Current Practices of Intraventricular Antibiotic Therapy in the Treatment of Meningitis and Ventriculitis: Results from a Multicenter Retrospective Cohort Study

Intraventricular or intrathecal polymyxin B for treatment of post-neurosurgical intracranial infection caused by carbapenem-resistant gram-negative bacteria: a 8-year retrospective study

PURPOSE

Post-neurosurgical intracranial infection caused by carbapenem-resistant gram-negative bacteria (CRGNB) is a life-threatening complication. This study aimed to assess the current practices and clinical outcomes of intravenous (IV) combined with intraventricular (IVT)/intrathecal (ITH) polymyxin B in treating CRGNB intracranial infection.

METHODS

A retrospective study was conducted on patients with post-neurosurgical intracranial infection due to CRGNB from January 2013 to December 2020. Clinical characteristics and treatment outcomes were collected and described. Kaplan-Meier survival and multivariate logistic regression analyses were performed.

RESULTS

The study included 114 patients, of which 72 received systemic antimicrobial therapy combined with IVT/ITH polymyxin B, and 42 received IV administration alone. Most infections were caused by carbapenem-resistant Acinetobacter baumannii (CRAB, 63.2%), followed by carbapenem-resistant Klebsiella pneumoniae (CRKP, 31.6%). Compared with the IV group, the IVT/ITH group had a higher cerebrospinal fluid (CSF) sterilization rate in 7 days (p < 0.001) and lower 30-day mortality (p = 0.032). In the IVT/ITH group, patients with CRKP infection had a higher initial fever (p = 0.014), higher incidence of bloodstream infection (p = 0.040), lower CSF sterilization in 7 days (p < 0.001), and higher 30-day mortality (p = 0.005) than those with CRAB infection. Multivariate logistic regression analysis revealed that the duration of IVT/ITH polymyxin B (p = 0.021) was independently associated with 30-day mortality.

CONCLUSIONS

Intravenous combined with IVT/ITH polymyxin B increased CSF microbiological eradication and improved clinical outcomes. CRKP intracranial infections may lead to more difficult treatment and thus warrant attention and further optimized treatment.

Comprehensive Therapeutic Approaches to Tuberculous Meningitis: Pharmacokinetics, Combined Dosing, and Advanced Intrathecal Therapies

Tuberculous meningitis (TBM) presents a critical neurologic emergency characterized by high mortality and morbidity rates, necessitating immediate therapeutic intervention, often ahead of definitive microbiological and molecular diagnoses. The primary hurdle in effective TBM treatment is the blood-brain barrier (BBB), which significantly restricts the delivery of anti-tuberculous medications to the central nervous system (CNS), leading to subtherapeutic drug levels and poor treatment outcomes. The standard regimen for initial TBM treatment frequently falls short, followed by adverse side effects, vasculitis, and hydrocephalus, driving the condition toward a refractory state. To overcome this obstacle, intrathecal (IT) sustained release of anti-TB medication emerges as a promising approach. This method enables a steady, uninterrupted, and prolonged release of medication directly into the cerebrospinal fluid (CSF), thus preventing systemic side effects by limiting drug exposure to the rest of the body. Our review diligently investigates the existing literature and treatment methodologies, aiming to highlight their shortcomings. As part of our enhanced strategy for sustained IT anti-TB delivery, we particularly seek to explore the utilization of nanoparticle-infused hydrogels containing isoniazid (INH) and rifampicin (RIF), alongside osmotic pump usage, as innovative treatments for TBM. This comprehensive review delineates an optimized framework for the management of TBM, including an integrated approach that combines pharmacokinetic insights, concomitant drug administration strategies, and the latest advancements in IT and intraventricular (IVT) therapy for CNS infections. By proposing a multifaceted treatment strategy, this analysis aims to enhance the clinical outcomes for TBM patients, highlighting the critical role of targeted drug delivery in overcoming the formidable challenges presented by the blood-brain barrier and the complex pathophysiology of TBM.

