Clinical review: Efficacy of antimicrobial-impregnated catheters in external ventricular drainage - a systematic review and meta-analysis

External ventricular drainage in pediatric patients: indications, management, and shunt conversion rates

PURPOSE

Placement of an external ventricular drainage (EVD) is one of the most frequent procedures in neurosurgery, but it has specific challenges and risks in the pediatric population. We here investigate the indications, management, and shunt conversion rates of an EVD.

METHODS

We retrospectively analyzed the data of a consecutive series of pediatric patients who had an EVD placement in the Department of Neurosurgery at Hannover Medical School over a 12-year period. A bundle approach was introduced to reduce infections. Patients were categorized according to the underlying pathology in three groups: tumor, hemorrhage, and infection.

RESULTS

A total of 126 patients were included in this study. Seventy-two were male, and 54 were female. The mean age at the time of EVD placement was 5.2 ± 5.0 years (range 0-17 years). The largest subgroup was the tumor group (n = 54, 42.9%), followed by the infection group (n = 47, 37.3%), including shunt infection (n = 36), infected Rickham reservoir (n = 4), and bacterial or viral cerebral infection (n = 7), and the hemorrhage group (n = 25, 19.8%). The overall complication rate was 19.8% (n = 25/126), and the total number of complications was 30. Complications during EVD placement were noted in 5/126 (4%) instances. Complications during drainage time were infection in 9.5% (12 patients), dysfunction in 7.1% (9 patients), and EVD dislocation in 3.2% (4 patients). The highest rate of complications was seen in the hemorrhage group. There were no long-term complications. Conversion rates into a permanent shunt system were 100% in previously shunt-dependent patients. Conversion rates were comparable in the tumor group (27.7%) and in the hemorrhage group (32.0%).

CONCLUSION

EVD placement in children is an overall safe and effective option in children. In order to make further progress, carefully planned prospective and if possible randomized studies are needed controlling for multivariable aspects.

Treatment of Intraventricular Hemorrhage with External Ventricular Drainage and Fibrinolysis: A Comprehensive Systematic Review and Meta-Analysis of Complications and Outcome

BACKGROUND

External ventricular drainage (EVD) is a key factor in the treatment of intraventricular hemorrhage (IVH) but associated with risks and complications. Intraventricular fibrinolysis (IVF) has been proposed to improve clinical outcome and reduce complications of EVD treatment. The following review and metaanalysis provides a comprehensive evaluation of IVH treatment with external ventricular drainage (EVD) and intraventricular fibrinolysis (IVF) with regards to complications and clinical outcomes.

METHODS

The PRISMA guidelines were followed preparing this review. Studies included in the meta-analysis were compared using forest plots and the related odds ratios.

RESULTS

After a literature search, 980 articles were identified and 65 and underwent full-text review. Forty-two articles were included in the review and meta-analysis. We found that bolted and antibiotic-coated catheters were superior to tunnelled/uncoated catheters (P < 0.001) and antibiotic- vs. silver-impregnated catheters (P < 0.001]) in preventing infection. Shunt dependency was related to the volume of blood in the ventricles but unaffected by IVF (P = 0.98). IVF promoted hematoma clearance, decreased mortality (22.4% vs. 40.9% with IVF vs. no IVF, respectively, P < 0.00001), improved good functional outcomes (47.2% [IVF] vs. 38.3% [no IVF], P = 0.03), and reduced the rate of catheter occlusion from 37.3% without IVF to 10.6% with IVF (P = 0.0003).

CONCLUSIONS

We present evidence and best practice recommendations for the treatment of IVH with EVD and intraventricular fibrinolysis. Our analysis further provides a comprehensive quantitative reference of the most relevant clinical endpoints for future studies on novel IVH technologies and treatments.

Prevention of Ventriculostomy Related Infection: Effectiveness of Impregnated Biomaterial

External ventricular drain(EVD) exposes the patient to infectious complications which are associated with significant morbidity and economic burden. Biomaterials impregnated with various antimicrobial agents have been developed to decrease the rate of bacterial colonization and subsequent infection. While promising, antibiotics and silver-impregnated EVD showed conflicting clinical results. The aim of the present review is to discuss the challenges associated with the development of antimicrobial EVD catheters and their effectiveness from the bench to the bedside.

Risk factors and outcomes associated with external ventricular drain infections

BACKGROUND

Insertion of an external ventricular drain (EVD) is a common neurosurgical procedure which may lead to serious complications including infection. Some risk factors associated with EVD infection are well established. Others remain less certain, including specific indications for placement, prior neurosurgery, and prior EVD placement.

OBJECTIVE

To identify risk factors for EVD infections.

METHODS

We reviewed all EVD insertions at our institution from March 2015 through May 2019 following implementation of a standardized infection control protocol for EVD insertion and maintenance. Cox regression was used to identify risk factors for EVD infections.

