Ventriculoperitoneal shunt infections with gram-negative bacteria

Global trends in the evaluation and management of cerebrospinal fluid shunt infection: a cooperative ISPN survey

INTRODUCTION

Ventriculoperitoneal shunts (VPS) is commonly performed by pediatric neurosurgeons and there is no consensus in management of VPS infection as it relates to diagnosis and treatment.

OBJECTIVE

We utilized an international practitioner-based survey to study the variability in VPS infection diagnostic and therapeutic measures.

METHODS

A survey gauging practice patterns of pediatric neurosurgeons regarding VPS and its complication management was distributed. Survey endpoints were analyzed by VPS case volume and pediatric-focused case volume regarding diagnostic measures, use of cerebrospinal fluid (CSF) profile, microbiology, and treatment.

RESULTS

A total of 439 surveys were distributed, with a response rate of 31%. Responders ranged from Americas (44.9%), European (31.4%), Asian (18.6%), African (2.5%), to Australian continents (2.5%). Practitioners were stratified based on number and percentage pediatric VPS performed. Institutions performing highest VPS and percentage pediatric case volumes had lower rate of VPS infection. Shunt tap was the most widely used diagnostic study. Overall CSF profile did not affect decision making towards VPS internalization, except for leukocyte count ≤ 20 × 10⁹/L. Practitioners utilized 3 negative cultures prior to VPS internalization. Discrepancies in surgical management were noted amongst centers with high versus low VPS volume and proportion of pediatric-focused case volume. Practice patterns were not noted to be organism dependent. Antibiotic-impregnated shunts were utilized in the Americas and Europe over other regions but only in one third of all initial VPS or as a preventive strategy after a VPS infection has been resolved respectively.

DISCUSSION

Survey results from 6 continents in VPS management revealed patterns of lower infection in high-volume centers, 3 negative cultures prior to internalization and aggressive surgical VPS infection management in high-volume institutions.

Role of Biofilm in Cerebrospinal Fluid Shunt Infections: A Study at Tertiary Neurocare Center from South India

INTRODUCTION

Biofilms are the source of persistent infections of many pathogenic microbes. They are responsible for nosocomial infection and also associated with many surgical conditions including indwelling medical devices such as ventriculoperitoneal shunt. A significant problem encountered in shunt procedures is obstruction followed by infection, with infection rate ranging from 2% to 27%, often with poor outcome.

MATERIALS AND METHODS

This study was conducted in the Department of Neuromicrobiology at a tertiary neuroinstitute for 6 months from July 1 to December 31, 2014. The samples comprised cerebrospinal fluid (CSF) from suspected cases of shunt infections. Laboratory diagnosis of causative agent was established by adopting standard procedures. Then, isolates were evaluated for production of biofilm by tissue culture plate (TCP) method and tube method.

RESULTS

Of the 1642 shunt CSF samples obtained from neurosurgery, 14.79% were culture positive which yielded 254 isolates. About 51.97% were Gram-negative bacilli (GNB), 46.46% were Gram-positive cocci (GPC), and 1.57% were Candida albicans. Among GNB, nonfermenters were the most common (51.52%) followed by Pseudomonas aeruginosa (15.9%). Among GPC, coagulase-negative Staphylococci were 88.13%, out of which 43.26% were methicillin-resistant. Other GPC were Enterococcus spp. (4.24%), Staphylococcus aureus (5.08%), and Streptococcus spp. (2.54%). Among all isolates, 120 were tested for biofilm production, out of which 57.5% were biofilm producers and 42.5% were nonproducers.

CONCLUSIONS

TCP was the better method to detect biofilm. Most of the biofilm producers were resistant pathogens.

Evaluation of an in vivo model for ventricular shunt infection: a pilot study using a novel antimicrobial-loaded polymer

OBJECTIVE

Ventricular shunt infection remains an issue leading to high patient morbidity and cost, warranting further investigation. The authors sought to create an animal model of shunt infection that could be used to evaluate possible catheter modifications and innovations.

METHODS

Three dogs underwent bilateral ventricular catheter implantation and inoculation with methicillin-sensitive Staphylococcus aureus (S. aureus). In 2 experimental animals, the catheters were modified with a polymer containing chemical "pockets" loaded with vancomycin. In 1 control animal, the catheters were polymer coated but without antibiotics. Animals were monitored for 9 to 11 days, after which the shunts were explanted. MRI was performed after shunt implantation and prior to catheter harvest. The catheters were sonicated prior to microbiological culture and also evaluated by electron microscopy. The animals' brains were evaluated for histopathology.

