Cerebrospinal fluid (CSF) pharmacokinetics of intraventricular vancomycin in patients with staphylococcal ventriculitis associated with external CSF drainage

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.

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.

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.

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.

A Systematic Review of Studies Reporting Antibiotic Pharmacokinetic Data in the Cerebrospinal Fluid of Critically Ill Patients with Uninflamed Meninges

Ventriculostomy-associated infections in critically ill patients remain therapeutically challenging because of drug- and disease-related factors that contribute to suboptimal antibiotic concentrations in cerebrospinal fluid. Optimal antibiotic dosing for the treatment and prevention of such infections should be based on robust and contextually specific pharmacokinetic data. The objects of this study were to describe and critically appraise studies with reported antibiotic concentrations or pharmacokinetic data in cerebrospinal fluid of critically ill patients without meningeal inflammation. We systematically reviewed the literature to identify published reports and studies describing antibiotic concentrations, pharmacokinetics, and pharmacokinetics/pharmacodynamics in cerebrospinal fluid of critically ill patients with uninflamed meninges. Fifty-eight articles met the inclusion criteria. There was significant heterogeneity in methodologies and results. When available, antibiotic pharmacokinetic parameters displayed large intersubject variability. Intraventricular dosing achieved substantially higher antibiotic concentrations in cerebrospinal fluid than did intravenous doses. Few studies conducted a robust pharmacokinetic analysis and described relevant clinical pharmacokinetic/pharmacodynamic indices and exposure targets in cerebrospinal fluid. Robust and clinically relevant antibiotic pharmacokinetic data describing antibiotic disposition in cerebrospinal fluid are necessary. Such studies should use a standardized approach to accurately describe pharmacokinetic variability. These data should ideally be tied to clinical outcomes whereby therapeutic targets in the cerebrospinal fluid can be better defined. Altered dosing strategies, in conjunction with exploring the utility of therapeutic drug monitoring, can then be developed to optimize antibiotic exposure with the goal of improving outcomes in this difficult-to-treat patient group.

The role of antibiotic pharmacokinetic studies performed post-licensing

Post-licensing pharmacometric studies can provide a better understanding of the pharmacokinetic (PK) alterations in special patient populations and may lead to better clinical outcomes. Some patient populations exhibit markedly different pathophysiology to general ward patients or healthy individuals. This may be developmental (paediatric patients), a manifestation of an underlying disease pathology (patients with obesity or haematological malignancies) or due to medical interventions (critically ill patients receiving extracorporeal therapies). This paper outlines the factors that affect the PK of special patient populations and describes some novel methods of antimicrobial administration that may increase antimicrobial concentrations at the site of infection and improve treatment of severe infection.

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.

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.

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.

Population Pharmacokinetics of Vancomycin in Postoperative Neurosurgical Patients and the Application in Dosing Recommendation

Our previous study indicates that cerebrospinal fluid (CSF) albumin level is a determinant of CSF vancomycin concentration for postoperative neurosurgical patients. We aimed to develop an improved vancomycin population pharmacokinetic model with incorporation of more covariates, and to provide dosing guidance for clinicians. Vancomycin was administered intravenously to 20 patients with external ventricular drains after neurosurgical operation. Blood and CSF were collected and vancomycin concentrations were measured by HPLC. A separate CSF compartment was considered, and was linked to the central compartment by a first-order process (Q_CSF). The clearance of the CSF compartment (Cl_CSF) was used to characterize vancomycin elimination from CSF through external ventricular drain. Nonlinear mixed-effects modeling approach was used to develop the model. The CSF albumin level (mg/dL) was the covariate influencing Q_CSF: Q_CSF=0.0049+0.000021×(CSF albumin-279). The effect of body weight (BW, kg) was significant on central volume (V_C): V_C=27.84+0.96×(BW-69). All parameters were estimated with an acceptable precision (relative standard error: RSE% < 30.26). The performance of the final model was acceptable with our previous dataset. A simple to use dosage regimen table was created to guide clinicians with vancomycin dosing. This model incorporates variables of both CSF albumin and BW, which offers improvements to the previous pharmacokinetics model.