Early Intraventricular Antibiotic Therapy Improved In-Hospital-Mortality in Neurocritical Patients with Multidrug-Resistant Bacterial Nosocomial Meningitis and Ventriculitis

BACKGROUND

Hospital-acquired multidrug-resistant (MDR) bacterial meningitis and/or ventriculitis (MEN) is a severe condition associated with high mortality. The risk factors related to in-hospital mortality of patients with MDR bacterial MEN are unknown. We aimed to examine factors related to in-hospital mortality and evaluate their prognostic value in patients with MDR bacterial MEN treated in the neurointensive care unit.

METHODS

This was a single-center retrospective cohort study of critically ill neurosurgical patients with MDR bacterial MEN admitted to our hospital between January 2003 and March 2021. Data on demographics, admission variables, treatment, time to start of intraventricular (IVT) therapy, and in-hospital mortality were analyzed. Both univariate and multivariable analyses were performed to identify determinants of in-hospital mortality.

RESULTS

All 142 included patients received systemic antibiotic therapy, and 102 of them received concomitant IVT treatment. The median time to start of IVT treatment was 2 days (interquartile range 1-5 days). The time to start of IVT treatment had an effect on in-hospital mortality (hazard ratio 1.17; 95% confidence interval 1.02-1.34; adjusted p = 0.030). The cutoff time to initiate IVT treatment was identified at 3 days: patients treated within 3 days had a higher cerebrospinal fluid (CSF) sterilization rate (81.5%) and a shorter median time to CSF sterilization (7 days) compared with patients who received delayed IVT treatment (> 3 days) (48.6% and 11.5 days, respectively) and those who received intravenous antibiotics alone (42.5% and 10 days, respectively).

CONCLUSIONS

Early IVT antibiotics were associated with superior outcomes in terms of the in-hospital mortality rate, time to CSF sterilization, and CSF sterilization rate compared with delayed IVT antibiotics and intravenous antibiotics alone.

Stereotactic placement of dual lumen catheter system for continuous drainage, irrigation, and intraventricular antibiotic therapy for treatment of brain abscess with ventriculitis - A case report and literature review

Background

Cerebral abscesses complicated by ventriculitis present significant treatment challenges, often associated with high morbidity and mortality. Traditional management approaches, including systemic antibiotic therapy and external ventricular drainage (EVD), face limitations due to the blood-brain barrier and risks of catheter-related complications. This report discusses a case where the dual-lumen catheter system, an innovative neurosurgical tool integrating continuous irrigation with drainage, was employed.

Case Description

A patient presented with a cerebral abscess ruptured into the ventricle, leading to ventriculitis. Conventional treatment options were limited due to the abscess's deep and eloquent location and the associated risk of complications from standard EVD. The dual lumen system was chosen for its ability to provide continuous irrigation and drainage, effectively addressing issues of catheter blockage and enhancing localized antibiotic delivery. The system was used to create a single stereotactic tract for simultaneous treatment of the abscess and ventriculitis. This approach allowed for a more controlled and effective treatment process, resulting in rapid resolution of the conditions without chronic hydrocephalus development or further complications.

Conclusion

The use of the dual lumen system represented a significant advancement in this case, addressing the limitations of conventional treatments. Its ability to maintain intracranial pressure within optimal limits while providing localized, continuous treatment was pivotal. This case highlights the potential of the dual lumen catheter in managing complex neurosurgical infections and underscores the need for further research to establish its efficacy in broader clinical applications.

