Intracranial pressure monitors. Epidemiologic study of risk factors and infections

Pathophysiology and Prevention of Ventriculostomy-Related Infections: A Review

This qualitative review aims to summarize current knowledge on ventriculostomy-related infection (VRI) pathophysiology and its prevention. VRI generally occurs at day 10, mainly because of Gram-positive cocci , after a cerebrospinal fluid leak. Skin microbiota and biofilm seem to play a major role in VRI pathogenesis. Colonization of external ventricular drain by biofilm is universal and occurs quickly after catheter insertion. However, pathogens from the skin are more often associated with VRI than commensal bacteria. A review of proposed preventive measures shows that none has proven to be fully efficient. Periprocedural and prolonged systemic prophylactic antimicrobials have not shown to prevent VRIs and may promote the emergence of more resistant or pathogenic strains. Antimicrobial and silver-impregnated external ventricular drains, although promising, have not demonstrated preventive effects and may modify bacterial ecology. These results are consistent with the proposed pathophysiology. Finally, we will present a few propositions for future research that may help in improving our knowledge and thus better prevent VRIs. Until then, given the available data, limiting the duration of ventricular drainage may be the most attainable option to prevent VRIs.

Invasive and Noninvasive Techniques for Intracranial Pressure Monitoring After Decompressive Craniectomy: A Systematic Review and Meta-Analysis

The use of invasive or noninvasive intracranial pressure (ICP) monitoring post-decompressive craniectomy (DC) has been a continuous matter of debate. Accordingly, this meta-analysis aims to examine the existing evidence of both approaches and compare their impact among patients undergoing DC, guiding clinical decision-making in the management of elevated ICP. The databases used were Pubmed, Cochrane, Web of Science, and Embase. Inclusion criteria included: (1) English studies; (2) randomized and nonrandomized studies; (3) reporting on invasive OR noninvasive ICP monitoring after DC; (4) with at least one of the outcomes of interest: incidence of mortality, new cerebral hemorrhages, and the Glasgow Outcome Scale. The study followed the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Thirty-six studies were included in this meta-analysis, resulting in a sample of 1624 patients. One thousand two hundred eighty-six underwent invasive monitoring, and 338 underwent noninvasive methods. In the invasive group, a mortality rate of 17% (95% confidence interval [CI]: 12%-22%), a good outcome rate of 58% (95% CI: 38%-49%), a poor outcome rate of 42% (95% CI: 21%-62%), and an overall incidence of new hemorrhages of 4% (95% CI: 0%-8%) were found. Whereas in the noninvasive sample, a mortality rate of 20% (95% CI: 15%-26%) and a good outcome rate of 38% (95% CI: 25%-52%) were obtained. It seems that the effectiveness of invasive and noninvasive ICP monitoring methods are comparable in post-DC patients. While invasive monitoring remains gold standard, noninvasive methods offer a safer and cost-effective alternative, potentially improving post-DC patient care, and can mostly be used simultaneously with invasive methods.

An update on a persisting challenge: A systematic review and meta-analysis of the risk factors for surgical site infection post craniotomy

BACKGROUND

Surgical site infections (SSIs) postcraniotomy continue to impose a significant burden on health care systems and patient outcomes. It is, therefore, important to understand their risk factors in order to promote effective preventative measures. This meta-analysis aims to provide a comprehensive, up-to-date analysis of the risk factors associated with SSIs in neurosurgical procedures.

METHODS

A systematic review was conducted as per preferred reporting items for systematic reviews and meta-analysis guidelines to explore existing primary evidence on the risk factors for SSIs postcraniotomy. A comprehensive search of MEDLINE, EMBASE, and Pubmed was performed from database inception up to June 2023. 43 studies were included in the meta-analysis, encompassing a total of 68,881 patients.

RESULTS

The strongest predictor for SSIs was found to be cerebrospinal fluid (CSF) leak (OR: 8.91, CI: 4.30-18.44). Other significant factors included infratentorial surgery (OR: 0.43, CI: 0.31-0.61), emergency surgery (OR: 1.41, CI: 1.05-1.91), reintervention (OR: 3.19, CI: 1.77-5.75), prolonged operative time (mean difference: 33.25; CI: 18.83-47.67), hospital length of stay (mean difference: 0.60; CI: 0.23-0.98) and intracranial pressure monitor (ICPM) insertion (OR: 1.81; CI: 1.06-3.11). Contrarily, sex, body mass index (BMI), diabetes, antibiotic prophylaxis, immunosuppressive agents, trauma, use of artificial implants did not demonstrate statistical significance.

CONCLUSIONS

This meta-analysis provides an up-to-date and comprehensive evaluation of risk factors for SSIs postcraniotomy. It emphasizes the need for preventive strategies, particularly against CSF leaks, and calls for further research to elucidate the intricate relationships between these factors.

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

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

Ventriculitis: Infection or Inflammation

Ventriculitis, or infection of the cerebrospinal fluid, in the presence of external ventricular drains (EVD), is an important complication and associated with substantial mortality, morbidity, and healthcare costs. Further, the conditions that require the insertion of an EVD, such as neurotrauma and subarachnoid hemorrhage, are themselves associated with inflammation of the cerebrospinal fluid. Phenotypically, patients with inflammation of the cerebrospinal fluid can present with very similar symptoms, signs, and laboratory findings to those with infection. This review examines various controversies relating to the definitions, diagnosis, challenges of differentiating infection from inflammation, prevention, and treatment of ventriculitis in patients with EVDs.

