The management of cerebrospinal fluid shunt infections: a clinical experience

Cerebrospinal Fluid Shunt Reinfection and Malfunction in Ecuadorian Children with Different Reshunting Criteria After Infection. "Is It Just One Shunt After Another?"

OBJECTIVE

There is no firm evidence regarding cerebrospinal fluid (CSF) shunt reimplantation after infection in the pediatric population. The purpose of this study was to compare different criteria and analyze new shunt failure.

METHODS

A cross-sectional retrospective multicenter study was performed over 6 years to study patients and each infected shunt at diagnosis, reimplantation, and after reimplantation. The patients were divided into 2 groups: group 1 (G1), reimplantation after negative serial CSF cultures during antibiotic treatment; group 2 (G2), reimplantation after negative serial pancultures after completion of antibiotics. The differences were measured with Mann-Whitney and Χ2 tests; multivariate analysis and associations were calculated using odds ratios (ORs) based on logistic regression.

RESULTS

There were 137 shunt infection events in 110 patients: 28 events in G1 and 109 in G2. Significant differences were observed in the diagnosis and reimplantation. Reimplantation dysfunction in G1 was 16 (55.17%) versus 30 (27.78%) in G2 (P = 0.006). The risk of shunt malfunction after reimplantation increased for G1 reimplantation criteria (P = 0.018; OR, 3.34; confidence interval [CI], 1.23-9.05): pleocytosis at diagnosis >17 cells (P = 0.036; OR, 2.41; CI, 1.06-5.47), CSF proteins at diagnosis >182 mg/dL (P = 0.049; OR, 2.21; CI, 1.00-4.89).

CONCLUSIONS

G2 reimplantation criteria were related to improved pleocytosis, CSF proteins, and blood neutrophils compared with G1. Mechanical and infectious dysfunction of the new shunt was 3 times more prevalent in G1 than in G2, considering the differences between the groups at diagnosis. Increased parameters of infection at diagnosis were associated with future malfunction more than parameters before reimplantation in both groups.

Treatment of wound infections linked to neurosurgical implants

As neurosurgery has advanced technologically, more and more neurosurgical implants are being employed on an aging patient population with several comorbidities. As a result, there is a steady increase in the frequency of infections linked to neurosurgical implants, which causes serious morbidity and mortality as well as abnormalities of the skull and inadequate brain protection. We discuss infections linked to internal and external ventricular and lumbar cerebrospinal fluid drainages, neurostimulators, craniotomies, and cranioplasty in this article. Biofilms, which are challenging to remove, are involved in all implant-associated illnesses. It takes a small quantity of microorganisms to create a biofilm on the implant surface. Skin flora bacteria are implicated in the majority of illnesses. Microorganisms that cause disruptions in wound healing make their way to the implant either during or right after surgery. In about two thirds of patients, implant-associated infections manifest early (within the first month after surgery), whereas the remaining infections present later as a result of low-grade infections or by direct extension from adjacent infections (per continuitatem) to the implants due to soft tissue damage. Except for ventriculo-atrial cerebrospinal fluid shunts, neurosurgical implants are rarely infected by the haematogenous route. This research examines established and clinically validated principles that are applicable to a range of surgical specialties using implants to treat biofilm-associated infections in orthopaedic and trauma cases. Nevertheless, there is little evidence and no evaluation in sizable patient populations to support the success of this extrapolation to neurosurgical patients. An optimal microbiological diagnostic, which includes sonicating removed implants and extending culture incubation times, is necessary for a positive result. Additionally, a strategy combining surgical and antibiotic therapy is needed. Surgical procedures involve a suitable debridement along with implant replacement or exchange, contingent on the biofilm's age and the state of the soft tissue. A protracted biofilm-active therapy is a component of antimicrobial treatment, usually lasting 4-12 weeks. This idea is appealing because it allows implants to be changed or kept in place for a single surgical procedure in a subset of patients. This not only enhances quality of life but also lowers morbidity because each additional neurosurgical procedure increases the risk of secondary complications like intracerebral bleeding or ischemia.