RESULTS

All animals underwent successful catheter implantation. The animals developed superficial wound infections, but no neurological deficits. Imaging demonstrated ventriculitis and cerebral edema. Harvested catheters from the control animal demonstrated > 104 colony-forming units (CFUs) of S. aureus. In the first experimental animal, one shunt demonstrated > 104 CFUs of S. aureus, but the other demonstrated no growth. In the second experimental animal, one catheter demonstrated no growth, and the other grew trace S. aureus. Brain histopathology revealed acute inflammation and ventriculitis in all animals, which was more severe in the control.

CONCLUSIONS

The authors evaluated an animal model of ventricular shunting and reliably induced features of shunt infection that could be microbiologically quantified. With this model, investigation of pathophysiological and imaging correlates of infection and potentially beneficial shunt catheter modifications is possible.

Relationship of causative organism and time to infection among children with cerebrospinal fluid shunt infection

OBJECTIVE

Infection is a common complication of cerebrospinal fluid (CSF) shunts, occurring in 6%-20% of children. Although studies are limited, Staphylococcus aureus is thought to cause more rapid and aggressive infection than coagulase-negative Staphylococcus (CONS) or gram-negative organisms. The authors' objective was to evaluate the relationship between the causative organisms of CSF shunt infection and the timing of infection.

METHODS

The authors performed a retrospective cohort study of children who underwent CSF shunt placement at a tertiary care children's hospital over a 9-year period and subsequently developed a CSF shunt infection. The primary predictor variable was the causative organism recovered from CSF culture, characterized as S. aureus, CONS, or gram-negative organisms. The primary outcome was time to infection, defined as the number of days from most recent shunt intervention to the diagnosis of the infection. The association between causative organism and time to infection was visualized using Kaplan-Meier curves, and statistical comparisons were made using nonparametric Kruskal-Wallis tests.

RESULTS

Among 103 children in whom a CSF shunt infection developed, the causative organism was CONS in 57 (55%), S. aureus in 19 (18%), and gram-negative organisms in 9 (9%). The median time to infection did not differ (p = 0.81) for infections caused by CONS (20 days, IQR 11-40), S. aureus (26 days, IQR 12-95), and gram-negative organisms (23 days, IQR 17-34).

CONCLUSIONS

No significant difference in time to infection based on the causative organism was observed among children with a CSF shunt infection.

Bacteria causing ventriculoperitoneal shunt infections in a Kenyan population

OBJECT

Ventriculoperitoneal shunt (VPS) infections are a major cause of morbidity and mortality in patients with hydrocephalus. Most data about these infections come from the Western literature. Few data about infecting organisms in Africa are available, yet knowledge of these organisms is important for the prevention and treatment of infectious complications. The purpose of this study was to determine the organisms cultured from infected shunts in a rural Kenyan hospital.

METHODS

The authors conducted a retrospective study of patients with VPS infections recorded in the neurosurgical database of BethanyKids at Kijabe Hospital between September 2010 and July 2012.

RESULTS

Among 53 VPS infections confirmed by culture, 68% occurred in patients who were younger than 6 months. Seventy-nine percent of the infections occurred within 2 months after shunt insertion. Only 51% of infections were caused by Staphylococcus species (Staphylococcus aureus 25%, other Staphylococcus species 26%), whereas 40% were caused by gram-negative bacteria. All S. aureus infections and 79% of other Staphylococcus infections were sensitive to cefazolin, but only 1 of 21 gram-negative bacteria was sensitive to it. The majority of gram-negative bacterial infections were multidrug resistant, but 17 of the 20 gram-negative bacteria were sensitive to meropenem. Gram-negative bacterial infections were associated with worse outcomes.

CONCLUSIONS

The high proportion of gram-negative infections differs from data in the Western literature, in which Staphylococcus epidermidis is by far the most common organism. Once a patient is diagnosed with a VPS infection in Kenya, immediate treatment is recommended to cover both gram-positive and gram-negative bacterial infections. Data from other Sub-Saharan countries are needed to determine if those countries have the same increased frequency of gram-negative infections.

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.

Paediatric ventriculoperitoneal shunt infection caused by Actinomyces neuii

We present the first reported case of ventriculoperitoneal shunt infection secondary to Actinomyces neuii in a paediatric patient. Our patient was managed with temporary shunt removal, intrathecal antibiotics and a prolonged course of intravenous and then oral antibiotics. She went on to make a complete recovery. Subsequent cerebrospinal fluid analysis at 5 months post-treatment demonstrated no evidence of residual infection.

Antimicrobial treatment options for neurosurgical ventricular shunt infections in children from 1993 to 2012: a systematic review

PURPOSE

The aim of this systematic review was to review studies that existed from 1993 to 2012 regarding antimicrobial treatment options of paediatric neurosurgical shunt.