NEAT1 in inflammatory infectious diseases: An integrated perspective on molecular modulation

The long non-coding RNA (lncRNA), NEAT1, has emerged as a central figure in the intricate network of molecular regulators in inflammatory infectious diseases (IIDs). The review initiates a comprehensive exploration of NEAT1's multifaceted roles and molecular interactions in the context of these complex diseases. The study begins by acknowledging the global health burden of IIDs, underscoring the urgency for innovative insights into their pathogenesis and therapeutic avenues. NEAT1 is introduced as a pivotal lncRNA with growing relevance in immune responses and inflammatory processes. The core of this review unravels the NEAT1 landscape, elucidating its involvement in the modulation of immune signalling pathways, regulation of inflammatory cytokines, and interactions with various immune cells during infection. It explores NEAT1's role in orchestrating immune responses and balancing host defence mechanisms with the risk of immunopathology. Furthermore, the review underscores the clinical significance of NEAT1 in infectious diseases, discussing its associations with disease severity, prognosis, and potential as a diagnostic and therapeutic target. It provides insights into ongoing research endeavours aimed at harnessing NEAT1 for innovative disease management strategies, including developing RNA-based therapeutics. Concluding on a forward-looking note, the review highlights the broader implications of NEAT1 in the context of emerging infectious diseases and the possibility for precision medicine approaches that leverage NEAT1's regulatory capacities. In summary, this review illuminates the pivotal role of NEAT1 in IIDs by navigating its complex landscape, offering profound insights into its implications for disease pathogenesis and the development of targeted therapies.

Treatment of cerebral ventriculitis with a new self-irrigating catheter system: narrative review and case series

Cerebral ventriculitis is a life-threatening condition that requires prompt and effective pharmacological intervention. The continuous irrigation of the cerebral ventricles with fluid and its drainage is a system to remove toxic substances and infectious residues in the ventricles; this system is called IRRAflow®. We used this kind of ventricular irrigation/drainage system to treat two patients with post-surgical cerebral ventriculitis and a patient with bacterial meningitis complicated with ventriculitis. In this case series, we discuss the management of these three cases of cerebral ventriculitis: we monitored cytochemical parameters and cultures of the cerebrospinal fluid of patients during their ICU stay and we observed a marked improvement after irrigation and drainage with IRRAflow® system. Irrigation/drainage catheter stay, mode settings, and antibiotic therapies were different among these three patients, and neurological outcomes were variable, according to their underlying pathologies. IRRAflow® system can be applied also in other types of brain injury, such as intraventricular hemorrhage, intracranial abscess, subdural hematomas, and intracerebral hemorrhage, with the aim to remove the hematic residues and enhance the functional recovery of the patients. IRRAflow® seems a promising and useful tool to treat infectious and hemorrhagic diseases in neuro-intensive care unit.

Bacterial ventriculoperitoneal shunt infections: changing trends in antimicrobial susceptibility, a 7-year retrospective study from Pakistan

BACKGROUND

Ventriculoperitoneal (VP) shunt infections in adults represent a severe complication and make treatment more challenging. Therefore, drug susceptibility patterns are crucial for therapeutic decisions and infection control in neurosurgical centers. This 7-year retrospective study aimed to identify the bacteria responsible for adult VP shunt infections and determine their drug susceptibility patterns.

METHODS

This single-center study was performed from 2015 to 2021 in Lahore, Pakistan, and included CSF cultures from VP shunt infections. Demographic data, causative organisms, and antimicrobial susceptibility testing results were collected. Multivariate analysis of variance (MANOVA) and two-sample t-tests were used to analyze and compare the antibiotic sensitivity trends over the study period.

