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

Therapeutic drug monitoring of polymyxin B cerebrospinal fluid concentrations in patients with carbapenem-resistant Gram-negative bacteria-induced central nervous system infection

OBJECTIVES

Central nervous system (CNS) infections caused by carbapenem-resistant Gram-negative bacteria (CR-GNB) present a major health and economic burden worldwide. This multicentre prospective study aimed to assess the feasibility and usefulness of CSF therapeutic drug monitoring (TDM) after intrathecal/intraventricular administration of polymyxin B in patients with CNS infections.

METHODS

Forty-two patients treated with intrathecal/intraventricular administration of polymyxin B against CR-GNB-induced CNS infections were enrolled. CSF trough level (Cmin) was collected beginning on Day 2 post-polymyxin B initiation and thereafter. The primary outcomes were clinical cure and 28-day all-cause mortality.

RESULTS

All patients started with intrathecal/intraventricular administration of polymyxin B at a dose of 5 g/day, corresponding to a median CSF Cmin of 2.93 mg/L (range, 0.21-25.74 mg/L). Clinical cure was 71.4%, and the median CSF Cmin of this group was higher than that of clinical failure group [3.31 (IQR, 1.73-5.62) mg/L versus 2.25 (IQR, 1.09-4.12) mg/L; P = 0.011]. In addition, with MICs ≤ 0.5 mg/L, maintaining polymyxin B CSF Cmin above 2.0 mg/L showed a higher clinical cure rate (P = 0.041). The 28-day all-cause mortality rate was 31.0% and had no association with CSF Cmin.

CONCLUSIONS

After intrathecal/intraventricular administration of polymyxin B, CSF concentrations fluctuated considerably inter- and intra-individual. Polymyxin B CSF Cmin above 2.0 mg/L was associated with clinical cure when MICs were ≤ 0.5 mg/L, and the feasibility of TDM warrants additional clinical studies.

Modified ventriculoperitoneal shunt applied to temporary external ventricular drainage

External ventricular drainage (EVD) is a common procedure in neurosurgical practice. Presently, the three methods used most often include direct EVD (dEVD), long-tunneled external ventricular drains (LTEVDs), and EVD via the Ommaya reservoir (EVDvOR). But they possess drawbacks such as limited duration of retention, vulnerability to iatrogenic secondary infections, and challenges in regulating drainage flow. This study aimed to explore the use of a modified ventriculoperitoneal shunt (mVPS)-the abdominal end of the VPS device was placed externally-as a means of temporary EVD to address the aforementioned limitations. This retrospective cohort study, included 120 cases requiring EVD. dEVD was performed for 31 cases, EVDvOR for 54 cases (including 8 cases with previously performed dEVD), and mVPS for 35 cases (including 6 cases with previously performed EVDvOR). The one-time success rate (no need for further other EVD intervention) for dEVD, EVDvOR, and mVPS were 70.97%, 88.89%, and 91.42%, dEVD vs EVDvOR (P < 0.05), dEVD vs mVPS (P < 0.05), EVDvOR vs mVPS (P > 0.05). Puncture needle displacement or detachment was observed in nearly all cases of EVDvOR, while no such complications have been observed with mVPS. Apart from this complication, the incidence of postoperative complications was 35.48%, 14.81%, and 8.5%, dEVD vs EVDvOR (P < 0.05), dEVD vs mVPS (P < 0.05), EVDvOR vs mVPS (P > 0.05). Mean postoperative retention for EVD was 14.68 ± 9.50 days, 25.96 ± 15.14 days, and 82.43 ± 64.45 days, respectively (P < 0.001). In conclusion, mVPS significantly extends the duration of EVD, which is particularly beneficial for patients requiring long-term EVD.

Intrathecal or intraventricular antimicrobial therapy for post-neurosurgical Gram-negative bacillary meningitis or ventriculitis: a systematic review and meta-analysis

PURPOSE

Extensively-drug-resistant Gram-negative bacteria (XDR GNB)-related post-neurosurgical infection is closely related to mortality, which represents a major challenge for neurosurgeons. There is an urgent need to review and evaluate methods to reduce mortality.

METHODS

Both international and Chinese databases were searched independently from their inception to 15 June 2023. A meta-analysis was conducted using RevMan 5.4 to compare the efficacy and safety of intravenous (IV) treatment in combination with intrathecal or intraventricular (ITH/IVT) treatment with IV treatment alone for post-neurosurgical meningitis or ventriculitis due to GNB. Mortality, microbiological clearance and adverse events were considered as primary outcomes.

