Cerebrospinal Fluid Infection Associated with Silver-Impregnated External Ventricular Drain Catheters

Risk Factors for Central Nervous System Infections After Craniotomy

The central nervous system (CNS) is less prone to infection owing to protection from the brain-blood barrier. However, craniotomy destroys this protection and increases the risk of infection in the brain of patients who have undergone craniotomy. CNS infection after craniotomy significantly increases the patient's mortality rate and disability. Controlling the occurrence of intracranial infection is very important for post-craniotomy patients. CNS infection after craniotomy is caused by several factors such as preoperative, intraoperative, and post-operative factors. Craniotomy may lead to postsurgical intracranial infection, which is mainly associated with surgery duration, infratentorial (posterior fossa) surgery, cerebrospinal fluid leakage, drainage tube placement, unregulated use of antibiotics, glucocorticoid use, age, diabetes, and other systemic infections. Understanding the risk factors of CNS infection after craniotomy can benefit reducing the incidence of intracranial infectious diseases. This will also provide the necessary guidance and evidence in clinical practice for planning to control intracranial infection in patients with craniotomy.

Risk factors for infection associated with the use of external ventricular drainage: a systematic review with meta-analysis

BACKGROUND

Infection associated with the use of the External Ventricular Drainage (EVD) catheter in neurosurgery is linked to high morbidity and mortality, and various mechanisms are related to its occurrence. This systematic review aims to summarise and update the risk factors associated with EVD-related infection.

METHOD

Systematic review with meta-analysis, utilising grey literature and indexed databases.

FINDINGS

Thirty studies were included, of which nine contributed to the meta-analysis. The reported frequency of EVD-related infection varied from 1.9% to 36%, and the diagnostic criteria for infection were not standardized, with the presence of a positive culture being the most common. The primary microorganisms identified were Staphylococcus sp. and Pseudomonas sp. Key risk factors included duration of catheterisation, frequency of maintenance care, reinsertion, or number of drains. The results of the meta-analysis showed a significant effect in patients with prolonged use of EVDs, with an increase in risk of 1.47 (OR) [CI 95%, 1.03; 2,10] for each day of use (p=0.03), and showed that the number of cerebrospinal fluid collections was higher in the group with infection (p=0.00), while a greater number of EVDs used was related to a significant effect on infection rates (p=0.00), which were revealed from studies with low heterogeneity (I2: 0%).

CONCLUSION

The results indicated studies with high heterogeneity and low quality of evidence, with risk factors associated with the maintenance or management of EVD.

Risk Factors for External Ventricular Drainage-Related Infection: A Systematic Review and Meta-analysis

Background and Objectives

External ventricular drainage (EVD) is one of the most commonly performed neurosurgical procedures, but EVD-related infection constitutes a significant health concern. Yet, little consensus identifies the risk factors for the development of EVD-related infection. Therefore, we performed a meta-analysis to systematically summarize existing evidence on the incidence and risk factors for EVD-related infection.

Methods

PubMed, Embase, and the Cochrane Library databases from database inception to February 28, 2022, were searched for all studies investigating the incidence and risk factors for EVD-related infection. Data were assessed by R-4.2.0 software. The meta-analysis was used to calculate pooled odds ratios (OR) and 95% confidence intervals (CI).

Results

A total of 48 studies were included. Among the 29 factors analyzed, statistically significant risk factors were subarachnoid hemorrhage(SAH)/intraventricular hemorrhage(IVH) (OR = 1.48, 95% CI = 1.20-1.82, p < 0.001), concomitant systemic infection (OR = 1.90, 95% CI = 1.34-2.70, p < 0.001), other neurosurgical procedures (OR = 1.76, 95% CI = 1.02-3.04, p = 0.041), change of catheter (OR = 5.05, 95% CI = 3.67-6.96, p < 0.001), bilateral EVDs (OR = 2.25, 95% CI = 1.03-4.89, p = 0.041), (cerebrospinal fluid) CSF leak (OR = 3.19, 95% CI = 2.12-4.81, p < 0.001) and duration of EVD >7 days (OR = 4.62, 95% CI = 2.26-9.43, p < 0.001). The use of silver-coated catheters (OR = 0.57, 95% CI = 0.38-0.87, p = 0.008) and antibiotic-impregnated catheters (OR = 0.60, 95% CI = 0.41-0.88, p = 0.009) might help reduce the risk of infection. No significant difference was indicated in studies evaluating factors like diabetes mellitus (OR = 1.25, 95% CI = 0.90-1.75, p = 0.178), steroids used (OR = 1.52, 95% CI = 0.96-2.4, p = 0.074), prophylactic antibiotics(OR = 0.87, 95% CI = 0.66-1.14, p = 0.308).