Intraventricular Vancomycin Treatment for Shunt-related Ventriculitis Caused by Methicillin-resistant Staphylococcus Aureus in a Preterm Infant: A Case Report

Posthemorragic hydrocephalus is a relatively common condition in prematures, often requiring ventriculoperitoneal shunts. We report a case of methicillin-resistant Staphylococcus aureus infection of a ventriculoperitoneal shunt in a premature neonate which failed conventional intravenous treatment. Despite the absence of published guidelines, we used available data and expert advice to treat the patient with intraventricular vancomycin. The treatment was successful in eradicating the infection without observed toxicity. This case highlights the need for international guidelines on intraventricular treatment for neonates.

Central nervous system infections associated with neurologic devices

PURPOSE OF REVIEW

To review recent data on the epidemiology, microbiology, diagnosis, and management of central nervous system (CNS) infections associated with neurologic devices.

RECENT FINDINGS

The increasing use of implanted neurologic devices has led to an increase in associated infections. Cerebrospinal fluid (CSF) inflammation may be present after a neurosurgical procedure, complicating the diagnosis of CNS infection. Newer biomarkers such as CSF lactate and procalcitonin show promise in differentiating infection from other causes of CSF inflammation. Molecular diagnostic tests including next-generation or metagenomic sequencing may be superior to culture in identifying pathogens causing healthcare-associated ventriculitis and meningitis.

SUMMARY

Neurologic device infections are serious, often life-threatening complications. Rapid recognition and initiation of antibiotics are critical in decreasing morbidity. Device removal is usually required for cure.

Healthcare-associated ventriculitis: current and emerging diagnostic and treatment strategies

Introduction: Healthcare-associated ventriculitis and meningitis occur after neurosurgical procedures, is associated with an adverse outcome in the majority of patients and represent a diagnostic challenge to clinicians. As the cerebrospinal fluid (CSF) culture is the cornerstone of diagnosis, obtaining CSF studies prior to starting antibiotic therapy is key.Areas covered: This review will evaluate the incidence, risk factors, clinical presentation, diagnosis, empirical intravenous antibiotic therapy, adjunctive intrathecal therapy, microbiology, prognosis, and prevention of HCAVM. We highlight the challenges and limitations of the currently available diagnostic methods and definitions and explore novel technologies. Our review included the search for published literature until June 2020.Expert opinion: Despite available preventive measures, HCAVM continues to occur and to be independently associated with significant neurological morbidity and mortality in the majority of patients. The cornerstone of the diagnosis of HCAVM is a positive CSF culture but the microbiological yield is reduced to ~50% with prior antimicrobial therapy. Although the CSF profile is not affected by antibiotic therapy it has a fair diagnostic accuracy. Future research efforts should concentrate in identifying novel diagnostic tools such as polymerase chain reaction (PCR) or metagenomic sequencing.

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 neurosurgical implanted devices

INTRODUCTION

Neurosurgical devices are increasingly used. With it, neurosurgical device-related infections gain relevance. As biofilms are involved in implant-associated infections the diagnosis and treatment is challenging and requires specific anti-biofilm concepts and management algorithms. Areas covered: The literature concerning the management of neurosurgical device-associated infections is scarce and heterogeneous treatment concepts are discussed, but no standardized diagnostic and treatment procedures exist. Therefore, we emphasize extrapolating management strategies predominantly from orthopedic device-associated infections, where the concept is better established and clinically validated. This review covers infections associated with craniotomy fixation devices, cranioplasties, external ventricular and lumbar drainages, internal shunts and neurostimulators. Expert commentary: Sonication of the removed implants significantly improves microbiological diagnosis. A combined surgical and antimicrobial management is crucial for successful treatment: appropriate surgical intervention is combined with prolonged anti-biofilm therapy of usually 12 weeks. In selected patients, new treatment algorithms enable cure of neurosurgical device-associated infections without implant removal or with a one-stage implant exchange, considerably improving the quality of patient lives.

