Improving the role of intraventricular antimicrobial agents in the management of meningitis

Healthcare-Associated Ventriculitis in Children during COVID-19 Pandemic: Clinical Characteristics and Outcome of a First Infection

During the COVID-19 pandemic, patients in need of neurosurgical care suffered. Elective procedures were postponed, and emergency care visits decreased. Healthcare-associated ventriculitis (HAV) is a serious problem in children, with poor outcomes and frequent relapses. Our objective was to describe the clinical characteristics and the factors associated with a first HAV in children during two years of the pandemic. A retrospective cross-sectional study was performed from January 2021 to December 2022. The inclusion criteria were patients who developed a first HAV after a primary cerebrospinal fluid diversion procedure. The controls included patients without a first infection. Intraoperative and clinical data were extracted from medical records. A total of 199 CSF diversion surgeries were registered. A first infection occurred in 17 patients (8.5%), including 10 with external ventricular drain (EVD) and 6 with ventricular shunts. Gram-positive cocci were identified in 70.6%. Six patients recovered uneventfully, eight had relapse or superinfections, and three eventually died. Twenty patients were included as controls. Factors associated with a first infection were a younger age (median 9 vs. 102 months, p < 0.01), malnutrition (23.5% vs. 0%, p = 0.03), and an EVD placement (58.8% vs. 10%, p = 0.03). None of the intraoperative factors showed statistically significant differences. The rate of HAV was high. Most cases presented in children <1 year and with an EVD.

Prediction model of central nervous system infections in patients with severe traumatic brain injury after craniotomy

OBJECTIVE

The aim of this study was to develop and evaluate a nomogram to predict CNS infections in patients with severe traumatic brain injury (sTBI) after craniotomy.

METHODS

This retrospective study was conducted in consecutive adult patients with sTBI who were admitted to the neurointensive care unit (NCU) between January 2014 and September 2020. We applied the least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression analysis to construct the nomogram, and k-fold cross-validation (k=10) to validate it. The receiver operator characteristic area under the curve (AUC) and calibration curve were applied to evaluate the predictive effect of the nomogram. The clinical usefulness was investigated by decision curve analysis (DCA).

RESULTS

A total of 471 patients with sTBI who underwent surgical treatment were included, of whom 75 patients (15.7%) were diagnosed with CNS infections. The serum level of albumin, cerebrospinal fluid (CSF) otorrhoea at admission, CSF leakage, CSF sampling, and postoperative re-bleeding were associated with CNS infections and incorporated into the nomogram. The results showed that our model yielded satisfactory prediction performance with an AUC value of 0.962 in the training set and 0.942 in the internal validation. The calibration curve exhibited satisfactory concordance between the predicted and actual outcomes. The model had good clinical use since the DCA covered a large threshold probability.

CONCLUSION

We established a straightforward individualized nomogram for CNS infections in sTBI patients in the NCU, which could help physicians screen high-risk patients to perform early interventions to reduce the incidence of CNS infections in sTBI patients.

Systematic review of efficacy, safety and pharmacokinetics of intravenous and intraventricular vancomycin for central nervous system infections

Objective: The decision of vancomycin dosage for central nervous system (CNS) infections is still a challenge because its bactericidal nature in cerebrospinal fluid (CSF) has not been confirmed by human studies. This study systematically reviewed the literatures on vancomycin in patients with meningitis, ventriculitis, and CNS device-associated infections, to assess efficacy, safety, and pharmacokinetics to better serve as a practical reference.

Methods: Medline, Embase, and Cochrane Library were searched using terms vancomycin, Glycopeptides, meningitis, and central nervous system infections. Data were extracted including characteristics of participants, causative organism(s), administration, dosage, etc., The clinical response, microbiological response, adverse events and pharmacokinetic parameters were analyzed.

Results: Nineteen articles were included. Indications for vancomycin included meningitis, ventriculitis, and intracranial device infections. No serious adverse effects of intravenous (IV) and intraventricular (IVT) vancomycin have been reported. Dosages of IV and IVT vancomycin ranged from 1000–3000 mg/day and 2–20 mg/day. Duration of IV and IVT vancomycin therapy most commonly ranged from 3–27 days and 2–21 days. Therapeutic drug monitoring was conducted in 14 studies. Vancomycin levels in CSF in patients using IV and IVT vancomycin were varied widely from 0.06 to 22.3 mg/L and 2.5–292.9 mg/L. No clear relationships were found between vancomycin CSF levels and efficacy or toxicity.

Conclusion: Using vancomycin to treat CNS infections appears effective and safe based on current evidence. However, the optimal regimens are still unclear. Higher quality clinical trials are required to explore the vancomycin disposition within CNS.

Intrathecal therapy for tuberculous meningitis: propensity-matched cohort study

OBJECTIVE

The study aimed to determine the safety and efficacy of intrathecally administered isoniazid (INH) and prednisolone in addition to systemic anti-TB therapy and compare it with systemic anti-TB therapy alone in adult patients with tuberculous meningitis (TBM).