Use of emerging technologies to enhance the treatment paradigm for spontaneous intraventricular hemorrhage

The presence of intraventricular hemorrhage (IVH) portends a worse prognosis in patients presenting with spontaneous intracerebral hemorrhage (ICH). Intraventricular hemorrhage increases the rates of hydrocephalus, ventriculitis, and long-term shunt dependence. Over the past decade, novel medical devices and protocols have emerged to directly treat IVH. Presently, we review new technological adaptations to treating intraventricular hemorrhage in an effort to focus further innovation in treating this morbid neurosurgical pathology. We summarize current and historical treatments as well as innovations in IVH including novel procedural techniques, use of the Integra Surgiscope, use of the Artemis evacuator, use of BrainPath, novel catheter technology, large bore external ventricular drains, the IRRAflow, the CerebroFlo, and the future directions of the field. Technology and medical devices for both surgical and nonsurgical methods are advancing the treatment of IVH. With many promising new technologies on the horizon, prospects for improved clinical care for IVH and its etiologies remain hopeful.

Intracranial Pressure During the Development of Renovascular Hypertension

[Figure: see text].

Decreasing External Ventricular Drain Infection Rates in the Neurocritical Care Unit: 12-Year Longitudinal Experience at a Single Institution

OBJECTIVE

External ventricular drain (EVD) placement is a common neurosurgical procedure, and EVD-related infection is a significant complication. We examined the effect of infection control protocol changes on EVD-related infection incidence.

METHODS

Changes in EVD placement protocol and incidence density of infections after implementation of protocol changes in the neurocritical care unit were tracked from 2007 to 2019. EVD infections were defined using a modified U.S. Centers for Disease Control and Prevention National Healthcare Safety Network surveillance definition of meningitis/ventriculitis for patients with EVDs in situ for at least 2 days confirmed by positive culture. Contribution of protocol changes to EVD infection risk was assessed via multivariate regression.

RESULTS

Fifteen major changes in EVD protocol were associated with a reduction in infections from 6.7 to 2.0 per 1000 EVD days (95% confidence interval [CI], 4.1-5.3; P < 0.001). Gram-positive bacterial infection incidence decreased from 4.8 to 1.7 per 1000 EVD days (95% CI, 2.3-3.9; P = 0.00882) and gram-negative infection incidence decreased from 1.9 to 0.5 per 1000 EVD days (95% CI, 0.6-2.3; P = 0.0303). Of all protocol changes since 2007, the largest reduction in incidence was 3.9 infections per 1000 days (95% CI, 0.50-7.30; P = 0.011), associated with combined standardization of reduced EVD sampling frequency, cutaneous antisepsis with alcoholic chlorhexidine before EVD placement, and use of a subcutaneous tunneling technique during EVD insertion.

CONCLUSIONS

The most significant reduction in EVD infections may be achieved through the combination of reducing EVD sampling frequency and standardizing alcoholic chlorhexidine cutaneous antisepsis and subcutaneous tunneling of the EVD catheter.

Assessment of Bacterial Colonization of Intracranial Pressure Transducers: A Prospective Study

OBJECTIVES

Cerebral infections related to the presence of an intraparenchymal intracranial pressure transducer (ICPT) are rare. We assessed the incidence of ICPT-related infections and colonization using culture, molecular biology, and electron microscopy.

METHODS

All consecutive patients in a neurosurgical intensive care unit who had an ICPT inserted between March 2017 and February 2018 were prospectively included. Presence of colonization on the ICPTs was assessed after removal using culture, scanning electron microscopy (SEM), and next-generation sequencing (NGS).

RESULTS

Fifty-three ICPTs (53 patients), indwelling for a median of 4 (range 3-7) days, were studied. Median patient follow-up was 3 months. SEM, microbial culture, and NGS were performed for 91%, 79%, and 72% of ICPTs, respectively; 28 ICPTs (53%) were assessed using all three techniques. No patient developed ICPT-related infection. Microbial cultures were positive for two of the ICPTs (5%); colonization was identified on all ICPTs using NGS and SEM. Mature biofilm was observed on 35/48 (73%) of ICPTs. A median of 10 (8-12) operational taxonomic units were identified for each ICPT, most being of environmental origin. There was no association between biofilm maturity and antimicrobial treatment or duration of ICPT insertion. Antimicrobial treatment was associated with decreased alpha and beta-diversity (p = 0.01).

CONCLUSIONS

We observed no ICPT-related cerebral infections although colonization was identified on all ICPTs using NGS and SEM. Mature biofilm was the main bacterial lifestyle on the ICPTs.

Fibrinolytics and Intraventricular Hemorrhage: A Systematic Review and Meta-analysis

Intraventricular hemorrhage (IVH) is an independent poor prognostic factor in subarachnoid and intra-parenchymal hemorrhage. The use of intraventricular fibrinolytics (IVF) has long been debated, and its exact effects on outcomes are unknown. A systematic review and meta-analysis were performed in accordance with the PRISMA guidelines to assess the impact of IVF after non-traumatic IVH on mortality, functional outcome, intracranial bleeding, ventriculitis, time until clearance of third and fourth ventricles, obstruction of external ventricular drains (EVD), and shunt dependency. Nineteen studies were included in the meta-analysis, totaling 1020 patients. IVF was associated with lower mortality (relative risk [RR] 0.58; 95% confidence interval [CI] 0.47-0.72), fewer EVD obstructions (RR 0.41; 95% CI 0.22-0.74), and a shorter time until clearance of the ventricles (median difference [MD] - 4.05 days; 95% CI - 5.52 to - 2.57). There was no difference in good functional outcome, RR 1.41 (95% CI 0.98-2.03), or shunt dependency, RR 0.93 (95% CI 0.70-1.22). Correction for publication bias predicted an increased risk of intracranial bleeding, RR 1.67 (95% CI 1.01-2.74) and a lower risk of ventriculitis, RR 0.68 (95% CI 0.45-1.03) in IVH patients treated with IVF. IVF was associated with improved survival, faster clearance of blood from the ventricles and fewer drain obstructions, but further research is warranted to elucidate the effects on ventriculitis, long-term functional outcomes, and re-hemorrhage.

Decreasing External Ventricular Drain-Related Infection Rates with Duration-Independent, Clinically Indicated Criteria for Drain Revision: A Retrospective Study

OBJECTIVE

To lower external ventricular drain (EVD)-related infection rates, in April 2013, our institution enacted a major protocol change, switching from routine EVD replacement every 5 days to EVD replacement only when clinically indicated. In the present study, we evaluated the effect of this change on nosocomial EVD-related infections.