RESULTS

14,473 isolates recovered from 13,937 CSF samples of VP shunt infections were identified and analyzed for their susceptibility patterns to antimicrobials. The proportion of Gram-negative and Gram-positive bacteria were 11,030 (76%) and 3443 (24)%, respectively. The predominant bacteria were Acinetobacter species (n = 5898, 41%), followed by Pseudomonas species (n = 2368, 16%) and coagulase-negative Staphylococcus (CoNS) (n = 1880, 13%). 100% of Staphylococcus aureus (S.aureus) and CoNS were sensitive to vancomycin and linezolid (n = 2580). However, 52% of S. aureus (719/1,343) were methicillin-resistant Staphylococcus aureus (MRSA). Acinetobacter showed maximum sensitivity to meropenem at 69% (2759/4768). Pseudomonas was 80% (1385/1863 sensitive to piperacillin-tazobactam, Escherichia coli (E. coli) showed 72% to amikacin (748/1055), while Klebsiella spp. was 57% (574/1170) sensitive to piperacillin-tazobactam. The sensitivity of piperacillin-tazobactam and meropenem for Gram-negative bacteria decreased significantly (p < 0.05) over 7 years, with 92.2% and 88.91% sensitive in 2015 and 66.7% and 62.8% sensitive in 2021, respectively.

CONCLUSION

The significant decrease in the effectiveness of carbapenem and beta-lactam/beta-lactamase inhibitor combination drugs for the common Gram-negative causative agents of VP shunt infections suggests that alternative antibiotics such as colistin, fosfomycin, ceftazidime/avibactam, ceftolozane/tazobactam, and tigecycline should be considered and in consequence included in testing panels. Additionally, it is recommended to adopt care bundles for the prevention of VP shunt infection.

Clinical Experience with Off-Label Intrathecal Administration of Selected Antibiotics in Adults: An Overview with Pharmacometric Considerations

Drain-associated intracerebral infections are life-threatening emergencies. Their treatment is challenging due to the limited penetration of antibiotics to the site of infection, resulting in potentially inadequate exposure. The emergence of multidrug-resistant pathogens might force the use of off-label intrathecal (IT) doses of antibiotics. We reviewed the literature on general aspects determining intrathecal dosing regimen, using pharmacometric knowledge. We summarised clinical experience with IT doses of antibiotics that are usually not used intrathecally, as well as the outcome of the cases and concentrations reached in the cerebrospinal fluid (CSF). Factors determining the IT regimen are the size of the ventricle system and the CSF drainage volume. With regard to pharmacometrics, pharmacokinetic/pharmacodynamic indices are likely similar to those in non-cerebral infections. The following number (N) of cases were described: benzylpenicillin (>50), ampicillin (1), ceftazidime (2), cephaloridine (56), ceftriaxone (1), cefotiam (1), meropenem (57), linezolid (1), tigecycline (15), rifampicin (3), levofloxacin (2), chloramphenicol (3) and daptomycin (8). Many side effects were reported for benzylpenicillin in the 1940-50s, but for the other antibiotics, when administered correctly, all side effects were minor and reversible. These data might help when choosing an IT dosing regimen in case there is no alternative option due to antimicrobial resistance.

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.

Healthcare-associated central nervous system infections

PURPOSE OF REVIEW

The aim of this review is to provide a practical and updated summary on healthcare-associated central nervous system infections and their management.

RECENT FINDINGS

The term 'healthcare-associated ventriculitis and meningitis' has recently been coined and clinical practical guidelines have been published on the management of these nosocomial infections. Many aspects have still to be further investigated (e.g. cerebrospinal fluid biomarkers, indications for novel antibiotics, intrathecal antimicrobial regimens).

SUMMARY

Clinicians should maintain a high index of suspicion for healthcare-associated central nervous system infections in patients with specific risk factors (i.e. recent neurosurgery, cerebrospinal shunts, drains or implantable devices, head/spinal traumatic events), taking into account systemic signs, and alterations in microbiological, imaging, cerebrospinal fluid findings. The diagnosis is often difficult to confirm because of reduced levels of consciousness or coma. Both Gram-positive and Gram-negative (often multidrug-resistant or even pandrug-resistant) microorganisms may be the cause. Selection of antibiotics must consider susceptibility and penetration into the central nervous system. Ineffective treatments are frequent, and mortality can reach 60%. Future research should focus on the diagnostic performance of biomarkers and on the use of novel antimicrobial regimens, especially for the treatment of difficult to treat infections.