METHODS

In this retrospective study, patients were categorized into two groups: Group A patients received systematic anti-TB therapy alone, Group B patients received IT INH (50 mg) and prednisolone (25 mg) twice a week together with the same standard systemic anti-TB therapy as Group A, in addition to the standard systemic anti-TB therapy. Functional outcomes were compared between the two groups in a prosperity-matched cohort using propensity score matching (PSM) method.

RESULTS

A total of 198 patients with TBM were enrolled. After PSM, 30 patients from each group were analyzed, so that there was no significant difference in the characteristics of the two groups. Mortality at follow-up was significantly lower among patients receiving additional IT therapy (4/30, 13.3%) compared with matched patients receiving systemic anti-TB therapy alone (11/30, 36.7%, P value = 0.037).

CONCLUSIONS

In this propensity score-matched cohort, the addition of IT INH and prednisolone to systemic anti-TB therapy could be effective for the better outcome among adult TBM patients. Further large-scale, prospective, and randomized controlled trials are warranted to the best timing and indication of IT therapy.

Evaluation of Intraventricular/Intrathecal Antimicrobial Therapy in the Treatment of Nosocomial Meningitis Caused by Multidrug-Resistant Gram-Negative Bacteria after Central Nervous System Surgery

Introduction

Postoperative meningitis (POM) is an infection with high mortality and morbidity following central nervous system surgery due to trauma or tumor. Intrathecal/intraventricular (IT/IVT) antibiotic administrations have been considered as the last treatment options for multidrug-resistance (MDR) Gram-negative bacteria that do not respond to intravenous (IV) regimens. IT/IVT can bypass the blood-brain barrier, obtain a more effective antibiotic concentration in CSF, and reduce systemic side effects. We aimed to determine the characteristics of postoperative patients who were diagnosed with MDR POM during follow-up in our intensive care unit (ICU). Material and Methods. In this study, POM patients who were followed up in ICU after the central nervous system intervention between January 2016 and December 2019 and whose MDR Gram-negative bacteria were isolated from CSF were evaluated. As soon as the patients were diagnosed with POM, a catheter was inserted and treatment was started.

Results

Microbiological eradication was achieved in 3 ± 0.8 days with 30 mg/day amikacin treatment in POM due to K. pneumoniae and 3.7 ± 1.95 days with colistin sodium 10 mg/day treatment in POM due to A. baumannii via IT/IVT catheter. IT/IVT treatment was utilized for a median of 10 days and continued until the defined cure criteria were achieved. While cure was achieved in 6 of 14 POM cases, 8 of them were exitus. Discussion and Conclusion. To avoid the severe consequences of postoperative meningitis, acting fast and adding IT/IVT methods to parenteral administration routes by considering the distribution of MDR microorganisms within the hospital while planning effective treatment will increase the clinical success.

Antimicrobial use in central nervous system infections

PURPOSE OF REVIEW

Central nervous system (CNS) infections are associated with high rates of morbidity and mortality. The purpose of this review is to summarize current antimicrobial therapies, as well as, updates in the management of community-acquired meningitis and healthcare-associated meningitis and ventriculitis.

RECENT FINDINGS

Due to the increasing rates of multidrug resistant and extensively-drug resistant organisms, available antimicrobials are limited. Novel treatment options include newer systemic antimicrobials and antimicrobials that have previously limited data in the management of CNS infections. Although limited by retrospective data, intrathecal (IT) and intraventricular (IVT) routes of administration offer the opportunity for antimicrobials that conventionally have minimal cerebrospinal fluid (CSF) penetration to achieve high CSF concentrations while minimizing systemic exposure.

SUMMARY

Updates in the use of systemic, IT, and IVT antimicrobials offer promise as therapeutic options for CNS infections. Additional pharmacokinetic and prospective data are needed to confirm these findings.

Clinical Features of Post-Operative Nosocomial Meningitis in Adults and Evaluation of Efficiency of Intrathecal Treatment

Background: Post-operative nosocomial meningitis is a critical complication that develops in patients after neurosurgical interventions and operations. Patients and Methods: Data were collected for 65 patients who were diagnosed as having nosocomial meningitis after neurosurgery. The agent profile, clinical and biochemical differences in gram-negative and gram-positive meningitis, and the effectiveness of intrathecal antibiotic administration in cases with carbapenem-resistant gram-negative agents were evaluated. Results: Gram-negative bacteria were isolated in 52.3% of patients. In gram-negative cases of post-operative nosocomial meningitis, white blood cell count (p = 0.015), C-reactive protein (p = 0.001), cerebrospinal fluid leukocyte count (p = 0.0001), and protein (p = 0.0001) were higher, and glucose (p = 0.002) was lower. Concurrent bacteremia (p = 0.041), 14-day mortality (p = 0.022), and 30-day mortality (p = 0.023) were higher in gram-negative cases. Empirical treatment was appropriate in 78.5% of the patients. Seventeen patients (26.2%) received intrathecal antibiotic agents in addition to intravenous antibiotic treatment because of carbapenem-resistant gram-negative bacteria. Nine (53%) of the patients receiving intrathecal therapy had Acinetobacter baumannii as the agent, six had Klebsiella pneumoniae (35.4%), one had Pseudomonas aeruginosa (5.8%), and one had Providencia rettgeri (5.8%). The mean intravenous treatment duration was 21.4 ± 10.6 (4-60) days, and the mean intrathecal treatment duration was 17.6 ± 14.0 (1-51) days. Eleven patients received colistimethate sodium intrathecally (1 × 10 mg/d), three patients received amikacin intrathecally (1 × 10 mg/d), and three patients received gentamicin intrathecally (1 × 10 mg/d). Clinical and microbiologic treatment success was achieved in nine patients (53%). Conclusions: In cases of meningitis caused by carbapenem-resistant agents, intrathecal administration of antibiotic agents such as gentamicin, amikacin, and colistin with limited blood-brain barrier transition in intravenous administration will increase survival. Therefore, intrathecal antibiotic administration should be considered as a part of routine of nosocomial meningitis.