METHODS

Studies were identified from MEDLINE, Scopus and Cochrane databases using a search strategy that was registered on the PROSPERO database. Studies were included if they had two or more patients, aged less than 18 years, and also specified the organism and antimicrobial treatment that was used.

RESULTS

The search yielded 2,985 articles, and 76 articles were suitable for full review. In the final qualitative analysis, only eight studies were included, involving 86 participants. The most common antimicrobial regimens for Gram-positive infections was intravenous and intrathecal vancomycin (n = 7), followed by intravenous vancomycin monotherapy.

CONCLUSION

This systematic review has shown that there are no prospective randomised studies of antimicrobial treatment options for paediatric neurosurgical patients in the last 20 years, and larger prospective studies are urgently required for this serious infection. There is some limited case series showing the benefits of certain antimicrobials such as vancomycin and ceftriaxone, but a larger case series or randomised controlled trial is required, particularly to establish the benefit, if any, of additional intraventricular antimicrobials.

Ventriculoperitoneal shunt infection with non-typhoidal Salmonella species in an infant

Shunt infections are common in pediatric neurosurgery. We present a case of a 3-month-old male with a history of a ventriculoperitoneal shunt for posthemorrhagic hydrocephalus after premature birth who presented to the emergency department with irritability and decreased oral intake. His presentation was concerning for shunt infection and evaluation for this was undertaken. He was found to have a shunt infection due to non-Salmonellatyphi species, a rare cause of meningitis in children in the United States and rarer cause of shunt infection. With effective treatment for this organism, the patient did well and was discharged home in good condition.

Incidence and risk factors of ventriculoperitoneal shunt infections in children: a study of 333 consecutive shunts in 6 years

The major aims of this study were to estimate the infection rate and recognize the risk factor for ventriculoperitoneal (VP) shunt infections in children. To analyze shunt infection rate and identify risk factors, a retrospective cohort analysis of 333 consecutive VP shunt series was performed at Seoul National University Children's Hospital in Korea between January 2005 and February 2011. Overall, 35 shunts (10.5%) were infected, which represented an infection rate of 0.075 infection cases per shunt per year. VP shunt infection occurred at a median of 1 month (range, 6 days to 8 months) after insertion. An independent risk factor for shunt infection was undergoing an operation before the first year of life (relative risk 2.31; 95% confidence interval, 1.19-4.48). The most common causative microorganism was coagulase-negative staphylococci in 16 (45.7%) followed by Staphylococcus aureus in 8 (22.9%). Methicillin resistance rate was 83.3% among coagulase-negative staphylococci and S. aureus. In this study, cerebrospinal fluid shunt infection rate was 10.5%. Infection was frequently caused by methicillin-resistant coagulase-negative staphylococci and S. aureus within two months after shunt surgery. Vancomycin may be considered as the preoperative prophylaxis for shunt surgery in a situation where methicillin resistance rate is very high.

Intraventricular antibiotics for bacterial meningitis in neonates

BACKGROUND

Neonatal meningitis may be caused by bacteria, especially gram-negative bacteria, which are difficult to eradicate from the cerebrospinal fluid (CSF) using safe doses of antibiotics. In theory, intraventricular administration of antibiotics would produce higher antibiotic concentrations in the CSF than intravenous administration alone, and eliminate the bacteria more quickly. However, ventricular taps may cause harm.

OBJECTIVES

To assess the effectiveness and safety of intraventricular antibiotics (with or without intravenous antibiotics) in neonates with meningitis (with or without ventriculitis) as compared to treatment with intravenous antibiotics alone.

SEARCH METHODS

The Cochrane Library, Issue 2, 2007; MEDLINE; EMBASE; CINAHL and Science Citation Index were searched in June 2007. The Oxford Database of Perinatal Trials was searched in June 2004. Pediatric Research (abstracts of proceedings) were searched (1990 to April 2007) as were reference lists of identified trials and personal files. No language restrictions were applied.This search was updated in May 2011.

SELECTION CRITERIA

Selection criteria for study inclusion were: randomised or quasi-randomised controlled trials in which intraventricular antibiotics with or without intravenous antibiotics were compared with intravenous antibiotics alone in neonates (< 28 days old) with meningitis. One of the following outcomes was required to be reported: mortality during initial hospitalisation; neonatal or infant mortality, or both; neurodevelopmental outcome; duration of hospitalisation; duration of culture positivity of CSF and side effects.

DATA COLLECTION AND ANALYSIS

All review authors abstracted information for outcomes reported and one review author checked for discrepancies and entered data into RevMan 5.1. Risk ratio (RR), risk difference (RD), number needed to treat for an additional beneficial outcome (NNTB) or number needed to treat for an additional harmful outcome (NNTH), and mean difference (MD), using the fixed-effect model are reported with 95% confidence intervals (CI).