Antibiotic duration and timing of the switch from intravenous to oral route for bacterial infections in children: systematic review and guidelines

Few studies are available to inform duration of intravenous antibiotics for children and when it is safe and appropriate to switch to oral antibiotics. We have systematically reviewed antibiotic duration and timing of intravenous to oral switch for 36 paediatric infectious diseases and developed evidence-graded recommendations on the basis of the review, guidelines, and expert consensus. We searched databases and obtained information from references identified and relevant guidelines. All eligible studies were assessed for quality. 4090 articles were identified and 170 studies were included. Evidence relating antibiotic duration to outcomes in children for some infections was supported by meta-analyses or randomised controlled trials; in other infections data were from retrospective series only. Criteria for intravenous to oral switch commonly included defervescence and clinical improvement with or without improvement in laboratory markers. Evidence suggests that intravenous to oral switch can occur earlier than previously recommended for some infections. We have synthesised recommendations for antibiotic duration and intravenous to oral switch to support clinical decision making and prospective research.

Pediatric hydrocephalus: systematic literature review and evidence-based guidelines. Part 8: Management of cerebrospinal fluid shunt infection

OBJECT

The objective of this systematic review was to answer the following question: What is the optimal treatment strategy for CSF shunt infection in pediatric patients with hydrocephalus?

METHODS

The US National Library of Medicine and the Cochrane Database of Systematic Reviews were queried using MeSH headings and key words relevant to the objective of this systematic review. Abstracts were reviewed, after which studies meeting the inclusion criteria were selected and graded according to their quality of evidence (Classes I-III). Evidentiary tables were constructed that summarized pertinent study results, and based on the quality of the literature, recommendations were made (Levels I-III).

RESULTS

A review and critical appraisal of 27 studies that met the inclusion criteria allowed for a recommendation for supplementation of antibiotic treatment using partial (externalization) or complete shunt hardware removal, with a moderate degree of clinical certainty. However, a recommendation regarding whether complete shunt removal is favored over partial shunt removal (that is, externalization) could not be made owing to severe methodological deficiencies in the existing literature. There is insufficient evidence to recommend the use of intrathecal antibiotic therapy as an adjunct to systemic antibiotic therapy in the management of routine CSF shunt infections. This also holds true for other clinical scenarios such as when an infected CSF shunt cannot be completely removed, when a shunt must be removed and immediately replaced in the face of ongoing CSF infection, or when the setting is ventricular shunt infection caused by specific organisms (for example, gram-negative bacteria).

CONCLUSIONS

Supplementation of antibiotic treatment with partial (externalization) or complete shunt hardware removal are options in the management of CSF shunt infection. There is insufficient evidence to recommend either shunt externalization or complete shunt removal as the preferred surgical strategy for the management of CSF shunt infection. Therefore, clinical judgment is required. In addition, there is insufficient evidence to recommend the combination of intrathecal and systemic antibiotics for patients with CSF shunt infection when the infected shunt hardware cannot be fully removed, when the shunt must be removed and immediately replaced, or when the CSF shunt infection is caused by specific organisms. The potential neurotoxicity of intrathecal antibiotic therapy may limit its routine use.

RECOMMENDATION

Supplementation of antibiotic treatment with partial (externalization) or with complete shunt hardware removal is an option in the management of CSF shunt infection.

STRENGTH OF RECOMMENDATION

Level II, moderate degree of clinical certainty.

RECOMMENDATION

There is insufficient evidence to recommend either shunt externalization or complete shunt removal as a preferred surgical strategy for the management of CSF shunt infection. Therefore, clinical judgment is required.

STRENGTH OF RECOMMENDATION

Level III, unclear degree of clinical certainty.

RECOMMENDATION

There is insufficient evidence to recommend the combination of intrathecal and systemic antibiotics for patients with CSF shunt infection in whom the infected shunt hardware cannot be fully removed or must be removed and immediately replaced, or when the CSF shunt infection is caused by specific organisms. The potential neurotoxicity of intrathecal antibiotic therapy may limit its routine use.

STRENGTH OF RECOMMENDATION

Level III, unclear degree of clinical certainty.