The Prospect of Nanoparticle Systems for Modulating Immune Cell Polarization During Central Nervous System Infection

The blood-brain barrier (BBB) selectively restricts the entry of molecules from peripheral circulation into the central nervous system (CNS) parenchyma. Despite this protective barrier, bacteria and other pathogens can still invade the CNS, often as a consequence of immune deficiencies or complications following neurosurgical procedures. These infections are difficult to treat since many bacteria, such as Staphylococcus aureus, encode a repertoire of virulence factors, can acquire antibiotic resistance, and form biofilm. Additionally, pathogens can leverage virulence factor production to polarize host immune cells towards an anti-inflammatory phenotype, leading to chronic infection. The difficulty of pathogen clearance is magnified by the fact that antibiotics and other treatments cannot easily penetrate the BBB, which requires extended regimens to achieve therapeutic concentrations. Nanoparticle systems are rapidly emerging as a promising platform to treat a range of CNS disorders. Nanoparticles have several advantages, as they can be engineered to cross the BBB with specific functionality to increase cellular and molecular targeting, have controlled release of therapeutic agents, and superior bioavailability and circulation compared to traditional therapies. Within the CNS environment, therapeutic actions are not limited to directly targeting the pathogen, but can also be tailored to modulate immune cell activation to promote infection resolution. This perspective highlights the factors leading to infection persistence in the CNS and discusses how novel nanoparticle therapies can be engineered to provide enhanced treatment, specifically through modulation of immune cell polarization.

A Clinical Study on the Use of Intraventricular Polymyxin B Supplemented by Continuous External Ventricular Drainage in the Treatment of Drug-Resistant Gram-Negative Bacilli Intracranial Infection

Purpose

To investigate the clinical effect of ventricular polymyxin B supplemented by continuous external ventricular drainage in the treatment of intracranial infection with multidrug-resistant (MDR) or extensively drug-resistant (XDR) Gram-negative (G-) bacilli following neurosurgery.

Patients and Methods

A retrospective analysis was performed on 28 patients who had G-bacilli intracranial infection following neurosurgery in our department between January 2017 and December 2019. The patients were treated with intraventricular polymyxin B supplemented by continuous external ventricular drainage. The clinical characteristics, treatment process, cerebrospinal-fluid-related indicators, results and prognosis were analysed.

Results

All of 28 patients developed an infection subsequent to neurosurgery, and cerebrospinal fluid (CSF) cultures demonstrated MDR/XDR G- bacilli, including Acinetobacter baumannii in 14 cases, Klebsiella pneumoniae in 9 cases, Pseudomonas aeruginosa in 3 cases, and Enterobacter cloacae in 2 cases. The ventricular drainage tube remained unobstructed in all patients during treatment, and intraventricular polymyxin B combined with intravenous antibiotics were administered each day. The duration of treatment with intraventricular polymyxin B was 14.96±4.28 days, and the time required to obtain a negative CSF culture was 8.23±4.02 days. The bacterial clearance rate from cerebrospinal fluid was 92.9% (26/28), and the clinical cure rate was 82.1% (23/28). Among them, 18 patients underwent ventriculoperitoneal shunt insertion for hydrocephalus 82.5 (59.5,114.75) days after the infection was cured, and the mortality rate was 17.6% (5/28). There was no significant change in patient blood creatinine levels before and after treatment. Cured patients were followed up for 4 months to 3 years, and no recurrences were observed.

Conclusion

Treatment of intracranial infection with MDR/XDR G- bacilli using early intraventricular polymyxin B supplemented by continuous external ventricular drainage treatment may be a safe and effective treatment strategy.