METHODS

We performed a retrospective cohort study to compare the EVD-related infection rates between 2 groups (group A, elective EVD replacement; group B, clinically indicated EVD replacement). We analyzed the data from 142 patients (group A, n = 43; group B, n = 99), with a total of 227 EVDs for 5 years and 3 months (1721 catheter days).

RESULTS

The overall EVD-related infection rates were elevated in group A (0.14; 32% of patients) compared with group B (0.08; 8%; P = 0.001). The median hospital stay (33 vs. 24 days; P = 0.001) and neurosurgical intensive care unit stay (30.5 vs. 17 days; P < 0.0001) were also longer for group A. The requirement for multiple EVDs was an independent risk factor (P = 0.003), with a 4.6 times greater risk in group A (odds ratio, 4.64; 95% confidence interval, 1.7-12.6).

CONCLUSIONS

The findings from our study strengthen an increasing body of evidence suggesting the importance of inoculation of skin flora as a critical risk factor for EVD-related infections, underscoring the importance of drain changes only when clinically indicated and that, as soon as clinically permitted, catheters should be removed.

Peripheral white blood cell count as a screening tool for ventriculostomy-related infections

One of the most common complications following external ventricular drain (EVD) placement is infection. Routine cultures of cerebrospinal fluid (CSF) are often used to screen for infection, however several days may pass before infection is discovered. In this study, we compared the predictive value of daily recorded vital sign parameters and peripheral white blood count (WBC) in identifying ventriculostomy-related infections. Patients with EVDs who had CSF cultures for microorganisms performed between January 2011 and July 2017 were assigned to either an infected and/or uninfected study group. Clinical parameters were then compared using t-test, chi squared and multiple logistic regression analyses. Patients of any age and gender were included. One hundred seventy uninfected and 10 infected subjects were included in the study. Nine of the 10 infected patients had an elevated WBC (>10.4 × 10³/μL), with a significantly greater WBC (15.9 × 10³/μL) than the uninfected group (10.4 × 10³/μL) (p-value ≤ 0.0001). Using logistic regression, we found no association between patient vital signs and CSF infection except for WBC (p = .003). As a diagnostic marker for CSF infection, the sensitivity and specificity of WBC elevation greater than 15 × 10³/μL was 70% (7/10) and 90.2% (147/163), respectively. This study serves as a 'proof of concept' that WBC could be useful as potential screening tool for early detection of CSF infection post-EVD placement. Future investigation using a large, multicenter prospective study is needed to further assess the applicability of this parameter.

Risk factors for meningitis in neurosurgical patients with cerebrospinal fluid drains: prospective observational cohort study

BACKGROUND

Cerebrospinal fluid (CSF) drainage or intracranial pressure (ICP) monitoring devices are life-saving devices. We examined the risk factors for infections related to them and assessed the effect of an infection control (IC) intervention.

METHODS

A prospective observational study was conducted in the Neurosurgical Department of our hospital between 2014 and 2017. We included all consecutive patients undergoing CSF catheter insertions, including external ventricular drainage (EVD), lumbar drainage (LD), and ICP catheters. An IC intervention was implemented between March and August 2016. We examined risk factors for meningitis or ventriculitis, defined according to Healthcare-associated infections surveillance definitions, on univariate and multivariate analysis.

RESULTS

A total of 232 patients with 437 drains (212 EVDs, 92 LDs, and 133 ICPs) were included. On univariate and multivariate analysis, the infection incidence was 13.7 per 1000 drain days (17.3/1000 before IC intervention, 7.9/1000 during, and 9.2/1000 after the intervention). Most episodes were caused by Gram-negative bacteria, and the most common pathogen was Acinetobacter baumanii. Risk factors for infection per patient included diabetes mellitus (p = 0.017), CSF leak (p = 0.032), drain opening (p = 0.027), and the duration of the drain in days (p = 0.035). Risk factors per catheter included drain opening (p < 0.001), drain days (p = 0.001), and the IC intervention period compared to before the intervention period (p = 0.037). When restricting the analysis to EVDs, drain days (p = 0.001) was the only significant risk factor.

CONCLUSIONS

Strict adherence to IC, shortening drain duration, and avoiding unnecessary opening and manipulation of the drains are crucial to preventing neurosurgical drain infections.

Management of traumatic brain injury patients

Traumatic brain injury (TBI) has been called the ‘silent epidemic’ of modern times, and is the leading cause of mortality and morbidity in children and young adults in both developed and developing nations worldwide. In recent years, the treatment of TBI has undergone a paradigm shift. The management of severe TBI is ideally based on protocol-based guidelines provided by the Brain Trauma Foundation. The aims and objectives of its management are prophylaxis and prompt management of intracranial hypertension and secondary brain injury, maintenance of cerebral perfusion pressure, and ensuring adequate oxygen delivery to injured brain tissue. In this review, the authors discuss protocol-based approaches to the management of severe TBI as per recent guidelines.

Risk factors of neurosurgical site infection after craniotomy: A systematic review and meta-analysis

BACKGROUND

Neurosurgical site infection (SSI) is a complication related to craniotomy, which may lead to severe morbidity and higher hospital costs during the postoperative period.

METHODS

Retrospective cohorts, case-control studies, or prospective investigations addressing risk factors of SSI updated until January 2017 were systematically searched in 2 databases (PubMed and Embase). The Newcastle-Ottawa Scale was used to evaluate quality of the included studies, heterogeneity was assessed by I² tests, and a funnel plot and Egger test were used for the evaluation of publication bias.