RESULTS

479 EVDs placed in 409 patients met inclusion criteria, and 9 culture-positive infections were observed during the study period. The risk of infection within 30 days of EVD placement was 2.2% (2.3 infections/1,000 EVD days). Coagulase-negative staphylococci were identified in 6 of the 9 EVD infections). EVD infection led to prolonged length of stay post-EVD-placement (23 days vs 16 days; P = .045). Cox regression demonstrated increased infection risk in patients with prior brain surgery associated with cerebrospinal fluid (CSF) diversion (HR, 8.08; 95% CI, 1.7-39.4; P = .010), CSF leak around the catheter (HR, 21.0; 95% CI, 7.0-145.1; P = .0007), and insertion site dehiscence (HR, 7.53; 95% CI, 1.04-37.1; P = .0407). Duration of EVD use >7 days was not associated with infection risk (HR, 0.62; 95% CI, 0.07-5.45; P = .669).

CONCLUSION

Risk factors associated with EVD infection include prior brain surgery, CSF leak, and insertion site dehiscence. We found no significant association between infection risk and duration of EVD placement.

The Use of Intraventricular Instillation of Vancomycin to Prevent External Ventricular Drainage Related Infection: A Clinical Prospective Study

BACKGROUND

External ventricular drainage (EVD)-related infection (ERI) represents an important condition with potential high morbidity with significant impact on patient outcomes. Prophylactic systemic antibiotics are routinely administered to patients with EVD, but they do not significantly lower the incidence of ERIs. Intraventricular treatment with vancomycin appeared to be safe and effective, but most reports are case-reports/-series and retrospective studies.

METHODS

A prospective non-randomized case-control study was conducted in a consecutive series of 116 patients treated with EVD insertion. The study includes the group of patients treated with intrathecal vancomycin (Group A, 62 patients) compared with the control group treated with daily intravenous cefazolin (Group B, 54 patients).

RESULTS

No statistically significant differences were found between the 2 groups with regard to the duration of catheterization and occurrence of ERI during hospitalization. EVD was replaced in 16 cases (25.8%) in group A and in 12 cases (22.2%) in the control group B (P 0.67). Three cases (4.8%) of ERI have been found in group A and 5 (9.3%) in the control group (P = 0.34). All reported cases of infection in group A were caused by gram-negative agents; on the opposite, cases of infections in the control group B were caused above all by gram-positive bacteria with a statistical difference (P = 0.03).

CONCLUSIONS

In this first prospective study on this topic, we found that intrathecal Vancomycin administration in EVDs does not reduce the occurrence of ERI compared with intravenous cefazolin prophylaxis, but induces selection of gram-negative bacteria.

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.

Antibiotic Prophylaxis and Incidence of Infection with External Ventricular Drains and Intra-Cranial Pressure Monitors

Objectives: Guidelines do not recommend extended antibiotic prophylaxis for external ventricular drains (EVD) or intra-cranial pressure (ICP) monitors. The study objective was to determine if infection rates are different for patients receiving antibiotic prophylaxis for EVD or ICP monitors. Patients and Methods: This single-center retrospective cohort reviewed intensive care unit patients who had an EVD or ICP monitor placed. Patients receiving antibiotic prophylaxis were compared with those who did not receive prophylaxis. The primary end point was incidence of central nervous system (CNS) infection. Results: Overall, 228 patients were included, 120 of whom received prophylaxis and 108 who did not receive prophylaxis. The primary end point of CNS infection was not different between groups (18 [17%] vs. 23 [19%]; p = 0.6236). Conclusions: Antibiotic prophylaxis was not associated with a decreased incidence of CNS infection in patients with EVD or ICP monitors. Evaluation of antibiotic use in this patient population is warranted to prevent resistance and adverse drug effects.

Current Perspectives on the Diagnosis and Management of Healthcare-Associated Ventriculitis and Meningitis

Ventriculitis or post-neurosurgical meningitis or healthcare-associated ventriculitis and meningitis (VM) is a severe infection that complicates central nervous system operations or is related to the use of neurosurgical devices or drainage catheters. It can further deteriorate patients who have already presented significant neurologic injury and is associated with high morbidity, mortality, and poor functional outcome. VM can be difficult to distinguish from aseptic meningitis, inflammation that follows hemorrhagic strokes and neurosurgical operations. The associated microorganisms can be either skin flora or nosocomial pathogens, most commonly, Gram-negative bacteria. Classical microbiology can fail to isolate the culprit pathogen. Novel cerebrospinal fluid (CSF) biomarkers and molecular microbiology can fill the diagnostic gap and expedite pathogen identification and treatment. The pathogens may demonstrate significant resistant patterns and their antibiotic treatment can be difficult, as many important drug classes, including the beta-lactams and the glycopeptides, hardly penetrate to the CSF, and do not achieve therapeutic levels at the site of the infection. Treatment modifications, such as higher daily dose and prolonged or continuous administration, might increase antibiotic levels in the site of infection and facilitate pathogens clearance. However, in the case of therapeutic failure or infection due to difficult-to-treat bacteria, the direct antibiotic instillation into the CSF, in addition to the intravenous antibiotic delivery, may help in the resolution of infection. However, intraventricular antibiotic therapy may result in aseptic meningitis and seizures, concerning the administration of aminoglycosides, polymyxins, and vancomycin. Meanwhile, bacteria form biofilms on the catheter or the device that should routinely be removed. Novel neurosurgical treatment modalities comprise endoscopic evacuation of debris and irrigation of the ventricles. VM prevention includes perioperative antibiotics, antimicrobial impregnated catheters, and the implementation of standardized protocols, regarding catheter insertion and manipulation.