Polymyxin B combinations with FDA-approved non-antibiotic phenothiazine drugs targeting multi-drug resistance of Gram-negative pathogens

The status quo for combating uprising antibacterial resistance is to employ synergistic combinations of antibiotics. Nevertheless, the currently available combination therapies are fast becoming untenable. Combining antibiotics with various FDA-approved non-antibiotic drugs has emerged as a novel strategy against otherwise untreatable multi-drug resistant (MDR) pathogens. The apex of this study was to investigate the mechanisms of antibacterial synergy of the combination of polymyxin B with the phenothiazines against the MDR Gram-negative pathogens Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa. The synergistic antibacterial effects were tested using checkerboard and static time-kill assays. Electron microscopy (EM) and untargeted metabolomics were used to ascertain the mechanism(s) of the antibacterial synergy. The combination of polymyxin B and the phenothiazines showed synergistic antibacterial activity in checkerboard and static time-kill assays at clinically relevant concentrations against both polymyxin-susceptible and polymyxin-resistant isolates. EM revealed that the polymyxin B-prochlorperazine combination resulted in greater damage to the bacterial cell compared to each drug monotherapy. In metabolomics, at 0.5 h, polymyxin B monotherapy and the combination (to a greatest extent) disorganised the bacterial cell envelope as manifested by a major perturbation in bacterial membrane lipids (glycerophospholipids and fatty acids), peptidoglycan and lipopolysaccharide (LPS) biosynthesis. At the late time exposure (4 h), the aforementioned effects (except LPS biosynthesis) perpetuated mainly with the combination therapy, indicating the disorganising bacterial membrane biogenesis is potentially behind the mechanisms of antibacterial synergy. In conclusion, the study highlights the potential usefulness of the combination of polymyxin B with phenothiazines for the treatment of polymyxin-resistant Gram-negative infections (e.g. CNS infections).

Intrathecal Antibacterial and Antifungal Therapies

Intrathecal administration of anti-infectives is indicated in central nervous system infections by multiresistant pathogens when drugs that can reach adequate cerebrospinal fluid (CSF) concentrations by systemic therapy are not available. Antibiotics that readily pass the blood-brain and blood-CSF barriers and/or that have low toxicity allowing an increase in the daily dosage should not be used for intrathecal therapy. Intrathecal therapy is accompanied by systemic treatment. Antibacterials indispensable for intrathecal therapy include aminoglycosides, colistin, daptomycin, tigecycline, and vancomycin. Limited experience suggests the utility of the antifungals amphotericin B and caspofungin. Intraventricular administration ensures distribution throughout the CSF compartment, whereas intralumbar dosing often fails to attain adequate antibiotic concentrations in the ventricles. The individual dose is determined by the estimated size of the CSF space and by the estimated clearance from CSF. For moderately lipophilic anti-infectives with a molecular weight above approximately 1,000 g/mol, as well as for hydrophilic drugs with a molecular weight above approximately 400 g/mol, one daily dose is normally adequate. The ventricular drain should be clamped for 15 to 120 min to facilitate the distribution of the anti-infective in the CSF space. Therapeutic drug monitoring of the trough levels is necessary only in cases of therapeutic failure.

Calculated parenteral initial therapy of bacterial infections: Bacterial meningitis

This is the thirteenth chapter of the guideline "Calculated initial parenteral treatment of bacterial infections in adults - update 2018" in the 2^nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience. Bacterial meningitis is a life-threatening infectious disease with high mortality and disability rates requiring prompt initiation of antimicrobial treatment to lower these rates.

Prevención y tratamiento de las infecciones del sitio operatorio en neurocirugía. Estado del arte

El manejo adecuado de las infecciones del sitio operatorio (ISO) en neurocirugía es fundamental para la disminución de la carga de morbilidad y mortalidad en estos pacientes. La sospecha y confirmación diagnóstica asociadas al aislamiento microbiológico son esenciales para asegurar el tratamiento oportuno y el adecuado gerenciamiento de antibióticos. En esta revisión se presenta de forma resumida los puntos fundamentales para la prevención y el tratamiento de infecciones del sitio operatorio en neurocirugía y se incluye un apartado sobre el uso de antibióticos intratecales/intraventriculares.

Antibiotic Distribution into Cerebrospinal Fluid: Can Dosing Safely Account for Drug and Disease Factors in the Treatment of Ventriculostomy-Associated Infections?

Ventriculostomy-associated infections, or ventriculitis, in critically ill patients are associated with considerable morbidity. Efficacious antibiotic dosing for the treatment of these infections may be complicated by altered antibiotic concentrations in the cerebrospinal fluid due to variable meningeal inflammation and antibiotic properties. Therefore, doses used to treat infections with a higher degree of meningeal inflammation (such as meningitis) may often fail to achieve equivalent exposures in patients with ventriculostomy-associated infections such as ventriculitis. This paper aims to review the disease burden, infection rates, and common pathogens associated with ventriculostomy-associated infections. This review also seeks to describe the disease- and drug-related factors that influence antibiotic distribution into cerebrospinal fluid and provide a critical appraisal of current dosing of antibiotics commonly used to treat these types of infections. A Medline search of relevant articles was conducted and used to support a review of cerebrospinal fluid penetration of vancomycin, including critical appraisal of the recent paper by Beach et al. recently published in this journal. We found that in the intensive care unit, ventriculostomy-associated infections are the most common and serious complication of external ventricular drain insertion and often result in prolonged patient stay and increased healthcare costs. Reported infection rates are extremely variable (between 0 and 45%), hindered by the inherent diagnostic difficulty. Both Gram-positive and Gram-negative organisms are associated with such infections and the rise of multi-drug-resistant pathogens means that effective treatment is an ongoing challenge. Disease factors that may need to be considered are reduced meningeal inflammation and the presence of critical illness; drug factors include physiochemical properties, degree of plasma-protein binding, and affinity to active transporter proteins present in the blood-cerebrospinal fluid barrier. The relationship between cerebrospinal fluid antibiotic exposures in the setting of ventriculostomy-associated infection and clinical response has not been fully elucidated for many of the antibiotics commonly used in its treatment. More thorough and clinically relevant investigations are needed to better define blood pharmacokinetic/pharmacodynamics targets and optimal therapeutic exposures for treatment of ventriculostomy-associated infections. It is hoped that this future research will be able to provide clearer recommendations for clinicians frequently faced with dosing-related dilemmas when treating patients with these challenging infections.