RESULTS

There were 26 studies in total enrolled in this review. The results showed that the risk factors which had relation with SSI were other infection (odds ratio [OR], 5.42; 95% confidence interval [CI], 2.8-10.49), number of operations (>1) (OR, 2.352; 95% CI, 1.142-4.847), cerebrospinal fluid (CSF) leak (OR, 7.817; 95% CI, 2.573-23.751), CSF drainage (OR, 2.55; 95% CI, 1.58-4.11), duration of operation (>4 hours) (as for retrospective cohort studies) (OR, 1.766; 95% CI, 1.110-2.809), venous sinus entry (OR, 4.015; 95% CI, 1.468-10.982), American Society of Anesthesiologists score (>2) (OR, 1.398; 95% CI, 1.098-1.78), sex (male) (as for prospective investigations) (OR, 1.474; 95% CI, 1.013-2.145), and surgical reasons (nontraumatic) (OR, 2.137; 95% CI, 1.106-4.129).

CONCLUSIONS

According to the current analysis, all the factors mentioned were the risk factors for SSI after craniotomy. Patients with these risk factors should be paid more attention to prevent SSI. More evidence provided by high-quality studies is still needed to further investigate the risk factors of SSI.

Polymerase chain reaction based detection of bacterial 16S rRNA gene in the cerebrospinal fluid in the diagnosis of bacterial central nervous system infection in the course of external cerebrospinal fluid drainage. Comparison with standard diagnostics currently used in clinical practice

BACKGROUND AND PURPOSE

External drainage of cerebrospinal fluid (CSF) is a commonly used neurosurgical procedure. Complications of the procedure comprise central nervous system (CNS) bacterial infections, the frequency of which is estimated at around 6-10%. Detection of these infections is ineffective in many cases. The aim of the study was to evaluate the usefulness of a polymerase chain reaction (PCR)-based detection of bacterial 16S rRNA gene (16S rDNA) in the CSF.

MATERIAL AND METHODS

The study group consisted of 50 patients. Clinical signs of CNS infection were monitored and routine laboratory and microbiological tests were performed. The results of standard methods were compared with the bacterial 16S rDNA detection.

RESULTS

Using cultures, CNS infection was diagnosed in 8 patients, colonization of the drainage catheter in 6 patients, and sample contamination in 7 patients. In the group of the remaining 29 patients, no positive CSF culture was obtained and 13 of these patients also had all negative results for 16S rDNA detection. For the remaining 16 patients of this group, CNS infection, colonization of the catheter and sample contamination were diagnosed via PCR alone. Routine biochemical CSF tests and blood inflammatory parameters had a supporting value.

CONCLUSIONS

Routine hospital tests do not provide rapid and efficient detection of the external drainage related bacterial CNS infection. It is justified to use several diagnostic methods simultaneously. The16S rDNA determination in CSF can increase the probability of detection of possible pathogens.

Will clinical parameters reliably predict external ventricular drain-associated ventriculitis: Is frequent routine cerebrospinal fluid surveillance necessary?

Background:

The placement of an external ventricular drain (EVD) for monitoring and treatment of increased intracranial pressure is not without risk, particularly for the development of associated ventriculitis. The goal of this study was to investigate whether changes in cerebrospinal fluid (CSF), serum, or clinical parameters are correlated with the development of ventriculitis before it occurs, allowing for the determination of optimal timing of CSF collection.

Methods:

An observational retrospective study was conducted between January 2006 and May 2012. A total of 466 patients were identified as having an in-situ EVD placed. Inclusion criteria were age >18 years, glasgow coma scale (GCS) 4-15, and placement of EVD for any indication. Exclusion criteria included recent history of meningitis, cerebral abscess, cranial surgery or open skull fracture within the previous 30 days. A broad definition of ventriculitis was used to separate patients into three initial categories, two of which had sufficient patients to proceed with analysis: suspected ventriculitis and confirmed ventriculitis. CSF sampling was conducted on alternating weekdays.

Results:

A total of 466 patients were identified as having an EVD and 123 patients were included in the final analysis. The incidence of ventriculitis was 8.8%. Only the ratio of glucose CSF: serum <0.5 was found to be of statistical significance, though not correlated to developing a ventriculitis.

Conclusions:

This study demonstrates no reliable tested CSF, serum, or clinical parameters that are effectively correlated with the development of ventriculitis in an EVD patient. Thus, we recommend and will continue to draw CSF samples from patients with in-situ EVDs on our current schedule for as long as the EVD remains in place.

Tension pneumocephalus as a complication of intracranial pressure monitoring: A case report

Intracranial pressure monitoring has become routine in the management of severe head injuries. We describe an unusual complication secondary to intracranial pressure monitoring with subdural cup catheter. A 35 year-old man was admitted to the Neurosurgery Department following blunt head trauma. He underwent insertion of subdural cup catheter for monitoring of intracranial pressure. A progress computed tomography scan of the brain revealed tension pneumocephalus. As far as the authors are aware, this is the first reported case of tension pneumocephalus resulting from insertion of a subdural intracranial pressure monitor.

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.

Ventriculostomy-related infections in subarachnoid hemorrhage patients-a retrospective study of incidence, etiology, and antimicrobial therapy

BACKGROUND

This study was performed to investigate the incidence and etiology of ventriculostomy-related infections (VRIs) in patients with subarachnoid hemorrhage (SAH) and to assess adherence to local clinical guidelines regarding empirical antimicrobial therapy and diagnostic routines.

METHODS

A total of 191 consecutive SAH patients treated in the neuro-intensive care unit of Uppsala University Hospital between 2010 and 2013 were included retrospectively. Information regarding cerebrospinal fluid samples, bacterial cultures, ventriculostomy treatment, patient characteristics, and antibiotic treatment were collected from electronic patient records.

RESULTS

Eleven patients developed VRI, resulting in an incidence of 5.8% per patient, 5.4% per ventriculostomy catheter, and 4.1 per 1000 catheter days. Coagulase-negative staphylococci caused nine cases of VRI and Klebsiella pneumoniae and Staphylococcus aureus caused one each. Empirical VRI therapy was initiated on 97 occasions in 81 subjects (42.4%). Out of the 11 patients with VRI, four did not receive empirical antibiotic therapy before the positive culture result. The clinical actions performed after analysis of CSF samples were in line with the action suggested by the local guidelines in 307 out of 592 cases (51.9%).

