Strategies to Decrease the Risk of Ventricular Catheter Infections: A Review of the Evidence

Significant Reduction in External Ventricular Drain-Related Infections After Introducing a Novel Bundle Protocol: A Before and After Trial

BACKGROUND

External ventricular drain (EVD)-related infection (ERI) is a serious complication in neurosurgical patients. The estimated ERI rates range from 5 to 20 cases per 1,000 EVD catheter days. The pathophysiology of ERI is similar to central line-associated bloodstream infections (CLABSIs) stemming from skin-derived bacterial colonization. The use of bundle management can reduce CLABSI rates. Due to the pathogenic similarities between infections related to the two devices, we developed and evaluated the effectiveness of an ERI-bundle protocol based on CLABSI bundles.

METHODS

From November 2016 to November 2021, we conducted a study to evaluate the effectiveness of an ERI-bundle protocol. This study adopted a before-and-after trial, comparing the ERI rates for the 2 years before and 3 years after the introduction of the newly developed ERI-bundle protocol. We also analyzed the contributing factors to ERI using logistic regression analysis.

RESULTS

A total of 183 patients with 2,381 days of catheter use were analyzed. The ERI rate decreased significantly after the ERI-bundle protocol from 16.7% (14 of 84; 14.35 per 1,000 catheter days) to 4.0% (4 of 99; 3.21 per 1,000 catheter days) (P = 0.004).

CONCLUSION

Introduction of the ERI-bundle protocol was very effective in reducing ERI.

2023 Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage: A Guideline From the American Heart Association/American Stroke Association

AIM

The "2023 Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage" replaces the 2012 "Guidelines for the Management of Aneurysmal Subarachnoid Hemorrhage." The 2023 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with aneurysmal subarachnoid hemorrhage.

METHODS

A comprehensive search for literature published since the 2012 guideline, derived from research principally involving human subjects, published in English, and indexed in MEDLINE, PubMed, Cochrane Library, and other selected databases relevant to this guideline, was conducted between March 2022 and June 2022. In addition, the guideline writing group reviewed documents on related subject matter previously published by the American Heart Association. Newer studies published between July 2022 and November 2022 that affected recommendation content, Class of Recommendation, or Level of Evidence were included if appropriate. Structure: Aneurysmal subarachnoid hemorrhage is a significant global public health threat and a severely morbid and often deadly condition. The 2023 aneurysmal subarachnoid hemorrhage guideline provides recommendations based on current evidence for the treatment of these patients. The recommendations present an evidence-based approach to preventing, diagnosing, and managing patients with aneurysmal subarachnoid hemorrhage, with the intent to improve quality of care and align with patients' and their families' and caregivers' interests. Many recommendations from the previous aneurysmal subarachnoid hemorrhage guidelines have been updated with new evidence, and new recommendations have been created when supported by published data.

Listeria meningitis associated with tonsillar herniation in an immunocompetent school-aged child

Listeria monocytogenes can cause severe illnesses such as gastroenteritis, sepsis and neurolisteriosis, especially in infants, the elderly and immunocompromised patients. We report a case of a previously healthy school-aged girl presenting with severe neurological deficits found to have Listeria meningoencephalitis. Her potential exposure to L. monocytogenes was consumption of contaminated cheese. She had some clinical improvement after initiation of tailored Listeria anti-microbial coverage with ampicillin and gentamicin; however, she developed hydrocephalus requiring external ventricular drain placement and tonsillar herniation requiring emergent posterior fossa decompression. The patient made significant improvements after neurosurgical intervention, and along with continued antibiotics and subsequent rehabilitation services, she improved to near full recovery within a year. The case highlights that neurolisteriosis can affect even immunocompetent children, and aggressive neurosurgical interventions should be considered in patients who develop severe complications such as hydrocephalus and tonsillar herniation to improve outcomes.

An external ventricular drainage catheter impregnated with rifampicin, trimethoprim and triclosan, with extended activity against MDR Gram-negative bacteria: an in vitro and in vivo study

Background

External ventricular drainage (EVD) carries a high risk of ventriculitis, increasingly caused by MDR Gram-negative bacteria such as Escherichia coli and Acinetobacter baumannii. Existing antimicrobial EVD catheters are not effective against these, and we have developed a catheter with activity against MDR bacteria and demonstrated the safety of the new formulation for use in the brain.

Objectives

Our aim was to determine the ability of a newly formulated impregnated EVD catheters to withstand challenge with MDR Gram-negative bacteria and to obtain information about its safety for use in the CNS.