RESULTS

In total, 18 eligible studies involving 602 patients were included in the meta-analysis. The IV + ITH/IVT group was associated with significantly lower mortality (especially in the XDR GNB subgroup) and acceptable safety. In terms of microbiological clearance, a significant decrease was shown in the XDR GNB subgroup. Significant benefits were shown in laboratory parameters and clinical symptoms after patients were treated with ITH/IVT.

CONCLUSION

Additional ITH/IVT treatment may promote XDR GNB clearance and reduce mortality. In addition, ITH/IVT administration can improve clinical symptoms and cerebrospinal fluid indicators of patients with post-neurosurgical infections. Significantly, ITH/IVT treatment does not increase the incidence of adverse events at the recommended dose.

Clinical and microbiological characteristics of carbapenem-resistant Enterobacteriaceae causing post-operative central nervous system infections in China

OBJECTIVES

Postoperative central nervous system infections (PCNSIs) caused by carbapenem-resistant Enterobacteriaceae (CRE) frequently result in unfavourable outcomes. However, CRE PCNSIs have not been well described from a clinical and microbiological perspective.

METHODS

A total of 254 PCNSIs cases were included (January 2017 through June 2020), and clinical features were compared based on pathogenic classification. Cox regression analysis was performed to assess risk factors for mortality. Antibiotic susceptibility testing and whole genome sequencing were conducted on CRE isolates preserved. MLST, cgMLST, resistance genes and virulence genes were further analysed.

RESULTS

Among 254 PCNSI cases, 15.4% were caused by Enterobacteriaceae including 28 cases by CRE. The 28-day mortality rates for CRE, CSE and non-Enterobacteriaceae PCNSIs were 50.0%, 27.3%, and 7.4%, respectively. 42.9% (12/28) of the CRE PCNSIs patients achieved clinical cure, with 25.0% achieved microbiological clearance. ST11-KL64 carrying blaKPC-2 was dominant in CRE (17/23, 73.9%), and the 28-day mortality rate of its infection was 58.5%. Most CRKP carried rampA/rampA2 genes (17/23, 73.9%).

CONCLUSION

ST11-KL64 CRKP carrying blaKPC-2 dominated among CRE PCNSIs. Targeted anti-infective combination therapy based on ceftazidime/avibactam or amikacin, combined with intrathecal administration of amikacin, was found to be effective. These findings render a new insight into the clinical and microbiological landscape of CRE PCNSIs.

Treatment and prognostic risk factors for intracranial infection after craniocerebral surgery

The objective of this study was to determine risk factors of pejorative evolution course in patients suffering from postoperative cranial infection. The data of patients who developed an intracranial infection after craniocerebral surgery in the neurosurgical intensive care unit of the First Affiliated Hospital of Nanjing Medical University in Nanjing, Jiangsu, China, from February 2018 to August 2019 were retrospectively analyzed. Logistic regression was used to analyze the factors influencing the prognosis of intracranial infection treatment. Sixty-four patients developed an infection after craniocerebral surgery, and 48 of them with negative CSF cultures received experimental anti-infectives. In 16 patients, cerebrospinal fluid culture showed pandrug-resistant pathogens, including 11 Acinetobacter baumannii (11), Klebsiella pneumoniae (3), Escherichia coli (1), and Candida glabrata (1). Nine patients received intraventricular or intrathecal injections of polymyxin B. The mean duration of infection treatment was 22.2 ± 9.9 days, and the clinical cure rate was 85.9% (55/64). Logistic multivariate regression analysis showed that inadequate CSF drainage (OR, 6.839; 95% CI, 1.130-41.383; P = 0.036) and infection with drug-resistant bacteria (OR, 24.241; 95% CI, 2.032-289.150; P = 0.012) were independent risk factors for postoperative intracranial infection. Intracranial infection with positive CSF culture and inadequate CSF drainage are factors contributing to the poor prognosis of intracranial infection. Moreover, early anti-infection treatment and adequate CSF drainage may improve patient outcomes. In particular, intraventricular or intrathecal injection of polymyxin B may be a safe and effective treatment strategy for MDR/XDR gram-negative bacilli infection.