CONCLUSIONS

The incidence of VRI in our cohort was comparable to what has previously been reported. Coagulase-negative staphylococci was the most common agent. Our study demonstrates the difficulty in diagnosing VRI in SAH patients. Improved adherence to clinical guidelines could to some extent reduce the use of empirical antibiotic treatment, but better diagnostic methods and routines are needed.

Pharmacokinetics and Pharmacodynamics of Tissue Plasminogen Activator Administered Through an External Ventricular Drain

BACKGROUND

Intraventricular hemorrhage (IVH) frequently complicates spontaneous intracerebral or subarachnoid hemorrhage (SAH). Administration of intraventricular tissue plasminogen activator (TPA) accelerates blood clearance, but optimal dosing has not been clarified. Using a standardized TPA dose, we assessed peak cerebrospinal fluid (CSF) TPA concentrations, the rate at which TPA clears, and the relationship between TPA concentration and biological activity.

METHODS

Twelve patients with aneurysmal SAH and IVH, treated with endovascular coiling and ventricular drainage, were randomized to receive either 2 mg intraventricular TPA or placebo every 12 h (five doses). CT scans were performed 12, 48, and 72 h after initial administration, and blood was quantified using the SAH Sum and IVH Scores. CSF TPA and fibrin degradation product (D-dimer) concentrations were measured at baseline and 1, 6, and 12 h after the first dose using ELISA assays.

RESULTS

Median CSF TPA concentrations in seven TPA-treated patients were 525 (IQR 352-2129), 323 (233-413), and 47 (29-283) ng/ml, respectively, at 1, 6, and 12 h after drug administration. Peak concentrations varied markedly (401-8398 ng/ml). Two patients still had slightly elevated levels (283-285 ng/ml) when the second dose was due after 12 h. There was no significant correlation between the magnitude of CSF TPA elevation and the rate of blood clearance or degree of D-dimer elevation. D-dimer peaked at 6 h, had declined by 12 h, and correlated strongly with radiographic IVH clearance (r = 0.82, p = 0.02).

CONCLUSIONS

The pharmacokinetics of intraventricular TPA administration varies between individual patients. TPA dose does not need to exceed 2 mg. The optimal administration interval is every 8-12 h.

Hydrogel-coated ventricular catheters for high-risk patients receiving ventricular peritoneum shunt

Shunt infection is a morbid complication of cerebrospinal fluid (CSF) shunting. The catheters with a hydrophilic surface may impede bacterial adherence and thereby reduce catheter-related CSF infection.A retrospective study compared the occurrence of CSF infection related to use of either standard silastic catheters or hydrogel-coated ventricular catheters (Bioglide, Medtronic). The enrolment was available to neurosurgery patients undergoing shunt surgery from October 2012 to 2015 in two centers. The follow-up period was more than months.A total of 78 patients were included in the study. In 33 patients 35-cm hydrogel-coated ventricular peritoneum shunts (VPS) were used, and in remaining 45 patients 35-cm standard silastic VPS catheters were used. Infection occurred in 14 (17.9%) patients, including definite VPS-related CSF infection in 6 patients (7.7%) and probable infection in remaining 8 patients (10.3%). There was a significant difference found in patients with total infection between the two groups [RR (95% CI); 0.200 (0.050-0.803), P = 0.014]. Analysis of Kaplan-Meier curve estimates indicated significant statistical difference between the two catheter types in duration (log rank = 4.204, P < 0.05). Significant statistical differences were also found in the subgroups including previous CSF infection within 1 month (log rank = 4.391, P = 0.04), conversion of external ventricular drains to shunt (Log Rank = 4.520, P = 0.03), and hospital stay >1 month (log rank = 5.252, P = 0.02). There was no difference found between the two groups of the patients with other infections within 1 month. The follow-up period was of 36 months.The hydrogel-coated catheter is a safe and related to lower infection rates for high-risk patients who underwent shunt surgery.

Indicators of external ventricular drainage-related infections--a retrospective observational study

BACKGROUND

External ventricular drainage (EVD) is frequently used in different groups of patients in neurocritical care. Despite the frequent use of EVD, no consensus regarding the diagnosis of EVD-related infection currently exists, and diagnosis is commonly based on criteria for the diagnosis of non-EVD-related CNS infections. This study evaluates the diagnostic accuracy of clinical and laboratory parameters for the prediction of EVD-related infection in patients with proven EVD-related infection.

METHODS

In two tertiary care centers, data on EVD insertions were matched with a microbiologic database of cultured microorganisms and positive Gram stains of cerebrospinal fluid (CSF) to identify patients with EVD-related infections. Available clinical data and results of blood tests and CSF analysis were retrospectively collected. Predefined potential clinical and laboratory predictors of EVD-related infection were compared between three time points: at the time EVD insertion and 48 h before and at the time of occurrence of EVD-related infection.

RESULTS

Thirty-nine patients with EVD-associated infection defined by positive CSF culture or positive CSF Gram stains and concomitant clinical signs of infection were identified. At the time of infection, a significantly higher incidence of abnormal temperature, high respiratory rate, and a slightly but significantly higher incidence of decreased mental state were observed. The assessed blood and CSF parameters did not significantly differ between the different assessment time points.

CONCLUSIONS

Our analysis of 39 patients with culture positive EVD-related infection showed that commonly used clinical and laboratory parameters are not reliable infection predictors.

Validation of a New Noninvasive Intracranial Pressure Monitoring Method by Direct Comparison with an Invasive Technique

The search for a completely noninvasive intracranial pressure (ICPni) monitoring technique capable of real-time digitalized monitoring is the Holy Grail of brain research. If available, it may facilitate many fundamental questions within the range of ample applications in neurosurgery, neurosciences and translational medicine, from pharmaceutical clinical trials, exercise physiology, and space applications. In this work we compare invasive measurements with noninvasive measurements obtained using the proposed new noninvasive method. Saline was infused into the spinal channel of seven rats to produce ICP changes and the simultaneous acquisition of both methods was performed. The similarity in the invasive and noninvasive methods of ICP monitoring was calculated using Pearson's correlation coefficients (r). Good agreement between measures < r > = 0.8 ± 0.2 with a range 0.28-0.96 was shown.