Intrathecal and intraventricular antibiotics for postoperative Gram-negative meningitis and ventriculitis

Background:

Postoperative meningitis is a growing cause of concern, especially with the evolution of multidrug-resistant organism. The authors evaluate the use of intraventricular/intrathecal (IVT/IT) antibiotics for postoperative gram-negative meningitis in patients whom intravenous antibiotics were ineffective.

Methods:

Medical records were retrospectively reviewed and neurosurgery patients with gram-negative postoperative infection meningitis/ventriculitis were enrolled in the study. Their demographics, hospital course, and outcomes were recorded in a pro forma and analyzed using Statistical Package for the Social Sciences, version 19.

Results:

The review identified 21 patients with postneurosurgical gram-negative meningitis/ventriculitis who were treated with IVT or IT antibiotics. The most common organism was Acinetobacter species (n = 14; 66%). Amikacin was used in 7 patients, polymyxin B in 9 patients, and colistin in 5 patients. A combination of antibiotics was used in one patient. Cerebrospinal fluid sterility was achieved in all patients with no incidence of relapse. There was a single death, though that was not related to the infectious process as the patient had a massive pulmonary embolism.

Conclusion:

The findings of this study suggest that IVT and IT antibiotic therapy is a useful option in patients who are nonresponsive to standard intravenous therapy with little or no side effects.

Intracerebroventricular drug administration

Among the various routes of drug administration, perhaps the least studied is intracerebroventricular (ICV) administration. This route has been shown to be particularly useful in administering to the central nervous system (CNS) drugs that do not cross the blood-brain barrier readily. As such, the ICV route is a valuable option for providing therapeutic CNS drug concentrations to treat patients with CNS infectious and neoplastic diseases. This route of drug administration also has the advantage of minimizing systemic toxicity.

2017 Infectious Diseases Society of America's Clinical Practice Guidelines for Healthcare-Associated Ventriculitis and Meningitis

The Infectious Diseases Society of America (IDSA) Standards and Practice Guidelines Committee collaborated with partner organizations to convene a panel of 10 experts on healthcare-associated ventriculitis and meningitis. The panel represented pediatric and adult specialists in the field of infectious diseases and represented other organizations whose members care for patients with healthcare-associated ventriculitis and meningitis (American Academy of Neurology, American Association of Neurological Surgeons, and Neurocritical Care Society). The panel reviewed articles based on literature reviews, review articles and book chapters, evaluated the evidence and drafted recommendations. Questions were reviewed and approved by panel members. Subcategories were included for some questions based on specific populations of patients who may develop healthcare-associated ventriculitis and meningitis after the following procedures or situations: cerebrospinal fluid shunts, cerebrospinal fluid drains, implantation of intrathecal infusion pumps, implantation of deep brain stimulation hardware, and general neurosurgery and head trauma. Recommendations were followed by the strength of the recommendation and the quality of the evidence supporting the recommendation. Many recommendations, however, were based on expert opinion because rigorous clinical data are not available. These guidelines represent a practical and useful approach to assist practicing clinicians in the management of these challenging infections.

Management of infections associated with neurocritical care

The reported incidence of hospital-acquired infections (HAIs) in the neurointensive care unit (NICU) ranges from 20% to 30%. HAIs in US hospitals cost between $28 and $45 billion per year in direct medical costs. These infections are associated with increased length of hospital stay and increased morbidity and mortality. Infection risk is increased in NICU patients due to medication side-effects, catheter and line placement, neurosurgical procedures, and acquired immune suppression secondary to steroid/barbiturate use and brain injury itself. Some of these infections may be preventable but many are not. Their appearance do not always constitute a failure of prevention or physician error. Neurointensivists require indepth knowledge of common nosocomial infections, their diagnosis and treatment, and an approach to evidence-based practices that improve processes of care and reduce HAIs.

An international based survey about preferences in neurosurgical irrigation fluids in neurotrauma procedures

Background: Traumatic brain injury surgery is the most frequently performed by neurosurgeons. The use of 0.9% saline solution (normal saline) irrigation and other solutions during neurosurgical procedures has been considered a cause of neural tissue injury. The normal saline has been used for many years, but at cellular level it may cause harmful changes. The emergence of new solutions, such as artificial cerebrospinal fluid and Ringer's lactate, seem to produce less damage effects on brain tissue. The aim of this study is to evaluate the trends in use of irrigation solutions in traumatic brain injury surgeries.