Ventriculitis: Infection or Inflammation

Ventriculitis, or infection of the cerebrospinal fluid, in the presence of external ventricular drains (EVD), is an important complication and associated with substantial mortality, morbidity, and healthcare costs. Further, the conditions that require the insertion of an EVD, such as neurotrauma and subarachnoid hemorrhage, are themselves associated with inflammation of the cerebrospinal fluid. Phenotypically, patients with inflammation of the cerebrospinal fluid can present with very similar symptoms, signs, and laboratory findings to those with infection. This review examines various controversies relating to the definitions, diagnosis, challenges of differentiating infection from inflammation, prevention, and treatment of ventriculitis in patients with EVDs.

Use of emerging technologies to enhance the treatment paradigm for spontaneous intraventricular hemorrhage

The presence of intraventricular hemorrhage (IVH) portends a worse prognosis in patients presenting with spontaneous intracerebral hemorrhage (ICH). Intraventricular hemorrhage increases the rates of hydrocephalus, ventriculitis, and long-term shunt dependence. Over the past decade, novel medical devices and protocols have emerged to directly treat IVH. Presently, we review new technological adaptations to treating intraventricular hemorrhage in an effort to focus further innovation in treating this morbid neurosurgical pathology. We summarize current and historical treatments as well as innovations in IVH including novel procedural techniques, use of the Integra Surgiscope, use of the Artemis evacuator, use of BrainPath, novel catheter technology, large bore external ventricular drains, the IRRAflow, the CerebroFlo, and the future directions of the field. Technology and medical devices for both surgical and nonsurgical methods are advancing the treatment of IVH. With many promising new technologies on the horizon, prospects for improved clinical care for IVH and its etiologies remain hopeful.

Decreasing External Ventricular Drain Infection Rates in the Neurocritical Care Unit: 12-Year Longitudinal Experience at a Single Institution

OBJECTIVE

External ventricular drain (EVD) placement is a common neurosurgical procedure, and EVD-related infection is a significant complication. We examined the effect of infection control protocol changes on EVD-related infection incidence.

METHODS

Changes in EVD placement protocol and incidence density of infections after implementation of protocol changes in the neurocritical care unit were tracked from 2007 to 2019. EVD infections were defined using a modified U.S. Centers for Disease Control and Prevention National Healthcare Safety Network surveillance definition of meningitis/ventriculitis for patients with EVDs in situ for at least 2 days confirmed by positive culture. Contribution of protocol changes to EVD infection risk was assessed via multivariate regression.

RESULTS

Fifteen major changes in EVD protocol were associated with a reduction in infections from 6.7 to 2.0 per 1000 EVD days (95% confidence interval [CI], 4.1-5.3; P < 0.001). Gram-positive bacterial infection incidence decreased from 4.8 to 1.7 per 1000 EVD days (95% CI, 2.3-3.9; P = 0.00882) and gram-negative infection incidence decreased from 1.9 to 0.5 per 1000 EVD days (95% CI, 0.6-2.3; P = 0.0303). Of all protocol changes since 2007, the largest reduction in incidence was 3.9 infections per 1000 days (95% CI, 0.50-7.30; P = 0.011), associated with combined standardization of reduced EVD sampling frequency, cutaneous antisepsis with alcoholic chlorhexidine before EVD placement, and use of a subcutaneous tunneling technique during EVD insertion.

CONCLUSIONS

The most significant reduction in EVD infections may be achieved through the combination of reducing EVD sampling frequency and standardizing alcoholic chlorhexidine cutaneous antisepsis and subcutaneous tunneling of the EVD catheter.

Antibiotic-Eluting Envelopes to Prevent Cardiac-Implantable Electronic Device Infection: Past, Present, and Future

Objective: Cardiac-implantable electronic device (CIED) infections are associated with significant morbidity and mortality. In this review, we describe the risk factors and pathogenesis of CIED infections and review the rationale and the evidence for the use of antibiotic-eluting envelopes (ABEs) in patients at increased risk for CIED infections.