Discussion

The meta-analysis of various relevant factors in the onset of EVD-related infection in patients submitted to EVD enabled us to establish a more probable profile of the patients who are more likely to develop it during the treatment.

Treatment of Ventriculitis and Meningitis After Neurosurgery Caused by Carbapenem-Resistant Enterobacteriaceae (CRE): A Challenging Topic

Post-neurosurgical infection is a common complication of neurosurgery, and serious infection can threaten the life of patients. In recent years, the increase in multidrug-resistant bacteria, especially carbapenem-resistant Enterobacteriaceae (CRE), has proved fatal to patients. Although there are a few cases of CRE meningitis and few clinical trials have been carried out, it has attracted increasing attention with the increasing probability of its occurrence, especially considering that there are few successful cases. An increasing number of studies are also looking for the risk factors and clinical symptoms of CRE intracranial infection. In terms of treatment, some new antibiotics are gradually being used in the clinic, but due to the complicated drug-resistant mechanism of CRE and the obstruction of the blood‒brain barrier (BBB), the therapeutic effect is still very poor. In addition, obstructive hydrocephalus and brain abscess caused by CRE meningitis are still important causes of patient death and are also difficult to treat.

Postprocedural Complications of External Ventricular Drains: A Meta-Analysis Evaluating the Absolute Risk of Hemorrhages, Infections, and Revisions

BACKGROUND

External ventricular drain (EVD) insertion is often a lifesaving procedure frequently used in neurosurgical emergencies. It is routinely done at the bedside in the neurocritical care unit or in the emergency room. However, there are infectious and noninfectious complications associated with this procedure. This meta-analysis sought to evaluate the absolute risk associated with EVD hemorrhages, infections, and revisions. The secondary purpose was to identify and characterize risk factors for EVD complications.

METHODS

We searched the MEDLINE (PubMed) database for "external ventricular drain," "external ventricular drain" + "complications" or "Hemorrhage" or "Infection" or "Revision" irrespective of publication year. Estimates from individual studies were combined using a random effects model, and 95% confidence intervals (CIs) were calculated with maximum likelihood specification. To investigate heterogeneity, the t2 and I2 tests were utilized. To evaluate for publication bias, a funnel plot was developed.

RESULTS

There were 260 total studies screened from our PubMed literature database search, with 176 studies selected for full-text review, and all of these 176 studies were included in the meta-analysis as they met the inclusion criteria. A total of 132,128 EVD insertions were reported, with a total of 130,609 participants having at least one EVD inserted. The pooled absolute risk (risk difference) and percentage of the total variability due to true heterogeneity (I2) for hemorrhagic complication was 1236/10,203 (risk difference: -0.63; 95% CI: -0.66 to -0.60; I2: 97.8%), infectious complication was 7278/125,909 (risk difference: -0.65; 95% CI: -0.67 to -0.64; I2: 99.7%), and EVD revision was 674/4416 (risk difference: -0.58; 95% CI: -0.65 to -0.51; I2: 98.5%). On funnel plot analysis, we had a variety of symmetrical plots, and asymmetrical plots, suggesting no bias in larger studies, and the lack of positive effects/methodological quality in smaller studies.

CONCLUSIONS

In conclusion, these findings provide valuable information regarding the safety of one of the most important and most common neurosurgical procedures, EVD insertion. Implementing best-practice standards is recommended in order to reduce EVD-related complications. There is a need for more in-depth research into the independent risk factors associated with these complications, as well as confirmation of these findings by well-structured prospective studies.

Plasma Inflammatory Markers and Ventriculostomy-Related Infection in Patients With Hemorrhagic Stroke: A Retrospective and Descriptive Study

Background

Diagnosis of ventriculostomy-related infection (VRI) remains difficult due to the various existing definitions. In patients with hemorrhagic stroke, its diagnosis might be further complicated by the presence of intraventricular blood. Furthermore, hemorrhagic stroke per se may cause symptoms compatible with VRI. This study aimed to evaluate the benefit of plasma inflammatory markers for the diagnosis of VRI and its differentiation from patients with non-cerebral infection and patients without infection in a cohort of patients with hemorrhagic stroke.