Brain Abscess with Pyogenic Ventriculitis

The authors present the case of a 57-year-old male with a large polymicrobial brain abscess complicated by eruption into the intraventricular space. He was treated with parenteral ampicillin, cefepime, and metronidazole and adjuvant intraventricular vancomycin/gentamicin as well as surgical debridement. The authors discuss the diagnosis, treatment, and prognosis of brain abscesses, with a focus on prior cases with pyogenic ventriculitis and those treated with intraventricular antimicrobials.

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.

Continuous intraventricular vancomycin for treatment of ventriculitis using IRRAflow®: A case report

Background

Ventriculitis usually occurs as the result of infection and results in the inflammation of the ependymal lining of the ventricular system. Mortality rates remain high despite treatment.

Case Description

We present the case of a 66-year-old man who presented with altered mental status and progressively became comatose. He was found to have fulminant ventriculitis due to a ruptured intracranial abscess. He was treated with bilateral IRRAflow® catheter (IRRAS, Stockholm, Sweden) placement through which continuous irrigation with vancomycin was initiated.

Conclusion

This treatment was safe and led to improvement in the patient's neurologic examination, imaging findings, and cerebrospinal fluid profiles.

Risk Factors Promoting External Ventricular Drain Infections in Adult Neurosurgical Patients at the Intensive Care Unit-A Retrospective Study

Objectives: Multiple risk factors have been described to be related to external ventricular drain (EVD) associated infections, with results varying between studies. Former studies were limited by a non-uniform definition of EVD associated infection, thus complicating a comparison between studies. In this regard, we assessed risk factors promoting EVD associated infections and propose a modified practice-oriented definition of EVD associated infections.

Methods: We performed a retrospective, single-center study on patients who were treated with an EVD, at the neurosurgical intensive care unit (ICU) at a tertiary center between 2008 and 2019. Based on microbiological findings and laboratory results, patients were assigned into an infection and a non-infection group. Patient characteristics and potential risk factors were compared between the two groups (p < 0.05). Receiver operating characteristics (ROC) for significant clinical, serum laboratory and cerebrospinal fluid (CSF) parameters were calculated.

Results: In total, 396 patients treated with an EVD were included into the study with a mean age of 54.3 (range: 18–89) years. EVD associated infections were observed in 32 (8.1%) patients. EVD insertion at another hospital (OR 3.86), and an increased CSF sampling frequency of more than every third day (OR 12.91) were detected as major risk factors for an EVD associated infection. The indication for EVD insertion, surgeon's experience, the setting of EVD insertion (ICU vs. operating room) and the operating time did not show any significant differences between the two groups. Furthermore, ROC analysis showed that clinical, serum laboratory and CSF parameters did not provide specific prediction of EVD associated infections (specificity 44.4%). This explains the high overtreatment rate in our cohort with the majority of our patients who received intrathecal vancomycin (63.3%), having either negative microbiological results (n = 12) or were defined as contaminations (n = 7).

Conclusions: Since clinical parameters and blood analyzes are not very predictive to detect EVD associated infections in neurosurgical patients, sequential but not too frequent microbiological and laboratory analysis of CSF are still necessary. Furthermore, we propose a uniform classification for EVD associated infections to allow comparability between studies and to sensitize the treating physician in determining the right treatment.

Inflammatory hydrocephalus

Reparative inflammation is an important protective response that eliminates foreign organisms, damaged cells, and physical irritants. However, inappropriately triggered or sustained inflammation can respectively initiate, propagate, or prolong disease. Post-hemorrhagic (PHH) and post-infectious hydrocephalus (PIH) are the most common forms of hydrocephalus worldwide. They are treated using neurosurgical cerebrospinal fluid (CSF) diversion techniques with high complication and failure rates. Despite their distinct etiologies, clinical studies in human patients have shown PHH and PIH share similar CSF cytokine and immune cell profiles. Here, in light of recent work in model systems, we discuss the concept of "inflammatory hydrocephalus" to emphasize potential shared mechanisms and potential therapeutic vulnerabilities of these disorders. We propose that this change of emphasis could shift our thinking of PHH and PIH from a framework of life-long neurosurgical disorders to that of preventable conditions amenable to immunomodulation.