Findings: The majority of CIED infections are caused by staphylococci that involve generator pocket and occur due to contamination of the device or the pocket tissues at the time of implantation. Clinical trials have shown that extending the duration of post-operative systemic antibacterial therapy is not beneficial in reducing CIED infection rate. However, ABEs that reduce device migration after implantation and provide sustained local delivery of prophylactic antibiotics at the pocket site, may provide benefit in reducing infection. Currently, there are two types of commercially available CIED envelope devices in the United States. The first ABE device (TYRX™, Medtronic Inc., Monmouth Junction, NJ) is composed of a synthetic absorbable mesh envelope that elutes minocycline and rifampin and has been shown to reduce CIED pocket infections in a large multi-center randomized clinical trial. The second ABE device (CanGaroo-G™, Aziyo Biologics, Silver Spring, MD) is composed of decellularized extracellular matrix (ECM) and was originally designed to stabilize the device within the pocket, limiting risk for migration or erosion, and providing a substrate for tissue ingrowth in a preclinical study. This device has shown promising results in a preclinical study with local delivery of gentamicin. Compared with artificial materials, such as synthetic surgical mesh, biologic ECM has been shown to foster greater tissue integration and vascular ingrowth, a reduced inflammatory response, and more rapid clearance of bacteria.

Conclusions and Relevance: ABE devices provide sustained local delivery of antibiotics at the generator pocket site and appear beneficial in reducing CIED pocket infections. Given the continued increase in the use of CIED therapy and resultant infectious complications, innovative approaches to infection prevention are critical.

Prevention of surgical site infections after brain surgery: the prehistoric period to the present

In this historical vignette, the authors discuss the prevention of surgical site infections (SSIs) after brain surgery from the prehistoric period to the present. Although the mechanism for infection was not fully understood until the 19th century, records demonstrate that as early as 10,000 bc, practitioners used gold, a biocidal material, for cranioplasties and attempted to approximate wounds by tying a patient's hair across the incision. Written records from the Egyptian and Babylonian period depict the process of soaking head dressings in alcohol, an antibacterial agent. In the Greek and Early Byzantine period, Hippocrates argued against the formation of pus in wounds and continued to champion the use of wine in wound management. In the 16th century, intracranial silver drains were first utilized in an effort to prevent postoperative infections. The turning point of SSI prevention was in 1867, when Joseph Lister illustrated the connection between Louis Pasteur's discovery of the fermentation process and the suppuration of wounds. Today, there are ongoing investigations and debates about the optimal techniques to prevent SSI after brain surgery. Although tremendous progress in the field of SSI prevention since the prehistoric period has been made, SSI continues to affect morbidity and mortality after brain surgery.

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.

Decompressive craniectomy for acute ischemic stroke

Malignant stroke occurs in a subgroup of patients suffering from ischemic cerebral infarction and is characterized by neurological deterioration due to progressive edema, raised intracranial pressure, and cerebral herniation. Decompressive craniectomy (DC) is a surgical technique aiming to open the “closed box” represented by the non-expandable skull in cases of refractory intracranial hypertension. It is a valuable modality in the armamentarium to treat patients with malignant stroke: the life-saving effect has been proven for both supratentorial and infratentorial DC in virtually all age groups. This leaves physicians with the difficult task to decide who will require early or preemptive surgery and who might benefit from postponing surgery until clear evidence of deterioration evolves. Together with the patient’s relatives, physicians also have to ascertain whether the patient will have acceptable disability and quality of life in his or her presumed perception, based on preoperative predictions. This complex decision-making process can only be managed with interdisciplinary efforts and should be supported by continued research in the age of personalized medicine.

Improving Ventriculostomy Management: Risk and Cost Reduction Through a Multidisciplinary Approach

OBJECTIVE

Infection is a life-threatening complication of ventriculostomy. The purpose of this quality improvement project was to develop a cost-effective, evidence-based intervention to reduce ventriculostomy-associated infection (VAI) rates.

METHODS

In this retrospective study, patients undergoing ventriculostomy insertion between June 2008 and December 2016 were identified, and charts were reviewed. The study period between June 2008 and August 2010 constituted the baseline (phase 1) in which non-antibiotic-coated ventriculostomy catheters were used and cerebrospinal fluid (CSF) sampling was done daily. Then, 2 sequential interventions were implemented. Between September 2010 and January 2013, antibiotic-coated ventriculostomy catheters (AC-Vs) were used (phase 2). Then, between February 2013 and December 2016, the frequency of CSF sampling was minimized to twice a week (phase 3). The rates of VAI and operational costs, or cost incurred for the external ventricular drain catheter, antibiotics, laboratory analysis, and CSF sampling supplies, were compared for each phase.

RESULTS

The average infection rate for phase 1 was 3.3 infections per 1000 device-days. The VAI rates for phases 2 and 3 were 1.6 and 0.8, respectively. The use of AC-Vs and reduced CSF sampling resulted in a VAI rate decrease of 75.8% (P = 0.01). During 2014, there were no VAIs. The intervention produced an estimated $1.02 million in savings for the institution during phase 3. The average projected savings of this intervention was $175 per patient per day and reduced cost by 72%.

CONCLUSIONS

The use of AC-Vs in combination with decreased frequency of CSF sampling was cost saving and resulted in a significant reduction in device-related infections.