MAIN RESULTS

The updated search in June 2011 did not identify any new trials. One study is included in the review. This study assessed the effect of intraventricular gentamicin in a mixed population of neonates (69%) and older infants (31%) with gram-negative meningitis and ventriculitis. Mortality was statistically significantly higher in the group that received intraventricular gentamicin in addition to intravenous antibiotics compared to the group receiving intravenous antibiotics alone (RR 3.43; 95% CI 1.09 to 10.74; RD 0.30; 95% CI 0.08 to 0.53); NNTH 3; 95% CI 2 to 13). Duration of CSF culture positivity did not differ significantly (MD -1.20 days; 95% CI -2.67 to 0.27).

AUTHORS' CONCLUSIONS

In one trial that enrolled infants with gram-negative meningitis and ventriculitis, the use of intraventricular antibiotics in addition to intravenous antibiotics resulted in a three-fold increased RR for mortality compared to standard treatment with intravenous antibiotics alone. Based on this result, intraventricular antibiotics as tested in this trial should be avoided. Further trials comparing these interventions are not justified in this population.

A simple method to reduce infection of ventriculoperitoneal shunts

OBJECT

Postoperative shunt infection is the most common and feared complication of ventriculoperitoneal (VP) shunt placement for treatment of hydrocephalus. The rate of shunt infection is highest in the 1st postoperative month. The most common organisms responsible for shunt infection include coagulase-negative Staphylococcus and Staphylococcus aureus. This suggests a transfer of patient's skin flora via the surgeons' glove as a possible means of infection. The authors conducted a study to determine if the rate of postoperative shunt infections could be reduced simply by changing gloves before handling the shunt catheter.

METHODS

A total of 111 neonates born with congenital hydrocephalus requiring a VP shunt were enrolled retrospectively and divided into 2 groups: a control group of 54 neonates treated with standard protocol VP shunt placement (Group A) and a treatment group of 57 neonates in whom, after initially double gloving, the outer pair of gloves was removed before handling the shunt catheter (Group B). Shunt infection rates were compared up to 6 months postoperatively.

RESULTS

There was a statistically significant reduction of infection rate from 16.33% in Group A (control) to 3.77% in Group B (p = 0.0458).

CONCLUSIONS

The study shows that a changing of gloves before handling the shunt catheter may be a simple and cost-effective way to reduce the burden of postoperative shunt infections.

How long should cerebrospinal fluid cultures be held to detect shunt infections? Clinical article

OBJECT

Infections of CSF hardware may be indolent, and some patients have received antibiotic treatment for various reasons before CSF is obtained to check for a shunt infection. At present, there are few data in the literature to guide the decision as to how long to hold CSF specimens when attempting to diagnose hardware infections, and institutions vary in the duration at which cultures are considered "final."

METHODS

The authors reviewed the microbiology data from CSF specimens obtained from shunts, ventriculostomies, reservoirs, and lumbar drains at their institution over a 36-month period to discover how long after collection cultures became positive. The authors also sought to discover whether this time was affected by prior treatment with antibiotics.

RESULTS

Of 158 positive CSF specimens obtained from hardware, the time to recovery ranged between 1-10 days, with a mean of 3.02 days (SD 2.37 days, 95% CI 2.66-3.38 days). One hundred and twenty-seven positive specimens were associated with clinical infections, and approximately 25% of these grew organisms after > 3 days, with some as long as 10 days after specimens were obtained. The most common organisms grown from individual patients were coagulase-negative Staphylococcus spp (34 cultures), Propionibacterium spp (21), Bacillus spp (6), Pseudomonas aeruginosa (4), and Staphylococcus aureus (4 cultures). Mean and maximum days to recovery were different across species, with S. aureus showing the shortest and Propionibacterium spp showing the longest incubation times. There appeared to be no significant difference in the time to recovery between specimens obtained in patients who had received prior antibiotic treatment versus those who had not.

CONCLUSIONS

A substantial number of positive CSF specimens obtained in patients with clinical infections grew bacteria after > 3 days, with some requiring as long as 10 days. Thus, a routine 10-day observation period for CSF specimens can be justified.

Cerebrospinal fluid shunt infections in children over a 13-year period: anaerobic cultures and comparison of clinical signs of infection with Propionibacterium acnes and with other bacteria

OBJECT

Shunt infections represent a major problem with risk for sequelae and even death. The aim in this retrospective study was to analyze the incidence, origin, and clinical presentation of shunt infections, with special reference to the results of cultures for anaerobic organisms performed in addition to the usual tests, to prolonged incubation times, and to infections caused by Propionibacterium acnes.

METHODS

The medical records of 237 hydrocephalic children (age range 0-15 years) in whom operations were performed by a pediatric surgeon at Uppsala University Hospital during a 13-year period were reviewed.