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.

Epidemiology of patients with central nervous system infections, mainly neurosurgical patients: a retrospective study from 2012 to 2019 in a teaching hospital in China

BACKGROUND

Central nervous system (CNS) infections are relatively rare but are associated with high mortality worldwide. Empirical antimicrobial therapy is crucial for the survival of patients with CNS infections, and should be based on the knowledge of the pathogen distribution and antibiotic sensitivities. The aim of this study was to investigate the features of pathogens in patients with CNS infections in North China and evaluate the risk factors for mortality and multi-drug-resistant (MDR) bacterial infections.

METHODS

A retrospective study was conducted with patients with positive cerebrospinal fluid (CSF) cultures in a teaching hospital from January 2012 to December 2019. The following data were collected: demographic characteristics, laboratory data, causative organisms and antimicrobial sensitivity results. Data were analyzed with SPSS 16.0. Univariate analysis and binary logistic regression analyses were performed to identify the risk factors for mortality and MDR bacterial infections.

RESULTS

A total of 72 patients were diagnosed with CNS infections, and 86 isolates were identified. The proportions of Gram-positive bacteria, Gram-negative bacteria and fungi were 59.3, 30.2 and 10.5%, respectively. The predominant Gram-positive bacteria was Coagulase-negative Staphylococci. Acinetobacter baumannii, Escherichia coli and Klebsiella spp. were the predominant Gram-negative bacteria. Compared to 2012-2015 years, the proportion of Gram-negative bacteria increased markedly during 2016-2019 years. Coagulase-negative Staphylococci, Streptococcus pneumoniae and Enterococcus faecium had 100% sensitivity to vancomycin, teicoplanin and linezolid. Acinetobacter baumannii and Klebsiella pneumoniae were 100% sensitive to tigecycline. Escherichia coli had 100% sensitivity to amikacin, meropenem and imipenem. The overall mortality rate in the 72 patients was 30.6%. In multivariate analysis, age > 50 years, pulmonary infections and CSF glucose level < the normal value were associated with poor outcomes. CSF adenosine deaminase level > the normal value and the presence of external ventricular drainage/lumbar cistern drainage were associated with MDR bacterial infections.

CONCLUSIONS

The mortality rate due to CNS infections reached 30.6% in our study. The proportion of Gram-negative bacteria has increased markedly in recent years. We should give particular attention to patients with risk factors for mortality and MDR bacterial infections mentioned above.

Primary Nocardia brain abscesses and role of intraventricular antibiotic therapy

Intracranial infections caused by Nocardia Farcinica are challenging to treat and potentially lethal because of the organism's tendency to resist antibiotics and high relapse rates. Such infections usually occur in immunocompromised patients who have predisposing factors. Nocardia brain abscesses carry a higher morbidity and mortality rate than other bacterial brain abscesses, with reported mortality rates of 55% (even up to 90% in cases of late diagnosis) in immunocompromised patients. An aggressive therapeutic approach is required and an early identification of the microorganism is paramount. Given the high microbial resistance, it is usually an infection with a low cure rate. We present the case of a patient with primary brain abscesses due to Nocardia Farcinica, successfully treated with intrathecal Amikacin administration through ventricular drain, in addition to surgical evacuation and intravenous antibiotic therapy. In this case, clinical and radiological improvement were observed once the intrathecal treatment was started. To our best knowledge, no cases of intraventricular use of Amikacin have been previously reported to treat this type of infection and we believe that it may be useful in properly selected patients.