The Blood-Brain Barrier and Pharmacokinetic/Pharmacodynamic Optimization of Antibiotics for the Treatment of Central Nervous System Infections in Adults

Bacterial central nervous system (CNS) infections are serious and carry significant morbidity and mortality. They encompass many syndromes, the most common being meningitis, which may occur spontaneously or as a consequence of neurosurgical procedures. Many classes of antimicrobials are in clinical use for therapy of CNS infections, some with established roles and indications, others with experimental reporting based on case studies or small series. This review delves into the specifics of the commonly utilized antibacterial agents, updating their therapeutic use in CNS infections from the pharmacokinetic and pharmacodynamic perspectives, with a focus on the optimization of dosing and route of administration that have been described to achieve good clinical outcomes. We also provide a concise synopsis regarding the most focused, clinically relevant information as pertains to each class and subclass of antimicrobial therapeutics. CNS infection morbidity and mortality remain high, and aggressive management is critical in ensuring favorable patient outcomes while averting toxicity and upholding patient safety.

Prediction of Intracranial Infection in Patients under External Ventricular Drainage and Neurological Intensive Care: A Multicenter Retrospective Cohort Study

Objective: To generate an optimal prediction model along with identifying major contributors to intracranial infection among patients under external ventricular drainage and neurological intensive care. Methods: A retrospective cohort study was conducted among patients admitted into neurointensive care units between 1 January 2015 and 31 December 2020 who underwent external ventricular drainage due to traumatic brain injury, hydrocephalus, and nonaneurysmal spontaneous intracranial hemorrhage. Multivariate logistic regression in combination with the least absolute shrinkage and selection operator regression was applied to derive prediction models and optimize variable selections. Other machine-learning algorithms, including the support vector machine and K-nearest neighbor, were also applied to derive alternative prediction models. Five-fold cross-validation was used to train and validate each model. Model performance was assessed by calibration plots, receiver operating characteristic curves, and decision curves. A nomogram analysis was developed to explicate the weights of selected features for the optimal model. Results: Multivariate logistic regression showed the best performance among the three tested models with an area under curve of 0.846 ± 0.006. Six variables, including hemoglobin, albumin, length of operation time, American Society of Anesthesiologists grades, presence of traumatic subarachnoid hemorrhage, and a history of diabetes, were selected from 37 variable candidates as the top-weighted prediction features. The decision curve analysis showed that the nomogram could be applied clinically when the risk threshold is between 20% and 100%. Conclusions: The occurrence of external ventricular-drainage-associated intracranial infections could be predicted using optimal models and feature-selection approaches, which would be helpful for the prevention and treatment of this complication in neurointensive care units.

Outcome of Using Intraventricular Plus Intravenous Polymyxin B in Post-neurosurgical Patients With Multi/Extensively Drug-Resistant Gram-Negative Bacteria-Induced Intracranial Infection

Introduction

Post-neurosurgical central nervous system (CNS) infection caused by multidrug-resistant (MDR)/extensively drug-resistant (XDR) Gram-negative bacteria remains a major clinical challenge. This study describes our experience of treating such patients with combined intraventricular (IVT) and intravenous (IV) polymyxin B administration.

Methods

This retrospective study included six patients with post-neurosurgical CNS infections of carbapenem-resistant Acinetobacter baumannii (CRAB) or carbapenem-resistant Klebsiella pneumoniae (CRKP). All patients were treated in the intensive care unit (ICU) of First Affiliated Hospital, Zhejiang University School of Medicine (Hangzhou, China) between November 2020 and November 2021, and all received IVT plus IV polymyxin B. Data including patients' characteristics, therapeutic process, symptoms, cerebrospinal fluid (CSF) examination, laboratory tests, and complications were collected.

Results

Six patients with post-neurosurgical CNS infection were enrolled in the study. The patients comprised five males and one female, and the average age was 58 years (range, 38–73 years). Four out of the six cases were CRAB-positive in CSF culture, while two cases were CRKP-positive. The mean duration of polymyxin B administration was 14 ± 5.69 days (range, 6–20 days). The average period of patients reaching CSF sterilization was 10.33 ± 3.67 days (range, 5–14 days). All six cases were cured without acute kidney injury or epilepsy.

Conclusion

IVT plus IV polymyxin B is a safe and effective treatment for post-neurosurgical patients with intracranial infection caused by MDR/XDR Gram-negative bacteria.