Predictors of in-hospital shunt-dependent hydrocephalus following rupture of cerebral aneurysms

The development of shunt-dependent hydrocephalus is a well-recognised complication after aneurysmal subarachnoid haemorrhage, and negatively impacts on outcomes among survivors. This study aimed to identify early predictors of shunt dependency in a large administrative dataset of aneurysmal subarachnoid haemorrhage patients. We reviewed the National Hospital Morbidity Database in Australia for the years 1998 to 2008 and investigated the incidence of ventricular shunt placement following aneurysmal subarachnoid haemorrhage admissions. Putative risk factors were evaluated with univariate and multivariate logistic regression analysis to identify independent predictors of outcome. The following variables were considered: poor admission neurological grade; aneurysm location; intracerebral haemorrhage; intraventricular haemorrhage; acute hydrocephalus requiring the insertion of an external ventricular drain; surgical clipping; endovascular coiling; meningitis; and prolonged period of external ventricular drainage. A total of 10807 patients hospitalised for aneurysmal subarachnoid haemorrhage were identified. Among them, 701 (6.5%) required a permanent cerebrospinal fluid diversion procedure during the same admission as the aneurysmal subarachnoid haemorrhage. On multivariate analysis, poor admission neurological grade, acute hydrocephalus, the presence of intraventricular haemorrhage, ruptured vertebral artery aneurysm, surgical clipping, endovascular coiling, meningitis, and a prolonged period of external ventricular drainage were significant predictors of shunt dependency. A patient with a ruptured middle cerebral artery aneurysm was unlikely to develop shunt dependency (odds ratio 0.58; 95% confidence interval 0.46-0.73; p < 0.001).

Progression of cerebrospinal fluid cell count and differential over a treatment course of shunt infection

OBJECT

The physiological reaction of CSF white blood cells (WBCs) over the course of treating a shunt infection is undefined. The authors speculated that the CSF WBC count varies with different infecting organisms in peak level and differential percentage of polymorphonuclear (PMN) leukocytes, lymphocytes, monocytes, and eosinophils. The authors hope to identify clinically useful trends in the progression of CSF WBCs by analyzing a large group of patients with successfully treated shunt infections.

METHODS

The authors reviewed 105 successfully treated cases of shunt infections at Riley Hospital for Children. The study dates ranged from 2000 to 2004; this represented a period prior to the routine use of antibiotic-impregnated shunt catheters. They analyzed the following organisms: coagulase-negative staphylococci, Staphylococcus aureus, Propionibacterium acnes, Streptococcal species, and gram-negative organisms. The initial CSF sample at diagnosis was analyzed, as were levels over 14 days of treatment. Model fitting was performed to generate curves for the expected progression of the WBC counts and the differential PMN leukocytes, lymphocyte, monocyte, and eosinophil percentages.

RESULTS

Gram-negative organisms resulted in a higher initial (p = 0.03) and peak WBC count with a greater differential of PMN leukocytes compared with other organisms. Propionibacterium acnes infections were associated with a significantly lower WBC count and PMN leukocytes percentage (p = 0.02) and higher eosinophil percentage (p = 0.002) than other organisms. The pattern progression of the CSF WBC count and differential percentages was consistent for all infections. There was an initial predominance of PMN leukocytes, followed by a delayed peak of lymphocytes, monocytes, and eosinophils over a 14-day course. All values trended toward zero over the treatment course.

CONCLUSIONS

The initial and peak levels of CSF WBCs vary with the infecting organisms. The CSF cell counts showed a predictable pattern during the treatment of shunt infection. These trends may be useful to the physician in clinical decision making, although there is a wide range of variability.

Hydrocephalus Indian scenario - A review

Hydrocephalus is a common clinical problem seen in pediatric neurosurgical practice. Hydrocephalus involves dilatation of the cerebral ventricular system with corresponding, compressive effects on the parenchyma. It can be communicative or obstructive types. Congenital, acquired, infective, and secondary hydrocephalus have different clinical features with different modality of treatments. Ventriculoperitoneal shunt is the gold standard of treatment. Endoscopic 3(rd) ventriculostomy is rapidly gaining prominence as an alternative. Various kinds of hydrocephalus, their pathophysiology, treatment and complications are reviewed.