Ventriculitis: A Severe Complication of Central Nervous System Infections

BACKGROUND

Ventriculitis, a dreaded complication of brain abscess, meningitis, and various neurosurgical procedures, has attracted limited attention in the medical literature.

METHODS

This is a retrospective, single-center study. We screened the medical files of all patients who had a brain imaging report that included the word "ventriculitis" during years 2005-2019. Only patients with clinical, microbiological, and imaging features of ventriculitis were included. Data were collected through a standardized questionnaire.

RESULTS

Ninety-eight patients fulfilled inclusion criteria: 42 women and 56 men, and the median age was 60 years (interquartile range, 48-68). The primary mechanism for ventriculitis was classified as follows: brain abscess (n = 29, 29.6%), meningitis (n = 27, 27.6%), intraventricular catheter-related (n = 17, 17.3%), post-neurosurgery (n = 13, 13.3%), and hematogenous (n = 12, 12.2%). The main neuroimaging features were intraventricular pus (n = 81, 82.7%), ependymal enhancement (n = 70, 71.4%), and intraventricular loculations (n = 15, 15.3%). The main pathogens were streptococci (n = 44, 44.9%), Gram-negative bacilli (n = 27, 27.6%), and staphylococci (n = 15, 15.3%). In-hospital and 1-year mortality rates were 30.6% (n = 30) and 38.8% (n = 38), respectively. Neurological sequelae were reported in 34 of 55 (61.8%) survivors, including cognitive impairment (n = 11), gait disturbances (n = 9), paresis (n = 7), behavior disorder (n = 6), and epilepsy (n = 5). On multivariate analysis, age >65 years, Glasgow Coma Scale score <13 at initial presentation, status epilepticus, hydrocephalus, and positive cerebrospinal fluid culture were associated with 1-year mortality. We built a scoring system to stratify patients with ventriculitis into low risk (12.5%), intermediate risk (36.5%), and high risk (71.4%) of death.

CONCLUSIONS

Ventriculitis is a severe complication of brain abscess, meningitis, or neurosurgery, with an in-hospital mortality rate of 30% and neurological sequelae in 60% of survivors.

The role of intraventricular antibiotic therapy in the treatment of ventriculo-peritoneal shunt infection in children

BACKGROUND

In this study, the effectiveness of intraventricular (IVT) antibiotic administration was evaluated in the treatment of ventriculo-peritoneal (VP) shunt infection by comparing patients who received only systemic antibiotic treatment with patients who received antibiotics added to systemic therapy by IVT route.

METHODS

From July 2009 to July 2019, 78 shunt infection episodes of 74 pediatric patients with bacterial growth in cerebrospinal fluid (CSF) culture who were treated with the diagnosis of VP shunt infection were retrospectively analyzed. The demographic data, clinical and laboratory parameters, antimicrobial management, and treatment outcomes of patients with VP shunt infections were recorded.

RESULTS

Thirty-eight of 78 shunt episodes received only systemic antibiotic treatment, and 40 had received IV plus IVT treatment. The mean age of the entire patient group was 16.7±21.3 months (range, 1 to 95 months). There was no significant difference between the two treatment groups in terms of mean age. The most common microorganism grown in CSF culture was coagulase-negative Staphylococcus. However, in the group that received IV plus IVT treatment, gram-negative bacteria were predominant (42.1% versus 20%), and this group had carbapenem-resistant and ESBL positive gram-negative bacteria growth. In the duration of CSF sterilization, hospital stay was statistically significantly shorter in the group receiving IV plus IVT treatment (p=0.000, p=0.000, respectively).

CONCLUSION

Our study shows that IVT administration of antibiotics shortens the duration of CSF sterilization, duration of antibiotic use, and the duration of hospital stay. For the treatment of VP shunt infection, the usage of IVT treatment in a particular group of a pediatric age is promising. However, further efforts should be done for supporting the current results by randomized controlled studies.