Risk factors associated with infections and need for permanent cerebrospinal fluid diversion in pediatric intensive care patients with externalized ventricular drains

BACKGROUND

Externalized ventricular drains (EVDs) are commonly used in pediatric intensive care units (PICU) but few data are available regarding infection rates, infection risks, or factors associated with conversion to permanent cerebrospinal fluid (CSF) diversion.

METHODS

Retrospective observational study of patients managed with EVDs admitted to a tertiary care PICU from January 2005 to December 2009.

RESULTS

Three hundred eighty patients were identified. Neurologic diagnostic groups were externalization of existing shunt in 196 patients (52 %), brain tumor in 122 patients (32 %), intracranial hemorrhage in 23 patients (6 %), traumatic brain injury in 17 patients (5 %), meningitis in 9 patients (2 %), or other in 13 patients (3 %). Six percent of all patients (24/380) had new infections associated with EVD management for an infection rate of 8.6 per 1,000 catheter days. The median time to positive cultures was 7 days (interquartile range 4.75, 9) after EVD placement. Patients with EVD infections had significantly longer EVD duration 6 versus 11.5 days (p = 0.0001), and higher maximum EVD outputs 1.9 versus 1.5 mL/kg/h (p = 0.0017). Need for permanent CSF diversion was associated with higher maximum EVD drainage (1.3 vs. 1.6 mL/kg/h p < 0.0001), longer EVD duration (5 vs. 4 days, p < 0.005), and younger age (4.5 vs. 8 years, p < 0.02) but not intracranial hypertension (72 vs. 82 % of patients, p = 0.4).

CONCLUSIONS

In our large pediatric cohort, EVD infections were associated with longer EVD duration and higher maximum EVD output. Permanent CSF diversion was more likely in patients with higher maximum EVD drainage, longer EVD duration, and younger age.

Infection Rates in Standard vs. Hydrogel Coated Ventricular Catheters

Background:

Infection related to external ventricular drain (EVD) use is a common neurosurgical complication. Modified catheters with a hydrophilic surface may impede bacterial adherence and thereby reduce catheter related cerebrospinal fluid (CSF) infection.

Methods:

A prospective randomized clinical trial compared the occurrence of CSF infection related to use of either standard silastic or hydrogel coated EVD catheters (Bioglide®, Medtronic). Enrolment was available to all adult neurosurgery patients undergoing placement of a first EVD, at three university centers. The catheters were presoaked in a low concentration of bacitracin solution for 5-10 minutes prior to insertion. Bacterial infection was defined by heavy growth in a single CSF sample or light / medium growth in two consecutive samples. A secondary analysis was also conducted for “probable” CSF infection, including patients started on antibiotics after light / medium growth in a single CSF sample. Statistical analyses included Kaplan-Meier survival curve estimates accompanied by Log Rank and Breslow tests.

Results:

There were 158 randomized patients available to assess for EVD related infection of CSF. The two study groups had similar clinical characteristics including average duration of EVD use (8±4 days). Definite CSF infection occurred in seven and probable infection in another six (8% total). Infection incidence rose steadily from day 2 (1%) to day 11 (11%). There was no difference of daily occurrence of EVD infection between the two catheter types.

Conclusion:

Infection remains a common hazard in the use of EVD, and we found no reduction of infection using the hydrogel-coated catheters when presoaked in low concentration bacitracin solution.

Current concepts of optimal cerebral perfusion pressure in traumatic brain injury

Traumatic brain injury (TBI) consists of varied pathophysiological consequences and alteration of intracranial dynamics, reduction of the cerebral blood flow and oxygenation. In the past decade more emphasis has been directed towards optimizing cerebral perfusion pressure (CPP) in patients who have suffered TBI. Injured brain may show signs of ischemia if CPP remains below 50 mmHg and raising the CPP above 60 mmHg may avoid cerebral oxygen desaturation. Though CPP above 70 mmHg is influential in achieving an improved patient outcome, maintenance of CPP higher than 70 mmHg was associated with greater risk of acute respiratory distress syndrome (ARDS). The target CPP has been laid within 50-70 mmHg. Cerebral blood flow and metabolism are heterogeneous after TBI and with regional temporal differences in the requirement for CPP. Brain monitoring techniques such as jugular venous oximetry, monitoring of brain tissue oxygen tension (PbrO₂), and cerebral microdialysis provide complementary and specific information that permits the selection of the optimal CPP. This review highlights the rationale for use CPP directed therapies and neuromonitoring to identify optimal CPP of head injured patients. The article also reviews the evidence provided by various clinical trials regarding optimal CPP and their application in the management of head injured patients.

Monoblock external ventricular drainage system in the treatment of patients with acute hydrocephalus: a pilot study

Background

Infection is a major complication in patients undergoing external ventricular drainage (EVD). Our study aimed to evaluate the incidence of infection in a series with the monoblock EVD system.

Material/Methods

46 patients treated with EVD at our emergency department were analyzed prospectively to research the incidence of infections with a new EVD system.

Results

The average rate of infection was 8.7%. When we stratified the patients according to the exclusive use of EVD without craniotomies, we identified a reduction in the overall incidence of ventriculitis from 8.7% to 2.3%. Age, etiology, and the presence of ventricular bleeding were not statistically significant risk factors.

Conclusions

Despite the small sample examined in this study, we believe that the monoblock system is a simple, inexpensive device that reduces accidental disconnection of the system.

Long subcutaneous tunnelling reduces infection rates in paediatric external ventricular drains

PURPOSE

The aim of this study is to report the efficacy of long subcutaneous tunnelling of external ventricular drains in reducing rates of infection and catheter displacement in a paediatric population.