Linezolid treatment of shunt-related cerebrospinal fluid infections in children

OBJECT

The emergence of multidrug-resistant bacteria as a cause of ventriculoperitoneal (VP) shunt infection is a disconcerting phenomenon that often requires the use of alternative antimicrobial agents due to resistance against commonly used medications. Linezolid, a member of a new class of antimicrobial agents, has good activity against virtually all important gram-positive pathogens, including multidrug-resistant gram-positive pathogens. The object of this article is to report a single-center experience with linezolid treatment in 6 young patients with VP shunt infections caused by drug-resistant strains.

METHODS

The authors reviewed the records of 6 pediatric patients who developed VP shunt infection and in whom initial antimicrobial treatment regimens, including vancomycin, either failed or were associated with vancomycin-resistant enterococcus. All 6 patients were treated at their hospital between July 1, 2008, and June 29, 2009. The patients' demographic and clinical characteristics, underlying diseases, clinical manifestations, laboratory results, and various treatment modalities used before linezolid therapy were evaluated.

RESULTS

The 6 patients included were 2 boys and 4 girls with a mean (+/- SD) age of 11.83 +/- 12 months (range 4-36 months). Five patients had acquired an infection within 4 months (mean 7.50 +/- 13.51 months, range 1-35 months) after shunt insertion. Four patients were treated with external ventricular drainage. Two patients' parents refused to allow shunt removal and placement of an external ventricular drain. The CSF was clear of bacterial growth within a mean of 3.67 +/- 1.36 days (range 2-6 days) after initiation of linezolid treatment. The mean duration of linezolid treatment was 18.17 +/- 3.31 days (range 14-21 days). Microbiological clearance of CSF and clinical cure were achieved in all patients. No laboratory or clinical side effects were observed during the treatment period. The mean length of hospital stay was 22.8 +/- 4.96 days (range 17-28 days).

CONCLUSIONS

Linezolid could be an appropriate treatment alternative in children with ventriculostomy-related CSF infections caused by drug-resistant strains, including cases in which shunt removal is not an option. Well-designed prospective studies providing additional information on linezolid levels in plasma and CSF are necessary to confirm the authors' observations.

Predisposing factors related to shunt-dependent chronic hydrocephalus after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Hydrocephalus is a common sequelae of aneurysmal subarachnoid hemorrhage (SAH) and patients who develop hydrocephalus after SAH typically have a worse prognosis than those who do not. This study was designed to identify factors predictive of shunt-dependent chronic hydrocephalus among patients with aneurysmal SAH, and patients who require permanent cerebrospinal fluid diversion.

METHODS

Seven-hundred-and-thirty-four patients with aneurysmal SAH who were treated surgically between 1990 and 2006 were retrospectively studied. Three stages of hydrocephalus have been categorized in this paper, i.e., acute (0-3 days after SAH), subacute (4-13 days after SAH), chronic (>/=14 days after SAH). Criteria indicating the occurrence of hydrocephalus were the presence of significantly enlarged temporal horns or ratio of frontal horn to maximal biparietal diameter more than 30% in computerized tomography.

RESULTS

Overall, 66 of the 734 patients (8.9%) underwent shunting procedures for the treatment of chronic hydrocephalus. Statistically significant associations among the following factors and shunt-dependent chronic hydrocephalus were observed. (1) Increased age (p < 0.05), (2) poor Hunt and Hess grade at admission (p < 0.05), (3) intraventricular hemorrhage (p < 0.05), (4) Fisher grade III, IV at admission (p < 0.05), (5) radiological hydrocephalus at admission (p < 0.05), and (6) post surgery meningitis (p < 0.05) did affect development of chronic hydrocephalus. However the presence of intracerebral hemorrhage, multiple aneurysms, vasospasm, and gender did not influence on the development of shunt-dependent chronic hydrocephalus. In addition, the location of the ruptured aneurysms in posterior cerebral circulation did not correlate with the development of shunt-dependent chronic hydrocephalus.

CONCLUSION

Hydrocephalus after aneurysmal SAH seems to have a multifactorial etiology. Understanding predisposing factors related to the shunt-dependent chronic hydrocephalus may help to guide neurosurgeons for better treatment outcomes.