Materials and Methods: This study was conducted through a web-based survey sent to 40 neurosurgeons worldwide.

Results: Over the period of the study data was collected from the 40 physicians and the 100% of the respondents used any type of irrigation solution during neurosurgery. Conclusion: The use of normal saline in brain surgery is a widespread practice worldwide, despite the negative effects on neural tissue as it may contribute to further damage. The conception of new irrigation solutions for neurosurgery, especially in traumatic brain injury, may be a useful alternative for future studies and to expand our knowledge on this topic.

Adjunctive intraventricular antibiotic therapy for bacterial central nervous system infections in critically ill patients with traumatic brain injury

BACKGROUND

Limited data exist on the role of adjunctive intraventricular (IVT) antibiotics for the treatment of central nervous system (CNS) infections in traumatic brain injury (TBI) patients.

OBJECTIVE

To evaluate differences in CNS infection cure rates for TBI patients who received adjunctive IVT antibiotics compared with intravenous (IV) antibiotics alone.

METHODS

We retrospectively identified patients with TBI and bacterial CNS infections admitted to the trauma intensive care unit (ICU) from 1997 to 2013. Study patients received IV and IVT antibiotics, and control patients received IV antibiotics alone. Clinical and microbiological cure rates were determined from patient records, in addition to ICU and hospital lengths of stay (LOSs), ventilator days, and hospital mortality.

RESULTS

A total of 83 patients were enrolled (32 study and 51 control). The duration of IV antibiotics was similar in both groups (10 vs 12 days, P = 0.14), and the study group received IVT antibiotics for a median of 9 days. Microbiological cure rates were 84% and 82% in study and control groups, respectively (P = 0.95). Clinical cure rates were similar at all time points. No significant differences were seen in days of mechanical ventilation, ICU or hospital LOS, or hospital mortality. When only patients with external ventricular drains were compared, cure rates remained similar between groups.

CONCLUSIONS

TBI patients with CNS infections had similar microbiological and clinical cure rates whether they were treated with adjunctive IVT antibiotics or IV antibiotics alone. Shorter than recommended durations of antibiotic therapy still resulted in acceptable cure rates and similar clinically relevant outcomes.

Systematic review of efficacy, pharmacokinetics, and administration of intraventricular vancomycin in adults

Central nervous system infections requiring treatment with intraventricular (IVT) vancomycin are becoming increasingly common with advent of intracranial devices and increasing prevalence of multi-drug resistant and nosocomial organisms. Administering vancomycin via IVT route bypasses the blood-brain barrier to allow localized and controlled delivery directly to the desired site of action, achieving high concentrations for more reliable bactericidal action. This article systematically reviews current literature on IVT vancomycin in adults, compiles current knowledge, and integrates available evidence to serve as a practical reference.Medline (1946-July 2012), Embase (1974-July 2012), and International Pharmaceutical Abstracts (1970-July 2012) were searched using terms vancomycin, intraventricular, shunt infection, cerebrospinal fluid, and intraventriculitis. Seventeen articles were included in this review. Indications for IVT vancomycin included meningitis unresponsive to intravenous antibiotics, ventriculitis, and intracranial device infections. No serious adverse effects following IVT vancomycin have been reported. Dosages reported in literature ranged from 0.075-50 mg/day, with the most evidence for dosages of 5 to 20 mg/day. Duration of therapy most commonly ranged from 7 to 21 days. Therapeutic drug monitoring was reported in 11 studies, with CSF vancomycin levels varying widely from 1.1 to 812.6 mg/L, without clear relationships between CSF levels and efficacy or toxicity. Using IVT vancomycin to treat meningitis, ventriculitis, and CNS device-associated infections appears safe and effective based on current evidence. Optimal regimens are still unclear, and dosing of IVT vancomycin requires intricate consideration of patient specific factors and their impact on CNS pathophysiology. Higher-quality clinical trials are necessary to characterize the disposition of vancomycin within CNS, and to determine models for various pathophysiological conditions to facilitate better understanding of effects on pharmacokinetic and pharmacodynamic parameters.

Intraventricular and lumbar intrathecal administration of antibiotics in postneurosurgical patients with meningitis and/or ventriculitis in a serious clinical state

Object

To date, reports on the clinical efficacy of intraventricularly and intrathecally administered antibiotics for the treatment of neurosurgical ventriculitis and meningitis in adults are limited. The authors aimed to evaluate the efficacy and safety of the intraventricular (IVT) and lumbar intrathecal (IT) administration of antibiotics in critically ill neurosurgical patients.

Methods

Thirty-four postneurosurgical patients with meningitis and ventriculitis were studied. Intraventricular/lumbar intrathecal antibiotics were administered due to positive CSF cultures persisting despite the use of intravenous antibiotics. The time period until CSF sterilization, changes in clinical state, and efficacy of different routes of antibiotic administration were evaluated.