Pharmacokinetics and pharmacodynamics of peptide antibiotics

Antimicrobial resistance is a major global health challenge. As few new efficacious antibiotics will become available in the near future, peptide antibiotics continue to be major therapeutic options for treating infections caused by multidrug-resistant pathogens. Rational use of antibiotics requires optimisation of the pharmacokinetics and pharmacodynamics for the treatment of different types of infections. Toxicodynamics must also be considered to improve the safety of antibiotic use and, where appropriate, to guide therapeutic drug monitoring. This review focuses on the pharmacokinetics/pharmacodynamics/toxicodynamics of peptide antibiotics against multidrug-resistant Gram-negative and Gram-positive pathogens. Optimising antibiotic exposure at the infection site is essential for improving their efficacy and minimising emergence of resistance.

Intrathecal Injection of Tigecycline and Polymyxin B in the Treatment of Extensively Drug-Resistant Intracranial Acinetobacter baumannii Infection: A Case Report and Review of the Literature

Purpose

Intracranial infection after neurosurgery is one of the most serious complications, especially extensively drug-resistant (XDR) Acinetobacter baumannii (A. baumannii) seriously affects the prognosis of patients. At present, there is little experience in the treatment of this infection and limited effective treatment options, like tigecycline or polymyxin B. Therefore, this report aims to describe the efficacy of tigecycline combined with polymyxin B by intrathecal (ITH) injection in the treatment of XDR intracranial infection with A. baumannii.

Methods

We report a case of intracranial infection with XDR A. baumannii after ventricular drainage, treated by daily ITH and intravenous (IV) tigecycline, combined with polymyxin B ITH route. Moreover, tigecycline and polymyxin B treatments for XDR intracranial infection with A. baumannii that were reported in the literature were also reviewed and summarized.

Results

The white blood cells (WBCs) of the patient’s cerebrospinal fluid dropped to normal, and the symptoms of intracranial infection disappeared. The patient finally obtained good clinical results and transferred to the local hospital.

Conclusion

The polymyxin B ITH route is an ideal treatment strategy for XDR A. baumannii. The IV plus ITH tigecycline may be an effective treatment option. However, more researches should be conducted to confirm our observation.

Successful Treatment of Severe Post-craniotomy Meningitis Caused by an Escherichia coli Sequence Type 410 Strain Coharboring bla NDM - 5 and bla CTX - M - 65

Intracranial infections caused by multidrug-resistant Gram-negative bacterium have led to considerable mortality due to extremely limited treatment options. Herein, we firstly reported a clinical carbapenem-resistant Escherichia coli isolate coharboring bla NDM - 5 and bla CTX - M - 65 from a patient with post-craniotomy meningitis. The carbapenem-resistant Escherichia coli strain CNEC001 belonging to Sequence Type 410 was only susceptible to amikacin and tigecycline, both of which have poor penetration through the blood-brain barrier (BBB). The bla CTX - M - 65 gene was expressed on a 135,794 bp IncY plasmid. The bla NDM - 5 gene was located on a genomic island region of an IncX3-type plasmid pNDM5-CNEC001. Based on the characteristics of the strain, we presented the successful treatment protocol of intravenous (IV) tigecycline and amikacin combined with intrathecal (ITH) amikacin in this study. Intracranial infection caused by Escherichia coli coharboring bla NDM - 5 and bla CTX - M - 65 is rare and fatal. Continuous surveillance and infection control measures for such strain need critical attention in clinical settings.

Central nervous system infections and antimicrobial resistance: an evolving challenge

PURPOSE OF REVIEW

Antimicrobial resistance is an increasing threat to patients also in nosocomial central nervous system (CNS) infections. The present review focusses on optimizing intravenous treatment in order to achieve sufficient concentrations of antibiotics in the different compartments of the CNS when the causative pathogens have reduced sensitivity to antibiotics or/and the impairment of the blood-cerebrospinal fluid (CSF) and blood-brain barrier is mild.

RECENT FINDINGS

Experience has been gathered with treatment protocols for several established antibiotics using increased doses or continuous instead of intermittent intravenous therapy. Continuous infusion in general does not increase the average CSF concentrations (or the area under the concentration-time curve in CSF) compared to equal daily doses administered by short-term infusion. In some cases, it is postulated that it can reduce toxicity caused by high peak plasma concentrations. In case reports, new β-lactam/β-lactamase inhibitor combinations were shown to be effective treatments of CNS infections.

SUMMARY

Several antibiotics with a low to moderate toxicity (in particular, β-lactam antibiotics, fosfomycin, trimethoprim-sulfamethoxazole, rifampicin, vancomycin) can be administered at increased doses compared to traditional dosing with low or tolerable adverse effects. Intrathecal administration of antibiotics is only indicated, when multiresistant pathogens cannot be eliminated by systemic therapy. Intravenous should always accompany intrathecal treatment.