Central Nervous System Infections in the Critically Ill

Central nervous system (CNS) infections are frequently encountered in the intensive care unit setting and are a significant source of morbidity and mortality. The constantly changing trends in microbial resistance, as well as the pharmacokinetic difficulties in providing effective concentrations of antimicrobials at the site of infection represent a unique challenge to clinicians. Achievement of a successful outcome in patientswith CNS infections is reliant on eradication of the offending pathogen and management of any neurologic complications. This requires an anatomic and physiologic understanding of the different types of CNS infection, diagnostic strategies, associated complications, causative organisms, and the principles that govern drug distribution into the CNS. This article serves as a review of the epidemiology, pathophysiology, diagnosis, and treatment options for a variety of CNS infections, with a focus on those commonly encountered in an intensive care setting.

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.

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.

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

PURPOSE OF REVIEW

The aim is to review the role of intraventricular administration of antimicrobial agents in the treatment of patients with bacterial and fungal meningitis.

RECENT FINDINGS

This article discusses indications for intraventricular antimicrobial agents, choice of antibiotics, strategies to monitor pharmacokinetics of central nervous system compartments and unanswered issues for this management approach.

SUMMARY

Intraventricular administration of antimicrobials may be necessary in certain difficult- to- eradicate central nervous system infections. There is a significant need for clinical trials and management guidelines in this area.

Antimicrobial therapy and local toxicity of intraventricular administration of vancomycin in a neonate with ventriculitis

Infection is the most common complication and cause of failure of cerebrospinal fluid (CSF) shunt devices used to control hydrocephalus. A male newborn was admitted for treatment of congenital occlusive hydrocephalus by means of a ventriculo-peritoneal shunt. A day later, the skin area around the site of insertion of ventriculo-peritoneal catheter was red and edematous. Intravenous ceftazidime and vancomycin were initiated. The shunt was removed but the external ventricular drain was preserved. Blood and CSF cultures showed Enterococcus faecalis sensitive to vancomycin, ciprofloxacin and gentamicin, but resistant to ampicillin. Intraventricular administration of vancomycin 10 mg/24 h was initiated through the external ventricular drain. Before the first dose of vancomycin intraventricularly, CSF levels were 19 mg/dL as a result of administration. On the third day of intraventricular dosing, vancomycin levels in CSF reached 388 mg/dL and protein levels were 1160 mg/dL. On the fifth day of intraventricular treatment the patient had clinically improved and was bacteriologically cured. However, in CSF, protein levels were 3300 mg/dL and vancomycin levels 201 mg/dL. In an attempt to prevent high and potentially toxic levels in CSF, the intraventricular dose of vancomycin should be individualized according to clinical response, bacteriological cultures, vancomycin levels in CSF, and surrogate markers of neurotoxicity, that is, eosinophilia and high protein levels in CSF.

Persistent and intractable ventriculitis due to retained ventricular catheters

It is generally recommended that, in cases of difficulty in removing a ventricular catheter during a shunt revision, it is best left alone to avoid intraventricular haemorrhage. Retained ventricular catheters (RVCs) are usually safe, although in the presence of ventriculitis they may become colonized by organisms and become a source of persistent or recurrent infection. The authors present a case of persistent and intractable ventriculitis due to an old retained ventricular catheter. A 23-year-old female, who had a RVC and a functioning shunt, was admitted for a suspected blocked shunt. At surgery the shunt was found to be infected and external drainage was instituted. Over the next 4 months, she developed intractable and persistent staphylococcal ventriculitis, despite undergoing 10 further surgical procedures, and appropriate intravenous and intrathecal antibiotic therapy. She responded rapidly only after surgical removal of the old RVC via a craniotomy. The staphylococcus cultured from the RVC had an identical antibiogram to the organism responsible for the intractable ventriculitis. This case emphasizes the point that, although RVC are generally considered safe, removal becomes imperative in the presence of concurrent CSF infection that fails to respond quickly to intrathecal antibiotic therapy.

Clinical experience with linezolid for the treatment of central nervous system infections

Linezolid, an oxazolidinone, exhibits bacteriostatic activity against virtually all Gram-positive bacteria and even covers atypical organisms like mycobacteria and Nocardia. However, little is known about its effectiveness for central nervous system (CNS) infections. We report on our good experience with linezolid for the treatment of CNS infections in 10 patients, amongst whom three were caused by mycobacteria. While six of our patients clinically improved during linezolid therapy even after failure of various antibiotics, it was unsuccessful in one case. Side-effects were only mild gastrointestinal problems in one patient after long term-treatment, which however led to the cessation of therapy. Linezolid appears to be a safe alternative to vancomycin for therapy-resistant CNS infections because of its good CSF penetration and few side-effects.