Retrospective Analysis of Ventriculitis in External Ventricular Drains

Background

Nosocomial EVD-related ventriculitis is a major complication and a significant cause of morbidity and mortality in critically ill neurological patients. Questions remain about best management of EVDs. The purpose of this study is to compare our incidence of ventriculitis to studies using different catheters and/or antibiotic coverage schemes and determine whether c-EVD with prolonged antibiotics given for the duration of drain placement is inferior to ac-EVD with pp-abx or ac-EVD with prolonged antibiotics for prevention of ventriculitis.

Methods

A retrospective chart review of all patients who had EVDs placed from January 2010 through December 2015 at home institution was performed. Statistical analysis was performed using Fisher's exact test to compare incidence of ventriculitis identified in other studies with that of home institution.

Results

The study included 107 patients, 66 (61.7%) males and 41 (38.3%) females. Average age was 56 years ranging from 18 to 95 years. Average length of drain placement was 7.8 days ranging from 2 to 23 days. Average length of drain placement in infected drains was 13.3 days ranging from 11 to 15 days. There were 3 cases with positive CSF cultures (Staphylococcus haemolyticus and Staphylococcus epidermidis x 2). There were 2 cases with a CSF having a positive gram stain but failed to yield any bacterial growth on culture and did not meet predefined criteria.

Conclusions

The c-EVD with prolonged antibiotics given for the duration of drain placement is not inferior to ac-EVD with pp-abx or ac-EVD with prolonged antibiotics for prevention of ventriculitis. The c-EVD with prolonged antibiotics is superior to c-EVD with pp-abx and conventional EVD without antibiotics for prevention of ventriculitis. Selection should include considerations for antibiotic stewardship and cost effectiveness. Future studies should also utilize clinical and CSF profile criteria in addition to positive CSF cultures for identifying ventriculitis to prevent line colonization from classification as ventriculitis in analysis.

The SiLuDrain Trial: a prospective randomized controlled trial comparing standard versus silver-impregnated lumbar drains

OBJECTIVE

Catheter-associated cerebrospinal fluid (CSF) infection remains a serious event, especially for patients in neurocritical care units. The use of external ventricular drain (EVD) catheters impregnated with antimicrobial substances has led to a significant reduction of infection rates. This study was undertaken to compare the use of antimicrobial, silver-impregnated external lumbar drains (si-ELDs) and conventional ELDs.

METHODS

Patients with an indication for ELD placement were randomized to receive either a conventional or an si-ELD catheter. Regular assessment for CSF infections and device-related complications was performed. Neurosurgeons placing the ELD rated the usability and handling of the catheter on a 6-item ordinal performance scale (range: 1, very bad, to 5, very good). All microorganisms isolated in this study were tested for silver-susceptibility via a catheter-roll method.

RESULTS

A total of 48 patients were enrolled in the trial. The si-ELD catheters showed a nonsignificantly lower infection rate compared to conventional ones (4.2% vs 16.7%, p = 0.16). The majority of infections were caused by Staphylococcus species. Device-related complications occurred significantly less often with silver-impregnated-catheters than with conventional ones (8.3% vs 37.5%, p = 0.02). The usability was rated significantly better for si-ELDs (p = 0.003). Antimicrobial susceptibility was shown for si-ELDs against various Staphylococcus spp., but Candida parapsilosis and Escherichia coli were not affected by this antimicrobial agent.

CONCLUSIONS

Silver-impregnated ELD catheters, which could potentially reduce the number of CSF infections, show significantly better properties in regard to handling and fewer device-related complications. Whether they are superior to antibiotic-impregnated catheters or a clinical regimen involving antibiotic prophylaxis remains to be proven.Clinical trial registration no.: DRKS00013513 (Deutsches Register Klinischer Studien).

Management of traumatic brain injury patients

Traumatic brain injury (TBI) has been called the ‘silent epidemic’ of modern times, and is the leading cause of mortality and morbidity in children and young adults in both developed and developing nations worldwide. In recent years, the treatment of TBI has undergone a paradigm shift. The management of severe TBI is ideally based on protocol-based guidelines provided by the Brain Trauma Foundation. The aims and objectives of its management are prophylaxis and prompt management of intracranial hypertension and secondary brain injury, maintenance of cerebral perfusion pressure, and ensuring adequate oxygen delivery to injured brain tissue. In this review, the authors discuss protocol-based approaches to the management of severe TBI as per recent guidelines.

Prevenção da formação de biofilmes em marcapassos artificiais: é viável?

Resumo Objetivo: Identificar os agentes antimicrobianos utilizados na prevenção da formação de biofilme em marcapassos artificiais. Métodos: Revisão da literatura para responder a seguinte questão: “Quais agentes antimicrobianos são usados para prevenir a formação de biofilmes em marcapassos artificiais?” As bases de dados PubMed, Web of Science, Scopus, Science Direct, Cochrane, CINAHL, Embase e LILACS foram consultadas em todos os idiomas sem restrição de tempo. Resultados: A amostra final apresentou cinco estudos primários, sendo a maioria experimental. As investigações identificaram agentes com potencial para a redução ou inibição da formação de biofilmes em marcapassos. Destacou-se a associação de agentes físico-químicos e farmacológicos aos agentes antimicrobianos. Conclusão: A prevenção da formação de biofilmes em marcapassos é viável. Os agentes mais promissores para obter este efeito foram a rifampicina, AIGIS®, a formulação aquosa neobactrim e a cobertura com trimetilsilano e oxigênio em superfícies tratadas com plasma.