Methods

Catheters impregnated with three antimicrobials (rifampicin, trimethoprim and triclosan) were challenged in flow conditions at four weekly timepoints with high doses of MDR bacteria, including MRSA and Acinetobacter, and monitored for bacterial colonization. Catheter segments were also inserted intracerebrally into Wistar rats, which were monitored for clinical and behavioural change, and weight loss. Brains were removed after either 1 week or 4 weeks, and examined for evidence of inflammation and toxicity.

Results

Control catheters colonized quickly after the first challenge, while no colonization occurred in the impregnated catheters even after the 4 week challenge. Animals receiving the antimicrobial segments behaved normally and gained weight as expected. Neurohistochemistry revealed only surgical trauma and no evidence of neurotoxicity.

Conclusions

The antimicrobial catheter appears to withstand bacterial challenge for at least 4 weeks, suggesting that it might offer protection against infection with MDR Gram-negative bacteria in patients undergoing EVD. It also appears to be safe for use in the CNS.

Ventricular Catheter Tract Hemorrhage as a Risk Factor for Ventriculostomy-Related Infection

BACKGROUND

Ventriculostomy-related infection (VRI) is a feared complication of external ventricular drain (EVD) placement. Although many contributing factors to VRI have been examined, little is known whether there is an association between ventriculostomy-related catheter tract hemorrhage (VCTH) and VRI.

OBJECTIVE

To evaluate risk factors for VRI and assess possible correlations with VCTH.

METHODS

We performed a retrospective analysis of patients with EVD placement in a neurocritical care unit between 2011 and 2015. VRI was defined as clinical signs of infection with a positive cerebrospinal fluid gram stain and isolation of cerebrospinal fluid culture. VCTH was diagnosed by computed tomography immediately after EVD insertion.

RESULTS

A total of 247 patients with EVD were identified during the 5-yr study period. An association between VCTH and gram-negative VRI was identified (P = .02). Ten percent (25 of 247 patients) developed a VRI, and 7% (18 of 247 patients) had a VCTH. Of the 25 patients with VRI, 20% (n = 5) had a VCTH, compared to 6% (n = 13) of 222 patients who had an EVD placed but did not develop VRI. There were no significant differences in demographic and clinical factors except for multiple EVD insertions (P < .00001), EVD duration (P < .001), and hospital length of stay (P < .001).

CONCLUSION

VCTH is a potentially significant risk factor for VRI. Further analysis will be needed to confirm the strength of this association, and to delineate the possible mechanisms by which tract hemorrhage may serve as a nidus for bacterial penetration into the central nervous system.

Prevention of surgical site infections after brain surgery: the prehistoric period to the present

In this historical vignette, the authors discuss the prevention of surgical site infections (SSIs) after brain surgery from the prehistoric period to the present. Although the mechanism for infection was not fully understood until the 19th century, records demonstrate that as early as 10,000 bc, practitioners used gold, a biocidal material, for cranioplasties and attempted to approximate wounds by tying a patient's hair across the incision. Written records from the Egyptian and Babylonian period depict the process of soaking head dressings in alcohol, an antibacterial agent. In the Greek and Early Byzantine period, Hippocrates argued against the formation of pus in wounds and continued to champion the use of wine in wound management. In the 16th century, intracranial silver drains were first utilized in an effort to prevent postoperative infections. The turning point of SSI prevention was in 1867, when Joseph Lister illustrated the connection between Louis Pasteur's discovery of the fermentation process and the suppuration of wounds. Today, there are ongoing investigations and debates about the optimal techniques to prevent SSI after brain surgery. Although tremendous progress in the field of SSI prevention since the prehistoric period has been made, SSI continues to affect morbidity and mortality after brain surgery.

Variations in Strategies to Prevent Ventriculostomy-Related Infections: A Practice Survey

BACKGROUND AND PURPOSE

The ideal strategy to prevent infections in patients with external ventricular drains (EVDs) is unclear.

METHODS

We conducted a cross-sectional survey of members of the Neurocritical Care Society on infection prevention practices for patients with EVDs between April and July 2015.

RESULTS

The survey was completed by 52 individuals (5% response rate). Catheter selection, use of prolonged prophylactic systemic antibiotics (PPSAs), cerebrospinal fluid (CSF) collection policies, location of EVD placement, and performance of routine EVD exchanges varied. Antibiotic-impregnated catheters (AICs) and conventional catheters (CCs) were used with similar frequency, but no respondents reported routine use of silver-impregnated catheters (SICs). The majority of respondents were either neutral or disagreed with the need for PPSA with all catheter types (CC: 75%, AIC: 85%, and SIC: 87%). Despite this, 55% of the respondents reported PPSAs were routinely administered to patients with EVDs at their institutions. The majority (80%) of the respondents reported CSF collection only on an as-needed basis. The EVD placement was restricted to the operating room at 27% of the respondents' institutions. Only 2 respondents (4%) reported that routine EVD exchanges were performed at their institution.