METHODS

In children requiring external ventricular drainage, a long-tunnelled drain was placed and managed according to a locally agreed guideline. End points were novel CSF infection incurred during the time of drainage and re-operation to re-site displaced catheters. Data were compared to other published series.

RESULTS

One hundred eighty-one long-tunnelled external ventricular drains (LTEVDs) were inserted. The mean age was 6.6 years (range 0-15.5 years). Reasons for insertion included intraventricular haemorrhage (47 %), infection (27 %), tumour-related hydrocephalus (7.2 %), as a temporising measure (17 %) and trauma (2.2 %). The overall new infection rate for LTEVD was 2.76 %. If the 48 cases where LTEVDs were inserted to treat an existing infection are excluded, the infection rate was 3.8 % (5/133). The mean duration of insertion was 10 days (range 0-42 days). Four LTEVDs (2.2 %) were inadvertently dislodged, requiring reinsertion. Thirteen patients required removal of EVD alone. There was a significant difference (p < 0.05) when comparing our infection rate to 14 publications of infection rates in short-tunnelled EVDs; however, there was no difference when comparing our data to three publications using LTEVDs.

CONCLUSION

The use of an antibiotic-impregnated LTEVD, managed according to a predefined guideline, is associated with significantly reduced infection and displacement rates when compared with contemporary series. It is suggested that this reduction is of both clinical and economic benefits.

Propionibacterium acnes: an underestimated pathogen in implant-associated infections

The role of Propionibacterium acnes in acne and in a wide range of inflammatory diseases is well established. However, P. acnes is also responsible for infections involving implants. Prolonged aerobic and anaerobic agar cultures for 14 days and broth cultures increase the detection rate. In this paper, we review the pathogenic role of P. acnes in implant-associated infections such as prosthetic joints, cardiac devices, breast implants, intraocular lenses, neurosurgical devices, and spine implants. The management of severe infections caused by P. acnes involves a combination of antimicrobial and surgical treatment (often removal of the device). Intravenous penicillin G and ceftriaxone are the first choice for serious infections, with vancomycin and daptomycin as alternatives, and amoxicillin, rifampicin, clindamycin, tetracycline, and levofloxacin for oral treatment. Sonication of explanted prosthetic material improves the diagnosis of implant-associated infections. Molecular methods may further increase the sensitivity of P. acnes detection. Coating of implants with antimicrobial substances could avoid or limit colonization of the surface and thereby reduce the risk of biofilm formation during severe infections. Our understanding of the role of P. acnes in human diseases will likely continue to increase as new associations and pathogenic mechanisms are discovered.

Infection rates of external ventricular drains are reduced by the use of silver-impregnated catheters

BACKGROUND

External ventricular drainage (EVD) placement for temporary cerebrospinal fluid (CSF) diversion is a frequent therapeutic procedure. Several types of EVD catheters are currently available, some of which have an antibacterial effect. This study compares the rates of CSF infections in patients with different types of EVD catheters.

METHODS

This is a retrospective study of 403 patients with a total of 529 implanted EVDs. We analyze the occurrence of EVD-associated infections, microbiological diagnosis, type of EVD catheter (plain polyurethane vs. silver-impregnated), duration of CSF diversion, primary disease, and outcome.

RESULTS

There were a total of 29 patients with EVD infections in the whole study group (7.1 %). A pathogen was detected in all cases. Coagulase-negative staphylococci were detected most frequently (20 out of 29 cases, 70 %). The rate of infections by catheter type was 7.6 % (11 of 145) and 13.8 % (4 out of 29) for two different types of non-coated polyurethane catheters. Silver-impregnated polyurethane catheters became infected in 6.1 % (14 out of 228). The differences between non-coated and silver-coated catheters were statistically significant.

CONCLUSIONS

This study provides comparative data on EVD infections with regard to the type of catheter. Silver-impregnated catheters showed significantly lower infection rates when compared to non-impregnated catheters. The results are critically discussed and compared with the published literature.

Decreasing ventricular infections through the use of a ventriculostomy placement bundle: experience at a single institution

Object

Ventricular infection after ventriculostomy placement carries a high mortality rate. Responding to ventriculostomy infection rates, a multidisciplinary performance improvement team was formed, a comprehensive protocol for ventriculostomy placement was developed, and the efficacy was evaluated.

Methods

A best-practice protocol was developed, including hand hygiene before the procedure; prophylactic antibiotics; sterile gloves changed between preparation, draping, and procedure; hair removal by clipping for dressing adherence; skin preparation using iodine povacrylex (0.7% available iodine) and isopropyl alcohol (74%); full body and head drape; full surgical attire for the surgeon and other bedside providers; and an antimicrobial-impregnated catheter. A checklist of critical components was used to confirm proper insertion and to monitor practice. Procedure-specific infection rates were calculated using the number of infections divided by the number of patients in whom an external ventricular drainage (EVD) device was inserted × 100 (%). Data were reported back to providers and to the committee. Bundle compliance was monitored over a 4-year period.

Results

At the authors' institution, 2928 ventriculostomies were performed between the beginning of the fourth quarter of 2006 and the end of the first quarter of 2012. Although the best-evidence bundle was applied to all patients, only 588 (20.1%) were checklist monitored (increasing from 7% to 23% over the study period). The infection rate for the 2 quarters before bundle implementation was 9.2%. During the study period, the rate decreased quarterly to 2.6% and then to 0%. Over a 4-year period, the rate was 1.06% (2007), 0.66% (2008), 0.15% (2009), and 0.34% (2010); it was 0% in 2011 and the first quarter of 2012. The overall EVD infection rate was 0.46% after bundle implementation.

Conclusions

Bundle implementation including an antimicrobial-impregnated catheter dramatically decreased EVD-related infections. Training and situational awareness of appropriate practice, assisted by the checklist, plus use of the antibiotic-impregnated catheter resulted in sustained reduction in ventriculitis.