RESULTS

Thirty-four verified or suspected intraventricular shunt infections and 5 distal catheter infections occurred after 474 operations. Skin bacteria, such as coagulase-negative staphylococci ([CoNS], 19 patients), Staphylococcus aureus (7 patients), and P. acnes (6 patients) predominated. The addition of anaerobic cultures and prolonged incubation times increased the verification of shunt infection by more than one third. Children with P. acnes infection were significantly older, had a lower body temperature, fewer cerebrospinal fluid (CSF) leukocytes, a higher CSF/blood glucose ratio, more distal catheter infections, and other sources of infection. Four had an abdominal pseudocyst. Children < 1 year of age and infected with CoNS were more affected than older children with systemic and local symptoms. In children with distal catheter infection and growth of propionibacteria at the time of the distal catheter and valve replacement, no follow-up antibiotic treatment was necessary.

CONCLUSIONS

Addition of anaerobic cultures and prolonged incubation times led to an increase in the detection of shunt infections. Infections caused by propionibacteria often result in mild symptoms that may be overlooked if adequate anaerobic cultures are not obtained.

Cerebrospinal fluid eosinophilia in children with ventricular shunts

OBJECT

Eosinophils have been reported in children with cerebrospinal fluid (CSF) shunts. The goal of this study was to describe the risk factors, relationship to infection, and clinical significance of CSF eosinophilia in a large group of shunt-treated patients.

METHODS

The authors performed a retrospective review of data obtained in all patients who underwent ventricular shunt placement or revision at the James Whitcomb Riley Hospital for Children between 2000 and 2004.

RESULTS

Eosinophils were identified during a follow-up shunt evaluation in 93 (31%) of 300 patients after initial shunt placement. Eosinophilia was statistically related to CSF extravasation (p < 0.0001), shunt infection (p = 0.031), blood in CSF (p < 0.0001), younger age at shunt insertion (p = 0.030), and the diagnosis of posthemorrhagic hydrocephalus (p < 0.0001). Patients with CSF eosinophilia had a higher risk of subsequent shunt failure (p < 0.0001). Analysis was performed using data obtained in a cohort of patients with a total of 130 shunt infections. Cerebrospinal fluid eosinophils were identified in 118 infections (90.8%). The leukocytic and eosinophilic reactions were dependent on the infecting organism. Propionibacterium acnes had a statistically lower CSF leukocyte count but higher differential percentage of eosinophils than the other common pathogens.

CONCLUSIONS

Cerebrospinal fluid eosinophilia is a relatively common finding in children with shunts. Patients with CSF eosinophilia had an increased risk of shunt malfunction in the present series. Eosinophilia is associated with infection, CSF extravasation, and blood in the CSF. Patients with P. acnes-induced shunt infections have higher eosinophil percentages than are found in infections associated with other common organisms. Therefore, in patients with eosinophilia, extended anaerobic culture studies should be performed with particular attention paid to searching for this pathogen.

Ventriculo-peritoneal shunt infections in infants and children

OBJECTIVE

To determine the rate and the type of ventriculoperitoneal (VP) shunt infections in infants and children admitted to King Fahad Hofuf hospital of Al-Ahsaa area at the Eastern Province of Saudi Arabia.

METHODS

From mid 2003 to end of 2006; VP shunt infection episodes were reviewed. Once infection was suspected, a cerebrospinal fluid (CSF) sample was taken and empirical antibiotics were recommended. Once infection was confirmed, VP shunt was removed and external ventricular drainage (EVD) was inserted until CSF became sterile after which a new shunt was inserted.

RESULTS

25.9% of patients with VP shunts had infections which represents 29.3% of the procedures. 40% of infected patients had recurrent episodes. 59.1% of infections occurred throughout the first two months following insertion. Single pathogen was isolated in each episode. Pseudomonas auerginosa represented 50% of isolated pathogens compared with 18.2% with Staphylococcus epidermidis.

CONCLUSIONS

There is a high incidence of VP shunt infections in King Fahad Hofuf hospital when compared with other international centres. Gram negative organisms are the most common cause of the infection.

Sterile surgical technique for shunt placement reduces the shunt infection rate in children: preliminary analysis of a prospective protocol in 115 consecutive procedures

OBJECTIVE

The objective of this study was to evaluate whether the rigid application of a sterile protocol for shunt placement was applicable on a routine basis and allowed the reduction of shunt infections (SI) in children.