Results

The mean time necessary to obtain CSF sterilization was 2.9 ± 2.7 days (range 1–12 days). The CSF cultures became negative within 24 hours after the administration of IVT/IT antibiotics in 17 patients (50%) and up to 48 hours in a further 6 patients (18%). The clinical outcome of patients assessed by the modified Rankin Scale improved in 17 patients (50%), stayed unchanged in 10 patients (29%), and was impaired in 1 patient (3%). Six patients (18%) died; however, 2 of them died due to reasons not directly related to meningitis or ventriculitis, so the overall mortality rate for meningitis and/or ventriculitis was 11.8% in this group of patients. All patients with ventriculitis (n = 4) were treated by antibiotics administered via the IVT route. The average time to CSF sterilization was 6.5 days in the patients with ventriculitis. Thirty patients had clinical signs of meningitis without ventriculitis. Despite the higher ratio of unfavorable Gram-negative meningitis in the subgroup of patients treated via lumbar drainage, the mean duration of CSF sterilization was 2.2 days compared with 2.6 days in the subgroup treated via external ventricular drainage, a difference that was not statistically significant (p = 0.3). Adverse effects of IVT/IT antibiotics appeared in 3 of 34 patients and were of low clinical significance.

Conclusions

Intraventricular/lumbar intrathecal antibiotics can lead to very quick CSF sterilization in postneurosurgical patients with meningitis and ventriculitis. The relapse rate of meningitis and/or ventriculitis is also very low among patients treated by IVT/IT antibiotics. Intraventricular/lumbar intrathecal administration of antibiotics appears to be an effective and safe treatment for infections of the CNS caused by multidrug-resistant organisms. In patients with signs of ventriculitis, the authors prefer the IVT route of antibiotics. This study did not prove a lower efficacy of administration of antibiotics via lumbar drainage compared with the ventricular route in patients with meningitis.

Infectious intracranial complications in the neuro-ICU patient population

PURPOSE OF REVIEW

To provide an overview of infectious intracranial complications secondary to invasive procedures or trauma in the neuro-ICU patient population. Nosocomial infections of the central nervous system are a serious complication contributing to morbidity, prolonged length of stay in the ICU and/or hospital, and mortality of neurocritical care patients.

RECENT FINDINGS

Any type of neurosurgical interventions, specifically ventriculostomy/external ventricular drainage, constitutes a major risk factor for infectious intracranial complications. Other predisposing factors are comorbidities with immunocompromised state and the presence of a distant focus of infection. The emergence of multiresistant pathogens adds to the complexity of the management of infectious intracranial complications. In recent years, several antimicrobial agents suitable for the treatment of nosocomial central nervous system infections have been extensively studied with respect to pharmacodynamics and pharmacokinetics in serum and - of special importance in the neurocritical care setting - cerebrospinal fluid.

SUMMARY

Despite recent advances in prevention and treatment, the management of nosocomial intracranial infections still poses a challenge to the neuro-ICU specialist and must consider timely diagnosis and prompt initiation of appropriate antibiotic therapy. This review focuses on the definition, epidemiology, clinical features, and therapeutical approach to this distinct complication of neurocritical care.

[Case of an elderly patient with community acquired bacterial meningitis due to extended spectrum β lactamase producing Escherichia coli]

Community acquired bacterial meningitis due to extended spectrum β lactamase-producing Escherichia coli is very rare. We report the case of a 72-year-old woman being treated for longstanding diabetes mellitus. She developed lower back pain accompanied by elevated body temperature, and was transported to the emergency unit in our hospital five days later because of impaired consciousness. An abdominal plane CT showed acute pyelonephritis and a brain MRI showed inflammatory exudate in the posterior horn of her bilateral ventricles. A lumbar puncture was performed, and examination of the cerebrospinal fluid revealed a marked elevation in her cell count (polymorphonuclear leukocytes dominant) that we diagnosed as bacterial meningitis. Initially, she was treated with intravenous meropenem, ceftriaxon, and vancomycin. Extended spectrum β lactamase-producing Escherichia coli were then detected in her urinary and blood cultures, and the antibiotics were changed to intravenous meropenem, gentamicin, and intrathecal gentamicin. Her clinical symptoms improved, but her inflammatory reaction was prolonged and we detected spondylitis. She was then treated with levofloxacin, and the inflammatory reaction improved. Extended spectrum β lactamase-producing Escherichia coli should be taken into consideration as a cause of community acquired bacterial meningitis.

Prolonged triple therapy for persistent multidrug-resistant Acinetobacter baumannii ventriculitis

PURPOSE

A case of persistent multidrug-resistant (MDR) Acinetobacter baumannii ventriculitis successfully treated with a prolonged and novel combination of antimicrobials is reported.