Reducing ventriculostomy-related infections to near zero: the eliminating ventriculostomy infection study

Implementation of a standard protocol and use of antibiotic-coated ventricular catheters helped reduce EVD-related infections from 9.2% to almost zero at the University of Florida. This project demonstrated the success of creating a task force to identify areas of improvement, implement solutions, and monitor the outcomes.

Epidural intracranial pressure measurement in rats using a fiber-optic pressure transducer

Elevated intracranial pressure (ICP) is a significant problem in several forms of ischemic brain injury including stroke, traumatic brain injury and cardiac arrest. This elevation may result in further neurological injury, in the form of transtentorial herniation(1,2,3,4), midbrain compression, neurological deficit or increased cerebral infarct(2,4). Current therapies are often inadequate to control elevated ICP in the clinical setting(5,6,7). Thus there is a need for accurate methods of ICP measurement in animal models to further our understanding of the basic mechanisms and to develop new treatments for elevated ICP. In both the clinical and experimental setting ICP cannot be estimated without direct measurement. Several methods of ICP catheter insertion currently exist. Of these the intraventricular catheter has become the clinical 'gold standard' of ICP measurement in humans(8). This method involves the partial removal of skull and the instrumentation of the catheter through brain tissue. Consequently, intraventricular catheters have an infection rate of 6-11%(9). For this reason, subdural and epidural cannulations have become the preferred methods in animal models of ischemic injury. Various ICP measurement techniques have been adapted for animal models, and of these, fluid-filled telemetry catheters(10) and solid state catheters are the most frequently used(11,12,13,14,15). The fluid-filled systems are prone to developing air bubbles in the line, resulting in false ICP readings. Solid state probes avoid this problem (Figure 1). An additional problem is fitting catheters under the skull or into the ventricles without causing any brain injury that might alter the experimental outcomes. Therefore, we have developed a method that places an ICP catheter contiguous with the epidural space, but avoids the need to insert it between skull and brain. An optic fibre pressure catheter (420LP, SAMBA Sensors, Sweden) was used to measure ICP at the epidural location because the location of the pressure sensor (at the very tip of the catheter) was found to produce a high fidelity ICP signal in this model. There are other manufacturers of similar optic fibre technologies(13) that may be used with our methodology. Alternative solid state catheters, which have the pressure sensor located at the side of the catheter tip, would not be appropriate for this model as the signal would be dampened by the presence of the monitoring screw. Here, we present a relatively simple and accurate method to measure ICP. This method can be used across a wide range of ICP related animal models.

Impact of antibiotic-impregnated catheters on the timing of cerebrospinal fluid infections in non-traumatic subarachnoid hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) has been recognized as a risk factor for ventriculostomy-related infections (VRI). In addition to the hemorrhagic cerebrospinal fluid (CSF), the potential need for prolonged catheterization may contribute to the increased CSF infection rate in this population. The use of antibiotic-impregnated catheters (AIC) has effectively reduced the risk of VRI. Herein, we examined specifically the impact of systematic insertion of AIC on the timing of CSF infections in SAH patients.

METHODS

Retrospective review of patients admitted between April 2006 to March 2009 with a non-traumatic SAH who required an external ventriculostomy. Only patients with AIC were included. A meningitis or ventriculitis was diagnosed according to the published criteria of the Center for Disease Control and Prevention.

RESULTS

This study includes 75 patients in which 97 drains were inserted. Seven infections (7/75 = 9.3%) occurred over 1,024 drainage days (DD), resulting in a rate of 6.8 infections/1,000 DD. The mean drainage time was 15.4 days in the infected AIC group compared with 10.2 days in the non-infected AIC group. No infection occurred before day 9 of drainage and 71% (5/7) occurred after more than 2 weeks of drainage. The observed timing of infections is delayed in comparison with that reported in series using non-AIC, which typically occur prior to the 10th day of drainage.

CONCLUSIONS

In the high-risk population of non-traumatic SAH, the use of AIC delays the occurrence of infection compared with that reported with non-antibiotic-impregnated catheters. This may orient management strategies in SAH patients requiring a ventriculostomy.

Comparison of Infection Rate With the Use of Antibiotic-Impregnated vs Standard Extraventricular Drainage Devices

BACKGROUND:

External ventricular drainage (EVD) catheters provide reliable and accurate means of monitoring intracranial pressure and alleviating elevated pressures via drainage of cerebrospinal fluid (CSF). CSF infections occur in approximately 9% of patients. Antibiotic-impregnated (AI) EVD catheters were developed with the goal of reducing the occurrence of EVD catheter-related CSF infections and their associated complications.

OBJECTIVE:

To present an international, prospective, randomized, open-label trial to evaluate infection incidence of AI vs standard EVD catheters.

METHODS:

Infection was defined as (1) proven infection, positive CSF culture and positive Gram stain or (2) suspected infection: (A) positive CSF culture with no organisms identified on initial Gram stain; (B) negative CSF culture with a gram-positive or -negative stain; (C) CSF leukocytosis with a white blood cell/red blood cell count &gt;0.02.

RESULTS:

Four hundred thirty-four patients underwent implantation of an EVD catheter. One hundred seventy-six patients in the AI-EVD cohort and 181 in the standard EVD catheter cohort were eligible for evaluation of infection. The 2 groups were similar in all clinical characteristics. Proven infection was documented in 9 (2.5%) patients (AI: 4 [2.3%] vs standard: 5 [2.8%], P = 1.0). Suspected infection was documented in 31 (17.6%) patients receiving AI and 37 (20.4%) patients receiving standard EVD catheters, P = .504. Duration of time to suspected infection was prolonged in the AI cohort (8.8 ± 6.1 days) compared with the standard EVD cohort (4.6 ± 4.2 days), P = .002.

CONCLUSION:

AI-EVD catheters were associated with an extremely low rate of catheter-related infections. AI catheters were not associated with risk reduction in EVD infection compared to standard catheters. Use of AI-EVD catheters is a safe option for a wide variety of patients requiring CSF drainage and monitoring, but the efficacy of AI-EVD catheters was not supported in this trial.