Management of complicated shunt infections: a clinical report

OBJECTIVES

The authors present their experience with a protocol for the treatment of patients with complicated shunt infections.

METHODS

Complicated shunt infections are defined for the purpose of this protocol as multiple compartment hydrocephalus, multiple organism shunt infection, severe peritonitis, or infections in other sites of the body. The initial treatment protocol for these patients was 3 weeks of intravenous antibiotic therapy and 2 weeks of twice daily intraventricular/intrashunt antibiotic therapy. Cerebrospinal fluid (CSF) cultures were monitored during therapy and obtained again 48 hours after completion. The shunt was completely replaced. Additionally, follow-up cultures were obtained in all patients 3-6 months after therapy was completed.

RESULTS

A cure of the infection was achieved in all patients as defined by negative cultures obtained at completion of antibiotic therapy and in follow-up studies. The follow-up period was 2-11 years (mean 4.4 +/- 2.5 years). The treatment protocol was modified in the patients treated after 1991, and 18 patients were treated with this modified treatment regime. In these patients, intraventricular antibiotics were administered only once daily for 14 days, and the CSF was cultured 24 hours after antibiotic therapy had been stopped instead of after 48 hours. The results were similar to those obtained with the initial protocol.

CONCLUSIONS

Based on their prospective nonrandomized series, the authors believe that patients with complicated shunt infections can be successfully treated with 2 weeks of intraventricular antibiotic therapy administered once daily, concurrent with 3 weeks of intravenous antibiotic therapy. This protocol reduces length of treatment and hospital stay, and avoids recurrence of infection.

Aggressive management of shunt infection: combined intravenous and intraventricular antibiotic therapy for twelve or less days

OBJECTIVE

This report is limited to patients with a single cerebrospinal fluid (CSF) shunt infected by a single organism, and compares two treatment protocols.

METHODS

In the initial protocol (1975-1991), patients underwent removal of the shunt system and received intravenous and intraventricular antibiotics. Intraventricular antibiotics were administered twice daily to those with external ventricular drainage. When CSF was cultured 48 h off all antibiotics and found to be sterile at 24 h of incubation, a new shunt was inserted. Follow-up CSF cultures were obtained in all patients between 1-6 months following placement of the new shunt.

RESULTS

There were 25 patients (ages 1 month to 16 years; mean +/- SD: 23 +/- 4.0 months). CSF obtained from the shunt yielded the following: Staphylococcus epidermidis (19), Staphylococcus aureus (2), Streptococcus species (2), Serratia marcescens (1), and Propionebacterium species (1). The duration of intravenous antibiotics was 7-12 days (mean +/- SD: 9.7 +/- 1.3 days), and intraventricular antibiotic therapy was 6.2 +/- 1.7 days. Total hospital stay was 15.2 +/- 2.3 days. The follow-up period was 7.7 +/- 3.6 years. Following the initial protocol in another 15 patients (1992-2004), the treatment regime was modified in that intraventricular antibiotics were administered once daily in patients with external ventricular drainage, and the CSF was cultured at 24 h off antibiotics, instead of 48 h. Results were similar to the initial protocol with respect to days of antibiotic therapy and hospital stay.

CONCLUSION

Based on our retrospective nonrandomized series, we believe patients with a single shunt and noncompartmentalized hydrocephalus can be successfully treated without a prolonged antibiotic course and lengthy hospital stay.

Linezolid treatment of ventriculoperitoneal shunt infection without implant removal

Ventriculoperitoneal shunt infection is a serious clinical problem for which implant removal is considered the treatment of choice. However, surgery is sometimes associated with considerable risks that may outweigh the benefits. Presented here is a case of ventriculoperitoneal shunt infection treated successfully with linezolid without implant removal. This case shows linezolid could be a therapeutic alternative when surgery is contraindicated.