Management of Traumatic Brain Injury

Traumatic brain injury remains a serious public health problem, causing death and disability for millions. In order to maximize outcomes in the face of a complex injury to a complex organ, a variety of advanced neuromonitoring techniques may be used to guide surgical and medical decision-making. Because of the heterogeneity of injury types and the plethora of treatment confounders present in this patient population, the scientific study of specific interventions is challenging. This challenge highlights the need for a firm understanding of the anatomy and pathophysiology of brain injuries when making clinical decisions in the intensive care unit.

Variations in Strategies to Prevent Ventriculostomy-Related Infections: A Practice Survey

BACKGROUND AND PURPOSE

The ideal strategy to prevent infections in patients with external ventricular drains (EVDs) is unclear.

METHODS

We conducted a cross-sectional survey of members of the Neurocritical Care Society on infection prevention practices for patients with EVDs between April and July 2015.

RESULTS

The survey was completed by 52 individuals (5% response rate). Catheter selection, use of prolonged prophylactic systemic antibiotics (PPSAs), cerebrospinal fluid (CSF) collection policies, location of EVD placement, and performance of routine EVD exchanges varied. Antibiotic-impregnated catheters (AICs) and conventional catheters (CCs) were used with similar frequency, but no respondents reported routine use of silver-impregnated catheters (SICs). The majority of respondents were either neutral or disagreed with the need for PPSA with all catheter types (CC: 75%, AIC: 85%, and SIC: 87%). Despite this, 55% of the respondents reported PPSAs were routinely administered to patients with EVDs at their institutions. The majority (80%) of the respondents reported CSF collection only on an as-needed basis. The EVD placement was restricted to the operating room at 27% of the respondents' institutions. Only 2 respondents (4%) reported that routine EVD exchanges were performed at their institution.

CONCLUSION

Practice patterns demonstrate that institutions use varying strategies to prevent ventriculostomy-related infections. Identification and further study of optimum care for these patients are essential to decrease the risk of complications and to aid development of practice standards.

CNS infections in patients with hematological disorders (including allogeneic stem-cell transplantation)-Guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Diagnosis of CNS infections remains a great challenge in patients with hematological disorders since symptoms might both be masked and be mimicked by other conditions such as metabolic disturbances or consequences from antineoplastic treatment. Thus, awareness of this complication is crucial and any suspicion of a CNS infection should lead to timely and adequate diagnostics and treatment to improve the outcome in this population.

Infections of the central nervous system (CNS) are infrequently diagnosed in immunocompetent patients, but they do occur in a significant proportion of patients with hematological disorders. In particular, patients undergoing allogeneic hematopoietic stem-cell transplantation carry a high risk for CNS infections of up to 15%. Fungi and Toxoplasma gondii are the predominant causative agents. The diagnosis of CNS infections is based on neuroimaging, cerebrospinal fluid examination and biopsy of suspicious lesions in selected patients. However, identification of CNS infections in immunocompromised patients could represent a major challenge since metabolic disturbances, side-effects of antineoplastic or immunosuppressive drugs and CNS involvement of the underlying hematological disorder may mimic symptoms of a CNS infection. The prognosis of CNS infections is generally poor in these patients, albeit the introduction of novel substances (e.g. voriconazole) has improved the outcome in distinct patient subgroups. This guideline has been developed by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) with the contribution of a panel of 14 experts certified in internal medicine, hematology/oncology, infectious diseases, intensive care, neurology and neuroradiology. Grades of recommendation and levels of evidence were categorized by using novel criteria, as recently published by the European Society of Clinical Microbiology and Infectious Diseases.

Ventriculostomies without dressings: Low infection rates but room for quality improvement

Objective

Ventriculostomies are common procedures for patients with severe neurologic insults including trauma, aneurysmal rupture, tumor, infection or following an operation. Infection secondary to a ventriculostomy, meningitis or ventriculitis, carries a high morbidity and mortality. Insertion practices and maintenance of these interventions was evaluated.

Methods

A retrospective review was completed of patients receiving ventriculostomies at a single institution from October 2007 through September 2013. Basic patient demographics, methods of insertion and presence of infection were collected and analyzed.

Results

The mean of age of patients receiving ventriculostomies was 49 years of age and the most common indications for insertion were trauma, infection and nontraumatic intracranial hemorrhage (aneurysmal subarachnoid hemorrhage (SAH), hemorrhagic stroke, arteriovenous malformation (AVM)). External ventricular drains (EVDs) were inserted after minimal hair removal at the time of procedure, tunneling following procedure and securement of EVDs with suture at exit of skin and remainder of drain stapled to scalp without additional dressing applied. The infection rate using this practice was 5.1%.

Conclusion

Ventriculostomies with minimal hair removal and no dressing have equivalent infection rates with the most recent published national average.