MATERIALS AND METHODS

Since 2001, a rigid sterile protocol for shunt placement in children using neither antibiotic-impregnated catheters nor laminar airflow was prospectively applied at Erasme Hospital, Brussels, Belgium. For assessing the protocol efficacy before continuation, we preliminarily analyzed the results of the first 100 operated children (43 females, 57 males, 49 aged <12 months; 115 consecutive shunt placement/revision procedures). All procedures were performed by the same senior surgeon, one assistant, one circulating nurse, one anesthesiologist. The sterile protocol was rigidly imposed to these four staff members: uniformed surgical technique; limited implant and skin edge manipulation; minimized human circulation in the room; scheduling surgery as first morning operation; avoiding postoperative cerebrospinal fluid (CSF) leak; double gloving; procedures of less than 30-min duration; systemic antibiotics prophylaxis. We analyzed separately: (1) children carrying an increased risk of SI (n = 38) due to preoperative external ventricular drainage, CSF leak, meningitis, glucocorticoids, chemotherapy; (2) children aged <12 months; (3) procedures for shunt revision.

RESULTS

Errors in protocol application were recorded in 71/115 procedures. They were mainly done by non-surgical staff, decreased with time and were medically justified in some young children. Surprisingly, no SI occurred (follow-up, 4 to 70 months). One child developed an appendicitis with peritonitis (Streptococcus faecalis) after 6 months. No SI was found. After peritonitis was cured, shunt reinsertion was uneventful.

CONCLUSION

These preliminary results suggest that a uniform and drastic sterile surgical technique for shunt placement: (1) can be rigidly applied on a routine basis; (2) can lower the early SI rate below 1%; (3) might have a stronger impact to reduce SI than using antibiotic-impregnated catheters and optimizing the operative environment such as using laminar airflow and reducing the non-surgical staff. This last issue will be evaluated further in the present ongoing protocol.

Spontaneous bacterial peritonitis causing Serratia marcescens and Proteus mirabilis ventriculoperitoneal shunt infection. Case report

The authors report their experience treating a polymicrobial ventriculoperitoneal (VP) shunt infection in a developmentally delayed 21-year-old woman. Cerebrospinal fluid (CSF) cultures grew Serratia marcescens and Proteus mirabilis. On admission and throughout her hospitalization, results of physical examination of her abdomen were normal, and radiographic studies showed no evidence of bowel perforation or pseudocyst formation. Contrast-enhanced computed tomography of the abdomen revealed a small fluid collection. After a course of intravenous gentamicin and imipenem with cilastatin in conjunction with intrathecal gentamicin, the infection was resolved and the VP shunt was reimplanted. Although VP shunt infections are not uncommon, S. marcescens as a causative agent is exceedingly rare and potentially devastating. Only two previous cases of S. marcescens shunt infection have been reported in the literature. Authors reporting on S. marcescens infections in the central nervous system (CNS) have observed significant morbidity and death. Although more common, the presence of P. mirabilis in the CSF is still rare and highly suggestive of bowel perforation, which was absent in this patient. Spontaneous bacterial peritonitis was the likely source from which these bacteria gained entrance into the VP shunt system, eventually causing ventriculitis in this patient. The authors conclude that in light of the high morbidity associated with S. marcescens infection of the CNS, intrathecal administration of gentamicin should be strongly considered as part of first-line therapy for S. marcescens infections in VP shunts.

Hospitalist care of the medically complex child

The nature of inpatient pediatrics is changing. Over the past decade, several factors have converged to influence the kinds of children currently being hospitalized. There has been a shift in the relative proportion of otherwise healthy children with acute illnesses being hospitalized to children with increasing medical complexity. This article focuses on hospitalist care of medically complex children and provides an overview on (1) the challenges in defining this population, (2) the unique issues surrounding their inpatient care (using a family-centered care approach that includes coordinated care, minimizing secondary complications, nutritional needs, functional limitations, transdisciplinary collaboration, and primary care issues), (3) technology devices commonly found, and (4) a proposal for a research agenda regarding medically complex children.

Intraventricular antibiotics for bacterial meningitis in neonates

BACKGROUND

Neonatal meningitis may be caused by bacteria, especially gram-negative bacteria, which are difficult to eradicate from the cerebrospinal fluid (CSF) using safe doses of antibiotics. In theory, intraventricular administration of antibiotics would produce higher antibiotic concentrations in the CSF than intravenous administration alone, and eliminate the bacteria more quickly. However, ventricular taps may cause harm.

OBJECTIVES

To assess the effectiveness and safety of intraventricular antibiotics (with or without intravenous antibiotics) in neonates with meningitis (with or without ventriculitis) as compared to treatment with intravenous antibiotics alone.

SEARCH STRATEGY

MEDLINE, EMBASE, The Cochrane Library, Issue 2, 2004, Science Citation Index, and the Oxford Database of Perinatal Trials were searched in June 2004. Pediatric Research (abstracts of proceedings) were searched (1990 - April 2004) as were reference lists of identified trials and personal files. No language restrictions were applied.