Cerebrospinal fluid shunt infection secondary to Escherichia coli bacteriuria

A 10-year-old girl with a lumbosacral myelomeningocele, managed with clean intermittent catheterization, presented with headache, vomiting, and lethargy. The cerebrospinal fluid (CSF) and urine cultures revealed Escherichia coli, documented to be the same subtype. The organisms were subtyped and the E. coli from both the urine and CSF were noted to be of the same strain. Management consisted of intravenous antibiotics and ultimate replacement of the ventriculoperitoneal shunt. Children with myelodysplasia and CSF shunts should be carefully monitored in a multidisciplinary fashion to anticipate, correctly diagnose, and treat CSF shunt infections associated with bacteriuria.

CSF shunt infections in children

The incidence of shunt infections and possible risk factors was investigated by chart analysis. From 1986 to 1989 350 shunt procedures were performed including 273 ventriculoperitoneal shunts and 75 ventriculoatrial shunts. Twenty-eight infectious episodes (8%) occurred in 25 patients during a median follow-up time of 20 months. For 204 patients the follow-up time could be prolonged until September 1992. In these patients no infectious episodes occurred in the extended observation period. In 24 cases (85.7%) a causative organism could be isolated. The infecting organisms were gram-positive cocci in 22 cases (78.6%) and gram-negative bacilli in two cases. The main signs and symptoms were fever, shunt malfunction and meningeal irritation, and with VP-shunts only, abdominal pain. Twenty-four infectious episodes were treated with antibiotics and immediate removal of the shunt. The remaining were managed with antibiotics only. The risk for shunt infection did not correlate with age or sex of patients, nor with the etiology of hydrocephalus, type of shunt implanted or perioperative antibiotic prophylaxis. However, a trend showing a higher risk for shunt infections with prolonged operation time was noticed. The infection rate was 13.6% for an operation lasting more than 90 minutes versus 5.2% for procedures of less than 30 minutes duration.

Populations at risk for penicillin-induced seizures

OBJECTIVE

This article reviews principles associated with penicillin's epileptogenic activity in an effort to alert clinicians of patients at high risk for penicillin-induced seizures. The case presentation exemplifies the most prevalent factor predisposing patients to penicillin-induced seizures--renal impairment.

DATA SOURCES

References are identified from pertinent articles and books.

DATA SYNTHESIS

The epileptogenic properties of penicillin are explained on the basis of the beta-lactam ring's binding to gamma aminobutyric acid receptors. Several patient populations are at risk for potentially fatal neurotoxic symptoms. Most of these patients demonstrate impaired renal function, either as the primary condition or secondary to an infectious process. The other at-risk populations include infants and the elderly, patients with meningitis, patients undergoing intraventricular antibiotic therapy, and patients with a history of seizures. Treatment remains controversial; however, benzodiazepines theoretically produce a favorable response.

CONCLUSIONS

Pharmacokinetic parameters explain patient populations most at risk; a guideline equation has been recommended to allow clinicians to make appropriate dose adjustments based on creatinine clearance. Physicians and pharmacists must recognize the populations most at risk for high-dose, penicillin-induced neurotoxicities; monitor these patients at least during the first 72 hours, and reduce or discontinue therapy when appropriate.

Intraventricular nafcillin-induced seizures in a neonate

Treatment of cerebrospinal fluid shunt infections commonly involves a combination of intravenous and intraventricular antibiotics. We report a premature infant who developed seizures associated with intraventricular administration of nafcillin and discuss the need for electroencephalographic monitoring of patients receiving intraventricular antibiotics.

Management of infectious complications of intraventricular reservoirs in cancer patients: low incidence and successful treatment without reservoir removal

At the time of analysis, the first 30 patients with Ommaya reservoirs (OR) at the Children's Orthopedic Hospital and Medical Center in Seattle, Washington had had 32 reservoirs for a mean duration of 28 months. In all, the reservoir chambers had been punctured for either diagnostic or therapeutic purposes a total of 1,287 times with a mean of 40 injections per reservoir and 1.4 injections per month. Six reservoir infections were diagnosed in five patients--a rate of one infection for every 153 reservoir-months. Four infections were attributed to reservoir use--a rate of one infection for every 322 reservoir entries, and less than one infection in 900 entries when a standard aseptic protocol for sampling and injection was applied. There was no correlation between infectious complications and the frequency with which reservoirs were injected, but there was evidence that some of the infections resulted from incomplete compliance with recommended technique for skin preparation and reservoir entry. Four infections were treated successfully with intravenous and intra-reservoir antibiotics without reservoir removal. Only one reservoir had to be removed because of persistent infection. Two other reservoirs were removed because of trauma and malfunction. Twenty-seven patients (90%) retained their original reservoir, up to 9.5 years after implantation. Intraventricular chemotherapy via an indwelling subcutaneous reservoir is a preferred method for delivery of intrathecal chemotherapy, with an acceptable infection risk relative to the benefits of patient comfort and therapeutic efficacy.

