one (23%) patients developed VRI between January 1, 2012, and August 31, 2022, whereas 250 (77%) did not (from January 1, 2018, to August 31, 2022). VRI-associated factors were EVD count >1 (odds ratio [OR] 3.69, P < .001), EVD duration >8 days (OR 6.71, P < .001), immunosuppression (OR 3.45, P = .028), recent neurosurgery (OR 7.74, P < .001), cerebrospinal fluid leak (OR 6.08, P < .001), and prophylactic antimicrobials (OR 0.26, P < .001). The VEntriculostomy-Related Infection score (VERI) score categorized VRI risk into 4 levels, with an area under the curve of 0.84.

CONCLUSION

The VERI score is a robust, predictive tool for assessing the risk of VRI in patients with EVD, potentially guiding more judicious use of antibiotic therapy in the intensive care unit setting.

The incidence of ventriculostomy-related infections as diagnosed by 16S rRNA polymerase chain reaction: A prospective observational study

BACKGROUND

Ventriculostomy-related infections (VRIs) are reported in about 10 % of patients with external ventricular drains (EVDs). VRIs are difficult to diagnose due to clinical and laboratory abnormalities caused by the primary neurological injury which led to insertion of the EVD. Polymerase chain reaction (PCR) of the cerebrospinal fluid (CSF) may enable more accurate diagnosis of VRI. We performed a prospective cohort study to measure the incidence of VRI as diagnosed by 16S rRNA PCR.

METHODS

Patients admitted to intensive care with a primary diagnosis of subarachnoid haemorrhage (SAH), traumatic brain injury (TBI), or intracerebral haemorrhage (ICH), who required an EVD, were assessed for inclusion in this study. Data were extracted from the electronic medical record, bedside charts, or from a prospectively collected database, the Neuroscience Outcomes in Intensive CarE database (NOICE). 16S rRNA PCR was performed on routinely collected CSF as per laboratory protocol. VRI was also diagnosed based on pre-existing definitions.

RESULTS

237 CSF samples from 39 patients were enrolled in the study. The mean patient age was 55.7 years, and 56.4 % were female. The most common primary neurological diagnosis was SAH (61.5 %). The incidence of a positive PCR was 2.6 % of patients (1 in 39) and 0.8 % of CSF samples (2 in 237). The incidence of VRI according to pre-published diagnostic criteria was 2.6 % - 41 % of patients and 0.4 % - 17.6 % of CSF samples. 28.2 % of patients were treated for VRI. Pre-published definitions which relied on CSF culture results had higher specificity and lower false positive rates for predicting a PCR result when compared to definitions incorporating non-microbiological markers of VRI. In CSF samples with a negative 16S rRNA PCR, there was a high proportion of non-microbiological markers of infection, and a high incidence of fever on the day the CSF sample was taken.

CONCLUSIONS

The incidence of VRI as defined as a positive PCR was lower than the incidence of VRI according to several published definitions, and lower than the incidence of VRI as defined as treatment by the clinical team. Non-microbiological markers of VRI may be less reliable than a positive CSF culture in diagnosing VRI.

Ventriculostomy-associated infection (VAI) in patients with acute brain injury-a retrospective study

BACKGROUND

Ventriculostomy-associated infection (VAI) is common after external ventricular drains (EVD) insertion but is difficult to diagnose in patients with acute brain injury. Previously, we proposed a set of criteria for ruling out VAI in traumatic brain injury. This study aimed to validate these criteria. For exploratory purposes, we sought to develop and validate a score for VAI risk assessment in patients with different types of severe acute brain injury.

METHODS

This retrospective cohort study included adults with acute brain injury who received an EVD and in whom CSF samples were taken over a period of 57 months. As standard non-coated bolt-connected EVDs were used. The predictive performance of biomarkers was analyzed as defined previously. A multivariable regression model was performed with five variables.

RESULTS

A total of 683 patients with acute brain injury underwent EVD placement and had 1272 CSF samples; 92 (13.5%) patients were categorized as culture-positive VAI, 130 (19%) as culture-negative VAI, and 461 (67.5%) as no VAI. A low CSF WBC/RBC ratio (< 0.037), high CSF/plasma glucose ratio (> 0.6), and low CSF protein (< 0.5g/L) showed a positive predictive value of 0.09 (95%CI, 0.05-0.13). In the multivariable logistic regression model, days to sample (OR 1.09; 95%CI, 1.03-1.16) and CSF WBC/RBC ratio (OR 34.86; 95%CI, 3.94-683.15) were found to predict VAI.

CONCLUSION

In patients with acute brain injury and an EVD, our proposed combined cut-off for ruling out VAI performed satisfactorily. Days to sample and CSF WBC/RBC ratio were found independent predictors for VAI in the multivariable logistic regression model.

Epidemiology, clinical profile, and outcomes of CSF-diversion catheter-related infections - Prospective cohort study results from a single quaternary neurosurgery referral centre

BACKGROUND

Device-associated CNS infections is a major subgroup of healthcare associated CNS infections. Healthcare-associated ventriculitis or meningitis differs considerably from community-acquired meningitis in its epidemiology, pathogenesis, clinical presentation and management.

OBJECTIVES

This study aimed to identify the infection rates, the associated risk factors, and outcomes of these life-threatening infections.

METHODS

This was a 2-year single center prospective cohort study. Patient's clinical data, laboratory parameters, treatment and their outcomes were collected using data collection tool, and device days were collected from the hospital information system (HIS). Patients were categorised using IDSA criteria as contamination or colonisation or infection. Cox regression model was used for multivariate analysis to estimate hazard risk.

RESULTS

A total of 578 CSF diversion catheters were inserted in 472 patients. The average rate for EVD and LD infection were 11.12 and 11.86 per 1000 device days respectively. The average infection rates for VP and LP shunts were 6% and 5.2% per procedure, respectively. The commonest etiological agent causing CSF diversion catheter-related infection (CDRI) was Klebsiella pneumoniae (n = 14, 40%). The risk factors which were independently associated with increased infection risk by cox regression analysis were drain insertion ≥7 days [HR:11.73, p -0.03], posterior approach of EVD insertion (occipital) [HR:9.53, p - 0.01], pre-OP ASA score>3 [HR:8.28, p - 0.013] presence of EVD/LD leak [HR: 17.24, p < 0.0001], male gender [HR:2.05, p-0.05] and presence of associated peri-operative scalp infections [HR:3.531, p-0.005]. Shift to narrow spectrum surgical prophylactic antibiotic [Coefficient: -1.284, p-0.03] and reduction in CSF sampling frequency [Coefficient: -1.741, p-0.02] were found to be negatively associated with CDRI.

CONCLUSIONS

The study demonstrated drain insertion ≥7 days, posterior approach of EVD insertion, presence of EVD/LD leak, male gender and presence of associated peri-operative scalp skin and soft tissue infections were associated with increased risk of infection.