International multidisciplinary consensus conference on multimodality monitoring: ICU processes of care

There is an increased focus on evaluating processes of care, particularly in the high acuity and cost environment of intensive care. Evaluation of neurocritical-specific care and evidence-based protocol implementation are needed to effectively determine optimal processes of care and effect on patient outcomes. General quality measures to evaluate intensive care unit (ICU) processes of care have been proposed; however, applicability of these measures in neurocritical care populations has not been established. A comprehensive literature search was conducted for English language articles from 1990 to August 2013. A total of 1,061 articles were reviewed, with 145 meeting criteria for inclusion in this review. Care in specialized neurocritical care units or by neurocritical teams can have a positive impact on mortality, length of stay, and in some cases, functional outcome. Similarly, implementation of evidence-based protocol-directed care can enhance outcome in the neurocritical care population. There is significant evidence to support suggested quality indicators for the general ICU population, but limited research regarding specific use in neurocritical care. Quality indices for neurocritical care have been proposed; however, additional research is needed to further validate measures.

Silver-impregnated external-ventricular-drain-related cerebrospinal fluid infections: a meta-analysis

BACKGROUND

Cerebrospinal fluid (CSF) infection is the primary complication associated with placement of an external ventricular drain (EVD). The use of silver-impregnated EVD catheters has become commonplace in many neurosurgical centres.

AIM

To assess the effect of silver-impregnated EVD catheter usage on catheter-related CSF infections.

METHODS

A meta-analysis was performed by systematically searching Medline, Embase and the Cochrane Library. All randomized controlled trials (RCTs) and non-RCTs comparing silver-impregnated and plain EVD catheters were identified and analysed.

FINDINGS

Six non-RCTs were included. The crude infection rate was 10.8% for plain catheters and 8.9% for silver-impregnated catheters [pooled odds ratio (OR) 0.71, 95% confidence interval (CI) 0.46-1.08; P = 0.11]. In a microbiological spectrum analysis, silver-impregnated catheters demonstrated a significantly lower rate of CSF infections caused by Gram-positive organisms (2.0% vs 6.7% in the silver-impregnated and plain catheter groups, respectively; pooled OR 0.27, 95% CI 0.11-0.63; P = 0.002).

CONCLUSION

The antimicrobial effects of silver-impregnated EVD catheters may be selective, and may need to be evaluated further in a prospective, controlled manner.

Nanoscale Plasma Coating Inhibits Formation of Staphylococcus aureus Biofilm

Staphylococcus aureus commonly infects medical implants or devices, with devastating consequences for the patient. The infection begins with bacterial attachment to the device, followed by bacterial multiplication over the surface of the device, generating an adherent sheet of bacteria known as a biofilm. Biofilms resist antimicrobial therapy and promote persistent infection, making management difficult to futile. Infections might be prevented by engineering the surface of the device to discourage bacterial attachment and multiplication; however, progress in this area has been limited. We have developed a novel nanoscale plasma coating technology to inhibit the formation of Staphylococcus aureus biofilms. We used monomeric trimethylsilane (TMS) and oxygen to coat the surfaces of silicone rubber, a material often used in the fabrication of implantable medical devices. By quantitative and qualitative analysis, the TMS/O2 coating significantly decreased the in vitro formation of S. aureus biofilms; it also significantly decreased in vivo biofilm formation in a mouse model of foreign-body infection. Further analysis demonstrated TMS/O2 coating significantly changed the protein adsorption, which could lead to reduced bacterial adhesion and biofilm formation. These results suggest that TMS/O2 coating can be used to effectively prevent medical implant-related infections.

Impact of antibiotic- and silver-impregnated external ventricular drains on the risk of infections: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

External ventricular drainage (EVD) is one of the most common and effective procedures in neurosurgery practice. However, catheter-related infection (CRI), which is associated with significant mortality and morbidity, plagues this procedure. We evaluated the efficacy of antibiotic-impregnated EVD (AI-EVD) and silver-impregnated EVD (SI-EVD) catheters compared with plain EVD catheters for the prevention of CRI.

METHODS

The authors performed an independent search of Medline, Embase, and the Cochrane Library to identify eligible studies published between January 2002 and August 2014. We searched all relevant literature using an exhaustive search strategy. Randomized controlled trials or observational studies that compared AI-EVD catheters with plain EVD catheters for the prevention of CRI were included. The quality of each included study was assessed using a risk of bias assessment tool and the Newcastle-Ottawa Scale. RevMan5.3 software (The Cochrane Collaboration, Oxford, UK) was used to perform this meta-analysis, and publication bias was investigated using funnel plot constructions and Egger test.