Methods

A total of 329 patients with hemorrhagic stroke and an external ventricular drain (EVD) in situ were admitted to the Neurocritical Care Unit, University Hospital Zurich over a period of 6 years. Of those patients, 187 with subarachnoid hemorrhage and 76 with spontaneous intracerebral hemorrhage were included. Patients with VRI were compared to patients without any infection and to patients with non-cerebral infection, with regards to their clinical characteristics, as well as their inflammatory plasma and cerebrospinal fluid (CSF) markers. For the analysis, peak values were considered.

Results

The VRI was diagnosed in 36% of patients with subarachnoid and in 17% of patients with intracerebral hemorrhage. The VRI was diagnosed on an average day 9±6.2 after EVD insertion, one day after the white blood cell count (WBC) peaked in CSF (8 ± 6.3). Plasma inflammatory markers (WBC, C-reactive protein “CRP” and procalcitonin “PCT”) did not differ among patients with VRI compared to patients without infection. The CRP and PCT, however, were higher in patients with non-cerebral infection than in patients with VRI. The WBC in CSF was generally higher in patients with VRI compared to both patients without any infection and patients with non-cerebral infection.

Conclusions

No differences in plasma inflammatory markers could be found between patients with VRI and patients without any infection. Conversely, CRP/PCT were higher in patients with non-cerebral infection than in patients with VRI. Altogether, CRP, PCT, and WBC are not suitable parameters for VRI diagnosis in neurocritical care unit patients.

Effect of External Ventricular Drain Tunnel Length on Cerebrospinal Fluid Infection Rates-A Bayesian Network Meta-Analysis

BACKGROUND

External ventricular drain (EVD)-associated cerebrospinal fluid infection (EACI) remains a major complication associated with EVD. Length of EVD tunnel, an overlooked but modifiable factor, can be associated with increased risk of EACI. The aim of this study is to find the tunnel length associated with least chances of EACI by performing a network meta-analysis.

METHODS

A comprehensive search of different databases was performed to retrieve studies that studied the rates of EACI with different EVD tunnel lengths and a Bayesian network meta-analysis was performed.

RESULTS

Six studies met the inclusion criteria and were included in the network meta-analysis. With 0 cm tunnel length as reference, the odds ratio (OR) for developing EACI was minimum for tunnel length 5-10 cm (OR, 0.027). It was followed by tunnel length of 5 cm (OR, 0.060) and 10 cm (OR, 0.075). The surface under the cumulative ranking curve plot showed that the probability of the tunnel length 5-10 cm (ranked first), 5 cm (ranked second), and 10 cm (ranked third) for being the best EVD tunnel length was found to be 86%, 64%, and 61%, respectively.

CONCLUSIONS

The length for which an EVD is tunneled may have an impact on the rate of EACI. Our network meta-analyses showed that the tunnel length of 5-10 cm was associated with the lowest rates of EACI, with 86% probability of being the best EVD tunnel length. The probability of a patient with 5-10 cm EVD length developing EACI was 2.7% compared with zero tunnel length.

Securing CSF catheters to the skin: from sutures and bolt system to subcutaneous anchoring device towards zero complications

INTRODUCTION

Securing the catheter to the skin either with sutures or staples and to the skull with bolt system still represents the most common options in the management of CSF external drainage. However, these options bear an unavoidable risk of complications. This problem is common to vascular accesses and has been successfully overcome with the introduction of device for subcutaneous anchoring (SecurAcath®, Interrad Medical, Inc., Plymouth, Minnesota), which has rapidly become the standard of care in this field.

METHODS

We report our experience with the use of SecurAcath® to secure CSF drainage, either ventricular or spinal. Results were compared with literature data.

RESULTS

Since 2015, SecurAcath® was used in 209 patients (mean age 7 years) to secure 195 external cranial catheters (either ventricular or subdural or intralesional) and 16 spinal drainages. Indwell time ranged from 5 to 30 days. No complication related to the use of the device was observed. In particular, there was no case of dislocation or accidental pullout of the catheter. Rate of infection, or superinfection in case of ventricular catheter implanted for CSF infection, was null.

CONCLUSIONS

SecurAcath® is a safe and effective device to secure CSF external catheters, with several relevant advantages, including easy placement and maintenance. Moreover, it may stay in place for the whole duration of the catheter without any skin tissue trauma and allows a complete antisepsis of the exit site, thus reducing local skin complications. This factor has significant impact on the reduction of infection rate of external CSF catheters.