SELECTION CRITERIA

Selection criteria for study inclusion were: Randomized or quasi-randomized controlled trials in which intraventricular antibiotics with or without intravenous antibiotics were compared with intravenous antibiotics alone in neonates (< 28 days old) with meningitis. One of the following outcomes was required to be reported: mortality during initial hospitalization, neonatal and/or infant mortality, neurodevelopmental outcome, duration of hospitalization, duration of culture positivity of CSF and side effects.

DATA COLLECTION AND ANALYSIS

All reviewers abstracted information for outcomes reported and one reviewer checked for discrepancies and entered data into RevMan 4.2. Relative risk (RR), risk difference (RD), number needed to treat (NNT) or number needed to harm (NNH), and mean difference (MD), using the fixed effects model are reported with 95% confidence intervals (CI). The fixed effect model was used for meta-analysis.

MAIN RESULTS

One study was included in the review. This study assessed the effect of intraventricular gentamicin in a mixed population of neonates (69%) and older infants (31%) with gram negative meningitis and ventriculitis. Mortality was statistically significantly higher in the group that received intraventricular gentamicin in addition to intravenous antibiotics compared to the group receiving intravenous antibiotics alone [RR 3.43 (95% CI, 1.09, 10.74; RD 0.30 (95% CI, 0.08, 0.53); NNH was 3 (95% CI; 2 ,13)]. Duration of CSF culture positivity did not differ significantly (MD -1.20 days (95% CI, -2.67, 0.27).

REVIEWERS' CONCLUSIONS

In one trial, enrolling infants with gram negative meningitis and ventriculitis, the use of intraventricular antibiotics in addition to intravenous antibiotics resulted in a 3 fold increased RR for mortality compared to standard treatment with intravenous antibiotics alone. Based on this result, intraventricular antibiotics as tested in this trial should be avoided. Further trials comparing these interventions are not justified in this population.

Treatment of cerebrospinal fluid shunt infections: a decision analysis

BACKGROUND

Cerebrospinal fluid shunts transfer cerebrospinal fluid (CSF) from the lateral ventricles in the brain to the peritoneum (ventriculoperitoneal shunt) or the right atrium (ventriculoatrial shunt) via subcutaneous Silastic tubing. As with any implanted foreign body, infection is a serious complication. Although there are several therapeutic modalities currently used for the treatment of shunt infections, controversy remains as to which is best given that there has been only one randomized trial comparing their effectiveness.

OBJECTIVE

To determine which treatment modality is most effective by using decision analysis to compare three approaches with regard to cure rate, morbidity and mortality.

METHODS

We constructed a decision tree to map out the different treatment modalities and assigned probability values obtained from previously published studies. A utility value was assigned to each treatment outcome, ranging from 0 to 1.0, with a higher score indicating a more favorable outcome. Calculations were performed using Decision Analysis TreeAge computer software.

RESULTS

The removal of an infected shunt with establishment of external ventricular drainage or ventricular taps and administration of antibiotics leads to the highest expected value, 0.86. Removal of an infected shunt followed by immediate replacement and administration of antibiotics is less effective, with an expected value of 0.76. The use of antibiotics alone results in the lowest expected value, 0.61. Sensitivity analysis showed the above findings to be robust with respect to clinically relevant changes for the baseline probabilities and utility values.

CONCLUSION

A protocol of shunt removal, external ventricular drainage placement or ventricular taps and antibiotics, followed by creation of a new shunt when CSF sterility is achieved, is the most effective method of treatment for CSF shunt infection.

Meningitis and shunt infection caused by anaerobic bacteria in children

This review describes the microbiology and management of meningitis and shunt infections caused by anaerobic bacteria in children. The predominant anaerobes recovered in meningitis are Bacteriodes spp., Bacteriodes fragilis, Fusobacterium spp., and Clostridium spp. Peptostreptococcus, Veillonella, Actinomyces, Propionibacterium acnes, and Eubacterium are less commonly isolated. The predisposing conditions for meningitis are acute or chronic middle-ear infection, sinusitis, pharyngitis, and pulmonary infections. In newborn and preterm infants the predisposing conditions are rupture of membranes, amnionitis, fetal distress, necrotizing enterocolitis, gastric perforation and subsequent ileus followed by bacteremia, aspiration pneumonitis and septicemia, infected ventriculoperitoneal or ventriculoatrial shunt, and complicating dermal sinus tract infections. Shunt infection with Propionibacterium spp. has been reported in children, especially in association with ventriculoauricular and ventriculoperitoneal shunts. Clostridium perfringens has been recovered from infants with a ventriculoperitoneal shunt. Multiple-organism meningitis was reported as a complication of ventriculoperitoneal and lumboperitoneal shunts that perforated the gastrointestinal tract. Early recognition and effective therapy are essential to recovery. Management of meningitis includes the use of antimicrobials effective against anaerobes that penetrate the blood-brain barrier. These include metronidazole, chloramphenicol, the combination of a penicillin and a beta-lactamase inhibitor, and carbapenems. The treatment of shunt infection includes antimicrobial therapy and removal of the shunt.