An analysis of cerebrospinal fluid shunt infections in adults. A clinical experience of twelve years

The authors analyze a group of 451 shunt operations where 317 patients had hydrocephalus and 23 cases were reported positive after cerebrospinal fluid (CSF) cultures. Staphylococcus was the most frequent bacterial organism found (57%). This retrospective study of 23 patients in whom infection developed following placement of an extrathecal shunt, although not a complete biometric evaluation, shows an incidence of infection of 5%. The authors also indicate the limitations in antibiotic treatment when three significant aspects of therapy are not considered fully: 1. sensitivity of the identified organism, 2. CSF levels of the drug that can be attained, and 3. the pharmacokinetic action of the drug in the CSF.

Infections in neurosurgery: a retrospective study of 1143 patients and 1517 operations

The files of 1143 neurosurgical patients, operated on between November 1, 1979 and June 4, 1981 were examined for records of post-operative infections. Eighty-three patients had developed infections (7%). In addition there were 33 instances of aseptic meningitis. Patients with a shunt were prone to infection (12%). Bone flap infections accounted for more than half of all infections after supratentorial craniotomy. Bacterial meningitis accounted for more than half of all infections after suboccipital craniotomy and translabyrinthine operations. In these patients bacterial meningitis was six times more common, and aseptic meningitis three times more common than in those who had had supratentorial operations. Shunt infection was more common after repeated shunt operations in quick succession. Craniotomy increased the risk of a shunt becoming infected. Antibiotic prophylaxis should be used not only in shunt operations but in all operations performed on patients with a shunt. If bacteria are recovered in a suspected shunt infection, immediate removal of the shunt is the best treatment. However, if the shunt's removal or replacement is exceptionally difficult intraventricular antibiotic treatment may be tried. The age of the patient, the duration of the operation, the individual surgeon and the number of operations did not affect the rate of infection. Clinical signs and conventional laboratory tests, apart from bacterial culture, cannot differentiate between bacterial and aseptic meningitis, but a drop in the level of consciousness suggests bacterial meningitis.

Shunt fluid examination: risks and benefits in the evaluation of shunt malfunction and infection

A combined retrospective and prospective study was designed to assess the efficacy of shunt fluid examination in the evaluation of shunt malfunction and/or infection, and to ascertain the complication rate associated with this procedure. Ninety-one patients with shunts for the treatment of hydrocephalus underwent a total of 209 diagnostic shunt "taps." Of 72 instances of mechanical obstruction documented at surgery, 70 were correctly identified by abnormal shunt fluid dynamics, either an opening cerebrospinal fluid (CSF) pressure in excess of the expected valve pressure or absent flow of fluid. The organisms responsible for 12 of 13 shunt-related infections were correctly isolated on initial and all subsequent shunt fluid cultures obtained prior to the institution of appropriate antibiotics. With one infection, a bacterial pathogen was not identified until the third tap. In all instances in which lumbar or ventricular CSF, blood, or wound cultures disclosed an organism, shunt fluid cultures also identified the agent. In addition, these procedures were less reliable. No complications occurred during or immediately following any of the shunt taps. Long-term consequences were assessed in 53 patients with an average follow-up period of 26 months. Some shunt systems subsequently required revision and two infections were documented. The uniformly long interval between the shunt fluid examination and these complications makes it unlikely that the taps contributed to the development of malfunction or infection. Shunt fluid examination appears to be a simple, benign, and yet accurate means of diagnosing shunt malfunction and/or shunt-related infection.