Surveillance of external ventricular drainage-associated meningitis and ventriculitis in German intensive care units

OBJECTIVE

In light of the infection risk associated with external ventricular drainage (EVD), we decided to establish the surveillance of EVD-associated meningitis/ventriculitis in German intensive care units (ICUs) in the framework of the German national nosocomial infection surveillance system (KISS). Here, we present the current reference data and subsequent risk-factor analysis for EVD-associated meningitis/ventriculitis rates.

METHODS

The surveillance method corresponds with the surveillance methods for device-associated infections recommended by the National Healthcare Safety Network (NHSN). All ICUs participating for at least 1 month from 2008 to 2016 in the module ICU-KISS were included in the reference dataset and the multivariate analysis.

RESULTS

Current reference data (2008-2016) are based on input from 157 ICUs. The mean EVD-associated meningitis/ventriculitis rate per 1,000 EVD days was 3.96, with little variation between neurosurgical, surgical, interdisciplinary (hospitals with >400 beds), and neurological ICUs. In total, 893 EVD-associated meningitis/ventriculitis cases and 225,351 EVD days were included in the risk-factor analysis. After multivariate analysis, 2 factors remained significant: (1) stay in an ICU labeled other than neurosurgical, surgical, interdisciplinary (>400 beds), and neurological as a protective factor and (2) EVD utilization rate above the 75th quantile as a risk factor for acquisition of EVD-associated meningitis/ventriculitis.

CONCLUSIONS

EVD-associated meningitis and ventriculitis are frequent complications of care in intensive care patients at risk. A long hospital stay and/or the presence of the EVD puts the patient at high risk for pathogen acquisition with subsequent infection.

Peripheral white blood cell count as a screening tool for ventriculostomy-related infections

One of the most common complications following external ventricular drain (EVD) placement is infection. Routine cultures of cerebrospinal fluid (CSF) are often used to screen for infection, however several days may pass before infection is discovered. In this study, we compared the predictive value of daily recorded vital sign parameters and peripheral white blood count (WBC) in identifying ventriculostomy-related infections. Patients with EVDs who had CSF cultures for microorganisms performed between January 2011 and July 2017 were assigned to either an infected and/or uninfected study group. Clinical parameters were then compared using t-test, chi squared and multiple logistic regression analyses. Patients of any age and gender were included. One hundred seventy uninfected and 10 infected subjects were included in the study. Nine of the 10 infected patients had an elevated WBC (>10.4 × 10³/μL), with a significantly greater WBC (15.9 × 10³/μL) than the uninfected group (10.4 × 10³/μL) (p-value ≤ 0.0001). Using logistic regression, we found no association between patient vital signs and CSF infection except for WBC (p = .003). As a diagnostic marker for CSF infection, the sensitivity and specificity of WBC elevation greater than 15 × 10³/μL was 70% (7/10) and 90.2% (147/163), respectively. This study serves as a 'proof of concept' that WBC could be useful as potential screening tool for early detection of CSF infection post-EVD placement. Future investigation using a large, multicenter prospective study is needed to further assess the applicability of this parameter.

Prospective, multicentre study of external ventricular drainage-related infections in the UK and Ireland

OBJECTIVES

External ventricular drain (EVD) insertion is a common neurosurgical procedure. EVD-related infection (ERI) is a major complication that can lead to morbidity and mortality. In this study, we aimed to establish a national ERI rate in the UK and Ireland and determine key factors influencing the infection risk.

METHODS

A prospective multicentre cohort study of EVD insertions in 21 neurosurgical units was performed over 6 months. The primary outcome measure was 30-day ERI. A Cox regression model was used for multivariate analysis to calculate HR.

RESULTS

A total of 495 EVD catheters were inserted into 452 patients with EVDs remaining in situ for 4700 days (median 8 days; IQR 4-13). Of the catheters inserted, 188 (38%) were antibiotic-impregnated, 161 (32.5%) were plain and 146 (29.5%) were silver-bearing. A total of 46 ERIs occurred giving an infection risk of 9.3%. Cox regression analysis demonstrated that factors independently associated with increased infection risk included duration of EVD placement for ≥8 days (HR=2.47 (1.12-5.45); p=0.03), regular sampling (daily sampling (HR=4.73 (1.28-17.42), p=0.02) and alternate day sampling (HR=5.28 (2.25-12.38); p<0.01). There was no association between catheter type or tunnelling distance and ERI.

CONCLUSIONS

In the UK and Ireland, the ERI rate was 9.3% during the study period. The study demonstrated that EVDs left in situ for ≥8 days and those sampled more frequently were associated with a higher risk of infection. Importantly, the study showed no significant difference in ERI risk between different catheter types.