Pharmacokinetics of colistin in cerebrospinal fluid after intraventricular administration alone in intracranial infections

The aim of this study was to investigate the pharmacokinetics of colistin in cerebrospinal fluid (CSF) after intraventricular (IVT) administration of colistin methanesulfonate (CMS) for central nervous system (CNS) infections caused by multidrug-resistant Gram-negative bacteria. Ten patients with CNS infection were treated with CMS (active substance colistin equivalent to 100 000 units, every 24 h) by IVT administration. After 3 days of treatment, the concentration of colistin in the CSF was determined by selective ultra-performance liquid chromatography (UPLC) at 2, 4, 6, 8, 12 and 24 h after CMS administration. A pharmacokinetic analysis was performed using Phoenix WinNonlin. Following IVT administration of CMS, the estimated colistin apparent CSF half-life (t_1/2) was 10.46 ± 6.98 h, the average peak colistin concentration (C_max) was 16.95 ± 7.39 μg/mL and the average time to peak concentration (T_max) was 4.6 ± 0.97 h. The measured trough concentration (C_min; colistin concentration in CSF at 24 h after administration of CMS) was 1.12-8.33 μg/mL and the average C_min was 2.91 ± 2.11 μg/mL. CSF concentrations of colistin were above the minimum inhibitory concentration (MIC) of 0.5 μg/mL at 24 h after IVT administration in all patients. Microbiological cure was observed in all patients. In conclusion, this is the first study of colistin pharmacokinetics in CSF after IVT administration alone in patients with CNS infection. It provides essential data for designing relatively safe and effective CMS dosing regimens.

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.

Intraventricular Plus Intravenous Tigecycline for the Treatment of Daptomycin Nonsusceptible Vancomycin-Resistant Enterococci in an Infant with Ventriculoperitoneal Shunt Infection

BACKGROUND

Ventriculoperitoneal (VP) shunt infection, which is 1 of the most important complications of VP shunt is observed at a rate of 4%-17%. Staphylococcus epidermidis is the most common causative agent. Vancomycin-resistant Enterococcus (VRE) is an increasingly common nosocomial pathogen that rarely causes central nervous system infections globally. Current treatment options that have shown appreciable activity against various VRE infections include daptomycin, linezolid, inquinupristin/dalfopristin, and tigecycline. Daptomycin has a particular mode of action and a potent bactericidal activity, making it a useful addition to the clinician's antibiotic collection. Global surveillance data indicate <1.0% rates of daptomycin resistance in enterococci.

CASE DESCRIPTION

Here, we describe, to the best of our knowledge, the first case of successful intraventricular plus intravenous use of tigecycline to treat VP shunt infections caused by daptomycin resistant VRE faecium.

CONCLUSION

Tigecycline is a life-saving option in the treatment of resistant nosocomial infections but it has not yet been approved for use and there are not enough data in terms of dose and side effects associated with its use in children.

Use of ventriculostomy in the treatment of septic cavernous sinus thrombosis (SCST)

We present a novel treatment with the use of intraventricular antibiotics delivered through a ventriculostomy in a patient who developed septic cavernous sinus thrombosis after sinus surgery. A 65-year-old woman presented with acute on chronic sinusitis. The patient underwent a diagnostic left maxillary antrostomy, ethmoidectomy, sphenoidotomy and sinusotomy. Postoperatively, the patient experienced altered mental status with episodic fever despite treatment with broad-spectrum antimicrobial therapy. MRI of the brain showed extensive meningeal enhancement with the involvement of the right trigeminal and abducens nerve along with thick enhancement along the right pons and midbrain. MR arteriogram revealed a large filling defect within the cavernous sinus. Intraventricular gentamicin was administered via external ventricular drain (ie, ventriculostomy) every 24 hours for 14 days with continued treatment of intravenous ceftriaxone and metronidazole. The patient improved with complete resolution of her cavernous sinus meningitis on repeat brain imaging at 6 months posthospitalisation.