Laboratory diagnosis of central nervous system infections

The laboratory diagnosis of CNS infection is essential for optimal therapy. Acute infection requires rapid turn-around testing with high predictive values, that is, the ability of a test to accurately identify those patients who do or do not have disease caused by a specific etiology. The Gram's stain, fungal stains of direct smears, antigen testing for C. neoformans, and culture of bacteria, fungi, mycobacteria, and some viruses are important tests for the diagnosis of acute infection. The laboratory diagnosis of chronic infection necessitates discussion between the clinician and laboratory technician to allow triaging of testing. Antigen tests for bacteria, fungi, and viruses; antibody tests for multiple microorganisms; and PCR testing for bacteria, M. tuberculosis, and many viruses are all important in limited clinical situations. All testing for acute or chronic disease depends on sufficient specimen that is transported to the laboratory in a manner that will not compromise viability or chemical integrity. Sterile containers that maintain moisture content, exclude oxygen for anaerobic requests, and are stored at proper temperatures (22 degrees C room, 4 degrees C refrigeration, or -20 degrees C freezer depending on pathogen and test) are mandatory. Many laboratory issues addressing the diagnosis of CNS infection are changing or evolving. Most important is the recognition that bacterial antigen testing for the diagnosis of acute bacterial meningitis rarely impacts patient management and is not routinely needed, CSF shunt infections differ from usual meningeal infections and require rapid diagnosis, and TB meningitis remains a difficult disease to diagnosis but may be confirmed first by PCR testing of CSF. In addition, Whipple's disease of the CNS can be confirmed using PCR with CSF; CJD has a marker protein, referred to as 14-3-3 antigen, that can be detected in CSF, and the diagnosis of fungal CNS disease requires careful interpretation of direct smears, antigen and antibody testing, and culture. Most difficult to diagnose among the CNS infections are viral meningitis and encephalitis. The appearance of new etiologies, such as West Nile virus, and the common use of PCR for the herpes viruses and enteroviruses represent important advances. Evolving methods for the laboratory diagnosis of CNS infection represent significant improvements over previous testing; however, the array of tests available demands more attention for appropriate selection, is significantly more expensive, and requires new skills for performance and interpretation. The responsibility for proper use of laboratory testing lies both with the clinician and laboratory technician.

Transient diabetes insipidus following Escherichia coli meningitis complicated by ventriculoperitoneal shunt

Although disorders of ADH secretion associated with meningitis are usually consistent with the Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH), central diabetes insipidus (DI) is an exceptional complication of meningitis. Transient DI as a complication of Escherichia coli (E. coli) meningitis due to ventriculoperitoneal shunt in an 18-month-old boy is presented. Blood and spinal fluid cultures yielded E. coli, sensitive to cefotaxime. The DI arose on the day 3 after admission and continued to the day 20. Treatment comprised cefotaxime, dexamethasone, fluid adjustment and vasopressin. The course of our case supports that in cases of bacterial meningitis, initial fluid restriction may occasionally result in dangerous conditions. Therefore, all children with bacterial meningitis should be followed closely not only in terms of SIADH but also DI. To our knowledge this is the first transient DI associated with E. coli-caused meningitis case reported.

Cerebral ventricular shunts

Cerebral ventricular shunts are siphoning devices used to treat hydrocephalus. They are placed within cerebral ventricles and peripheral cavities such as the ventricular atrium or peritoneal cavity. Complications include obstruction of cerebral spinal fluid (malfunction) and infection. Morbidity and mortality rates are high when shunt malfunction and infection are not treated emergently. This report summarizes the physical examination of patients with ventricular shunts, reviews the type of shunts commonly used, discusses shunt malfunctions (causing overshunting or undershunting of cerebrospinal fluid) and infections, and makes recommendations concerning empiric antibiotic therapy for shunt infection. The technique of tapping a shunt is presented for management of patients with elevated intracranial pressure that does not respond to non-invasive maneuvers to lower the pressure.

Intracerebral sepsis due to intestinal perforation by ventriculo-peritoneal shunts: two cases

Two cases of ventriculo-peritoneal (V-P) shunt infection attributable to intestinal perforation are reported. One patient developed a brain abscess, the other ventriculitis. Microbiology consisted of faecal flora and the peritoneal catheter was found to be faecally stained in both cases. There were no abdominal symptoms or signs. It is likely that infection developed via the ascending route.