RESULTS

A total of 4 randomized and 10 observational studies involving 4,399 patients were included in this meta-analysis. Pooled results comparing AI-EVD catheters with plain EVD catheters in the management of patients with acute high intracranial pressure demonstrated the superiority of antimicrobial EVDs for the prevention of CRI with a risk induction of 62% (95% confidence interval [CI], 0.25-0.58; P < .00001). Subgroup analyses of pooled data from separate analyses of AI-EVDs and SI-EVDs showed the efficacy of both measures for CRI prevention, with a risk ratio (RR) of 0.31 (95% CI, 0.18-0.55; P < .0001) and an RR of 0.59 (95% CI, 0.40-0.88; P = .010), respectively. The protective effects of these AI-EVD catheters remained significant in the subgroup of randomized controlled trials with an RR of 0.48 (95% CI, 0.25-0.90; P = .02). A similar result was also seen after a pooled analysis of observational studies with an RR of 0.35 (95% CI, 0.21-0.60; P = .0001). The heterogeneity among studies was moderate (I(2) = 49%) and was primarily attributed to the inclusion of 1 large, positive cohort study. Publication bias was unlikely in the current meta-analysis.

CONCLUSIONS

Our restults indicate that both AI-EVDs and SI-EVDs are more effective than plain EVDs for the prevention of CRI. There is no conclusive evidence on the preference of AI-EVDs vs SI-EVDs because of insufficient data. Further well-designed, multicenter randomized controlled trials are required to confirm the findings of this meta-analysis.

Antimicrobial-impregnated and -coated shunt catheters for prevention of infections in patients with hydrocephalus: a systematic review and meta-analysis

OBJECT The aim of this study was to evaluate the effectiveness of antimicrobial-impregnated and -coated shunt catheters (antimicrobial catheters) in reducing the risk of infection in patients undergoing CSF shunting or ventricular drainage. METHODS The PubMed and Scopus databases were searched. Catheter implantation was classified as either shunting (mainly ventriculoperitoneal shunting) or ventricular drainage (mainly external [EVD]). Studies evaluating antibioticimpregnated catheters (AICs), silver-coated catheters (SCCs), and hydrogel-coated catheters (HCCs) were included. A random effects model meta-analysis was performed. RESULTS Thirty-six studies (7 randomized and 29 nonrandomized, 16,796 procedures) were included. The majority of data derive from studies on the effectiveness of AICs, followed by studies on the effectiveness of SCCs. Statistical heterogeneity was observed in several analyses. Antimicrobial shunt catheters (AICs, SCCs) were associated with lower risk for CSF catheter-associated infections than conventional catheters (CCs) (RR 0.44, 95% CI 0.35-0.56). Fewer infections developed in the patients treated with antimicrobial catheters regardless of randomization, number of participating centers, funding, shunting or ventricular drainage, definition of infections, de novo implantation, and rate of infections in the study. There was no difference regarding gram-positive bacteria, all staphylococci, coagulase-negative streptococci, and Staphylococcus aureus, when analyzed separately. On the contrary, the risk for methicillin-resistant S. aureus (MRSA, RR 2.64, 95% CI 1.26-5.51), nonstaphylococcal (RR 1.75, 95% CI 1.22-2.52), and gram-negative bacterial (RR 2.13, 95% CI 1.33-3.43) infections increased with antimicrobial shunt catheters. CONCLUSIONS Based on data mainly from nonrandomized studies, AICs and SCCs reduce the risk for infection in patients undergoing CSF shunting. Future studies should evaluate the higher risk for MRSA and gram-negative infections. Additional trials are needed to investigate the comparative effectiveness of the different types of antimicrobial catheters.

External ventricular drain infections: risk factors and outcome

External ventricular drainage (EVD) is frequently used in neurosurgery to drain cerebrospinal fluid in patients with raised intracranial pressure. We performed a retrospective single center study in order to evaluate the incidence of EVD-related infections and to identify underlying risk factors. 246 EVDs were placed in 218 patients over a 30-month period. EVD was continued in median for 7 days (range 1–44). The cumulative incidence of EVD-related infections was 8.3% (95% CI, 5.3–12.7) with a device-associated infection rate of 10.4 per 1000 drainage days (95% CI, 6.2–16.5). The pathogens most commonly identified were coagulase-negative Staphylococcus (62%) followed by Enterococcus spp. (19%). Patients with an EVD-related infection had a significantly longer ICU (11 versus 21 days, P < 0.01) and hospital stay (20 versus 28.5 days, P < 0.01) than patients without. Median total duration of external drainage was twice as long in patients with EVD-related infection (6 versus 12 days, P < 0.01). However, there was no significant difference in the duration between first EVD placement and the occurrence of EVD-related infection and EVD removal in patients without EVD-related infection (6 versus 7 days, P = 0.87), respectively. Interestingly no risk factor for EVD-related infection could be identified in our cohort of patients.

The evolution of neurocritical care

Although neurocritical care as a subspecialty is a relatively young field of medicine, its origins can be traced back to ancient times. This article focuses on the progression of neurocritical care from prehistoric trepanation procedures, through the development of mechanical ventilation, management of increased intracranial pressure, and traumatic brain injury, to the establishment of the first "real" intensive care units, and finally to modern monitoring in neurocritical care, management of post-cardiac arrest patients, and the diagnosis of brain death. This article also focuses on the future direction of neurocritical care.