Antimicrobial agents in the treatment of bacterial meningitis

The use of antimicrobial agents in the treatment of acute bacterial meningitis has undergone significant changes in recent years. There is a wealth of in vitro and animal model data that support the use of the specific antimicrobial agents in the treatment of bacterial meningitis, although not all regimens have been evaluated in clinical trials. Recent investigations have focused on expanding the potential antimicrobial formulary to manage patients with bacterial meningitis effectively in this era of increasing antimicrobial resistance. Despite these advances, the morbidity and mortality of acute bacterial meningitis remain unacceptably high. The use of adjunctive dexamethasone has been shown to improve morbidity and mortality in patients with bacterial meningitis, although concerns have been raised that dexamethasone may reduce penetration of certain antimicrobial agents into cerebrospinal fluid.

Treatment of meningitis due to methicillin-resistant Staphylococcus epidermidis with linezolid

Methicillin-resistant Staphylococcus epidermidis (MRSE) can cause nosocomial meningitis in the presence of prosthetic devices. Vancomycin is the treatment of choice, but its penetration into the cerebrospinal fluid is poor, especially in cases without severe meningeal inflammation. We successfully used linezolid to treat a case of posttraumatic MRSE meningitis with a low-level inflammatory response. Therapeutic effectiveness was documented microbiologically and by the simultaneous measurement of linezolid levels in serum and cerebrospinal fluid.

Treatment of staphylococcal ventriculitis associated with external cerebrospinal fluid drains: a prospective randomized trial of intravenous compared with intraventricular vancomycin therapy

OBJECT

Staphylococcal ventriculitis may be a complication in temporary external ventricular drains (EVDs). The limited penetration of vancomycin into the cerebrospinal fluid (CSF) is well known; the pharmacodynamics and efficacy of systemically compared with intraventricularly administered vancomycin is examined in this prospective study.

METHODS

Ten patients in whom EVDs were implanted to treat intracranial hemorrhage and who were suffering from drain-associated ventriculitis were randomized into two treatment groups. Five of these patients (median age 47 years) were treated with 2 g/day vancomycin administered intravenously (four infusions/day, Group 1), and the other five(median age 49 years) received 10 mg vancomycin intraventricularly once daily (Group 2). Vancomycin levels were measured in serum and CSF six times a day. The maximum vancomycin level in CSF was 1.73 +/- 0.4 micro/ml in Group 1 and 565.58 +/- 168.71 microg/ml 1 hour after vancomycin application in Group 2 (mean +/- standard deviation). Vancomycin levels above the recommended trough level of 5 microg/ml in CSF were never reached in Group 1, whereas in Group 2 they below the trough level (3.74 +/- 0.66 microg/ml) only at 21 hours after intraventricular vancomycin application. The vancomycin level in the serum was constant within therapeutic levels in Group 1, whereas in Group 2 in most instances vancomycin was almost below a measurable concentration. In both groups bacteriologically and laboratory-confirmed CSF clearance could be obtained.

CONCLUSIONS

Intraventricular vancomycin application is a safe and efficacious treatment modality in drain-associated ventriculitis, with much higher vancomycin levels being achieved in the ventricular CSF than by intravenous administration.

The effect of netilmicin and vancomycin on lipid peroxidation processes in cerebrospinal fluid in children with hydrocephalus

In biological systems, it is difficult to determine free radicals because of their reactivity and their very short time of existence. On the basis of markers, which come into being as a result of radical processes, one might believe that there exist reactive oxygen species. One of the determinants of free radical activity of oxygen is the presence of malondialdehyde (MDA), a final product of lipid peroxidation. This study aimed at finding the answer to the question whether the concentration of netylmicin and vancomycin influences the amount of substances reacting with thiobarbituric acid (TBA) in cerebrospinal fluid (CSF) in children with hydrocephalus. Applying the TBA test for examinations with antibiotics added both in vivo and in vitro, we could demonstrate that increased concentration of the examined antibiotics in cerebrospinal fluid reduces the amount of MDA. The results obtained demonstrate that products of lipid peroxidation are present in the CSF samples analyzed. In this study, we found that the concentration of vancomycin and netilmicin influenced the lipid peroxidation process in cerebrospinal fluid in children with hydrocephalus, thus confirming anti-inflammatory properties of the antibiotics applied.