SUMMARY

A 38-year-old, 84-kg Caucasian woman with a recent history of craniotomy was admitted with nausea, fever, headache, photophobia, and drainage from her craniotomy incision. She underwent a repeat craniotomy on hospital day 4 with abscess debridement and repair of a cerebrospinal fluid leak. Cultures grew MDR A. baumannii, coagulase-negative Staphylococcus species, and methicillin-resistant Staphylococcus aureus. Based on the limited published pharmacokinetic and pharmacodynamic data for colistin, we determined a favorable outcome with i.v. colistin monotherapy was unlikely and decided to treat the patient with simultaneous i.v. and intraventricular colistin, as well as intraventricular tobramycin and i.v. rifampin. She was treated with a total of 36 days of intraventricular colistin, 40 days of intraventricular tobramycin, 51 days of i.v. colistin and rifampin, and 56 days i.v. vancomycin for infection that persisted despite multiple debridements. The patient had subsequent improvement in clinical manifestations and eradication of infection. She was subsequently discharged to an acute rehabilitation facility on hospital day 77 with posttreatment sequelae including mental impairment and renal failure requiring hemodialysis. Follow-up visits revealed significant improvement in her mental status, speech, and strength on the side not affected by the stroke.

CONCLUSION

Prolonged combination therapy with intraventricular colistin and tobramycin plus i.v. colistin, rifampin, and vancomycin led to the resolution of a persistent central nervous system infection caused by MDR A. baumannii.

Fulminant ependymitis following intraventricular rupture of brain abscess

A 48-year-old man with a history of a penetrating brain injury was referred with a presumptive diagnosis of bacterial meningitis. Examination revealed a brain abscess in addition to meningitis. Blood and cerebrospinal fluid (CSF) cultures were negative for bacteria, and empirical IV antibiotic therapy with vancomycin (VCM) and meropenem was initiated. Despite initial improvement, however, his condition rapidly deteriorated into coma following intraventricular rupture of the abscess and hydrocephalus. Thereafter, an emergency ventriculostomy was performed and the abscess was evacuated. Bacterial cultures of the pus were negative. To manage the hydrocephalus, 150-200 ml of CSF were drained daily. Intraventricular administration of VCM (20 mg q.d.) was added to the IV antibiotic therapeutic regimen after surgery. Although the primary abscess rapidly decreased in size, ependymitis developed in the fourth ventricle. This new lesion, which resulted from CSF dissemination from the primary abscess, was refractory to treatment, and eventually disappeared after the intraventricular VCM dosage was increased from 20 to 30 mg and continued for 30 days. A possible reason for the development of fulminant ependymitis and why it was refractory to treatment despite the shrinkage of the primary lesion may be that physiological CSF flow from the lateral to the fourth ventricle was lost due to CSF drainage, and the stagnant CSF flow coupled with an insufficient VCM level in the fourth ventricle facilitated the rapid growth of pathogens. Although intraventricular antibiotic administration is efficacious for treating ruptured brain abscesses, it may be associated with the unexpected development of secondary lesions.

Penetration of drugs through the blood-cerebrospinal fluid/blood-brain barrier for treatment of central nervous system infections

The entry of anti-infectives into the central nervous system (CNS) depends on the compartment studied, molecular size, electric charge, lipophilicity, plasma protein binding, affinity to active transport systems at the blood-brain/blood-cerebrospinal fluid (CSF) barrier, and host factors such as meningeal inflammation and CSF flow. Since concentrations in microdialysates and abscesses are not frequently available for humans, this review focuses on drug CSF concentrations. The ideal compound to treat CNS infections is of small molecular size, is moderately lipophilic, has a low level of plasma protein binding, has a volume of distribution of around 1 liter/kg, and is not a strong ligand of an efflux pump at the blood-brain or blood-CSF barrier. When several equally active compounds are available, a drug which comes close to these physicochemical and pharmacokinetic properties should be preferred. Several anti-infectives (e.g., isoniazid, pyrazinamide, linezolid, metronidazole, fluconazole, and some fluoroquinolones) reach a CSF-to-serum ratio of the areas under the curves close to 1.0 and, therefore, are extremely valuable for the treatment of CNS infections. In many cases, however, pharmacokinetics have to be balanced against in vitro activity. Direct injection of drugs, which do not readily penetrate into the CNS, into the ventricular or lumbar CSF is indicated when other effective therapeutic options are unavailable.

Possible detrimental effects of neurosurgical irrigation fluids on neural tissue: an evidence based analysis of various irrigants used in contemporary neurosurgical practice

Physiological saline and other solutions used as irrigation fluids during neurosurgical procedures have long been debated to cause adverse effects on neural tissue. Laboratory based research over the past fifty years has described the possible harm caused to central nervous system cells by normal saline, and has advocated the use of safer alternatives such as lactated Ringer's solution and artificial cerebrospinal fluid. However, there is a dearth of corresponding clinical studies to support this standpoint. Worldwide, normal saline remains the most widely used neurosurgical irrigation fluid. We have attempted to document the preference of practicing neurosurgeons worldwide regarding the irrigation fluids via an electronic mail survey, and have analyzed the available evidence on the relative safety of various irrigation fluids. We recommend the use of lactated Ringer's solution and artificial cerebrospinal fluid as neurosurgical irrigants, especially during neuroendoscopy and longer procedures requiring application of copious amount of irrigation fluid.