Successful treatment of meningoencephalitis caused by methicillin-resistant Staphylococcus aureus with intrathecal vancomycin in an allogeneic peripheral blood stem cell transplant recipient

Methicillin-resistant Staphylococcus aureus (MRSA) is a common infectious pathogen during stem cell trans-plantation. We report a case of meningoencephalitis with multiple abscess formation caused by MRSA, which occurred in a 4-year-old boy soon after allogeneic peripheral blood stem cell transplantation. We successfully cured the infection with a combination of intravenous and intrathecal vancomycin.

Serum procalcitonin in cerebral ventriculitis

OBJECTIVES

The objective of this study was to test the hypothesis that serum procalcitonin is increased in patients with bacterial cerebral ventricular infections after the insertion of temporary external ventricular drains.

PATIENTS AND METHODS

This open, prospective study included patients requiring temporary external ventricular drains for various neurologic conditions such as intracerebral hemorrhage with ventricular hemorrhage or space-occupying lesions in the posterior fossa (cerebellar infarctions or hemorrhages). Patients experiencing primary central nervous system infection or sepsis were excluded. Procalcitonin, C-reactive protein, and white blood cell count were measured daily. Cerebrospinal fluid was investigated every other day, including cerebrospinal fluid cell count, lactate, glucose, and cerebrospinal fluid culture. Results were categorized according to presence of bacterial cerebrospinal fluid infection as determined by positive cerebrospinal fluid cultures.

RESULTS

A total of 34 consecutive patients were included. Procalcitonin was significantly higher (4.7 vs. 0.2 ng/mL) in patients with proven bacterial ventriculitis. Cerebrospinal fluid cell count (456 vs. 478 cells/microL) could not distinguish bacterial infection from abacterial reactions, mainly because of blood contamination of the cerebrospinal fluid.

CONCLUSION

Cerebrospinal fluid of patients treated with temporary external ventricular drains is frequently characterized by blood contamination because of the insertion procedure, the underlying neurologic disorder such as ventricular hemorrhage, or the presence of an abacterial chemical ventriculitis. Thus, diagnosis of a bacterial ventricular infection requiring immediate antibiotic therapy is less certain. Serum procalcitonin adds to the diagnostic precision in bacterial ventriculitis.

Adjunctive rifampin therapy for central nervous system staphylococcal infections

OBJECTIVE

To review the published clinical data assessing the role of adjunctive rifampin therapy for the treatment of staphylococcal central nervous system (CNS) infections.

DATA SOURCES

A MEDLINE search (January 1966-March 2000) of English-language literature pertaining to CNS staphylococcal infections and rifampin was performed; tertiary sources were also used.

DATA EXTRACTION

Human data and case reports were included, as no clinical trials have been published.

DATA SYNTHESIS

Retrospective reviews of rifampin used in combination with other antibiotics for serious bacterial infections show conflicting results. Few case reports have described clinical successes with adjunctive rifampin therapy for CNS infections.

CONCLUSIONS

The routine use of adjunctive rifampin for CNS infections cannot be justified.

Bedside invasive monitoring techniques in severe brain-injured patients

In patients with severe brain injury, brain edema, elevated intracranial pressure, and cerebral ischemia are accountable for a significant morbidity and mortality. New invasive methods of monitoring attempt to foresee the physiopathological mechanisms responsible for the production of secondary brain injuries. The available methods for monitoring severely brain-injured patients, their potential usefulness, advantages, and disadvantages are reviewed.

Bactericidal activity of vancomycin in cerebrospinal fluid

Intraventricular application of vancomycin is an effective therapeutic regimen for the treatment of shunt-associated staphylococcal ventriculitis. We examined the in vitro activity of vancomycin at high concentrations against Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis ATCC 12228 in human cerebrospinal fluid samples. Time-kill curves revealed equal efficacies for concentrations of 10, 100, and 300 microg/ml, and incubation times of 24 to 48 h were needed to achieve a 3 log(10) reduction of viable bacteria. A concentration of 5 microg/ml showed a slightly lower activity, but this difference was not significant. In an infant who was successfully treated for shunt-associated ventriculitis due to S. epidermidis by once-daily local administration of vancomycin (3 mg for 2 days and 5 mg for 4 days [0. 5 to 0.8 mg/kg of body weight]) the in vivo kill kinetics were similar to those for the in vitro results. These results support time-dose regimens that provide trough vancomycin levels of 5 to 10 microg/ml.