CONCLUSION

Practice patterns demonstrate that institutions use varying strategies to prevent ventriculostomy-related infections. Identification and further study of optimum care for these patients are essential to decrease the risk of complications and to aid development of practice standards.

Ventriculostomies without dressings: Low infection rates but room for quality improvement

Objective

Ventriculostomies are common procedures for patients with severe neurologic insults including trauma, aneurysmal rupture, tumor, infection or following an operation. Infection secondary to a ventriculostomy, meningitis or ventriculitis, carries a high morbidity and mortality. Insertion practices and maintenance of these interventions was evaluated.

Methods

A retrospective review was completed of patients receiving ventriculostomies at a single institution from October 2007 through September 2013. Basic patient demographics, methods of insertion and presence of infection were collected and analyzed.

Results

The mean of age of patients receiving ventriculostomies was 49 years of age and the most common indications for insertion were trauma, infection and nontraumatic intracranial hemorrhage (aneurysmal subarachnoid hemorrhage (SAH), hemorrhagic stroke, arteriovenous malformation (AVM)). External ventricular drains (EVDs) were inserted after minimal hair removal at the time of procedure, tunneling following procedure and securement of EVDs with suture at exit of skin and remainder of drain stapled to scalp without additional dressing applied. The infection rate using this practice was 5.1%.

Conclusion

Ventriculostomies with minimal hair removal and no dressing have equivalent infection rates with the most recent published national average.

Does release of antimicrobial agents from impregnated external ventricular drainage catheters affect the diagnosis of ventriculitis?

OBJECTIVE

Recently concern has arisen over the effect of released antimicrobial agents from antibiotic-impregnated external ventricular drainage (EVD) catheters on the reliability of CSF culture for diagnosis of ventriculitis. The authors designed a laboratory study to investigate this possibility, and to determine whether there was also a risk of loss of bacterial viability when CSF samples were delayed in transport to the laboratory.

METHODS

Three types of commercially available antibiotic-impregnated EVD catheters were perfused with a suspension of bacteria (Staphylococcus epidermidis) over 21 days. Samples were analyzed for bacterial viability and for concentrations of antibiotics released from the catheters. The authors also investigated the effect on bacterial viability in samples stored at 18°C and 4°C to simulate delay in CSF samples reaching the laboratory for analysis.

RESULTS

Bacterial viability was significantly reduced in all 3 catheter types when sampled on Day 1, but this effect was not observed in later samples. The results were reflected in stored samples, with significant loss of viability in Day 1 samples but with little further loss of viable bacteria in samples obtained after this time point. All samples stored for 18 hours showed significant loss of viable bacteria.

CONCLUSIONS

While there were differences between the catheters, only samples taken on Day 1 showed a significant reduction in the numbers of viable bacteria after passing through the catheters. This reduction coincided with higher concentrations of antimicrobial agents in the first few hours after perfusion began. Similarly, bacterial viability declined significantly after storage of Day 1 samples, but only slightly in samples obtained thereafter. The results indicate that drugs released from these antimicrobial catheters are unlikely to affect the diagnosis of ventriculitis, as sampling for this purpose is not usually conducted in the first 24 hours of EVD.

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.

Intracranial pressure monitoring, cerebral perfusion pressure estimation, and ICP/CPP-guided therapy: a standard of care or optional extra after brain injury?

Measurement of intracranial pressure (ICP) and mean arterial pressure (MAP) is used to derive cerebral perfusion pressure (CPP) and to guide targeted therapy of acute brain injury (ABI) during neurointensive care. Here we provide a narrative review of the evidence for ICP monitoring, CPP estimation, and ICP/CPP-guided therapy after ABI. Despite its widespread use, there is currently no class I evidence that ICP/CPP-guided therapy for any cerebral pathology improves outcomes; indeed some evidence suggests that it makes no difference, and some that it may worsen outcomes. Similarly, no class I evidence can currently advise the ideal CPP for any form of ABI. 'Optimal' CPP is likely patient-, time-, and pathology-specific. Further, CPP estimation requires correct referencing (at the level of the foramen of Monro as opposed to the level of the heart) for MAP measurement to avoid CPP over-estimation and adverse patient outcomes. Evidence is emerging for the role of other monitors of cerebral well-being that enable the clinician to employ an individualized multimodality monitoring approach in patients with ABI, and these are briefly reviewed. While acknowledging difficulties in conducting robust prospective randomized studies in this area, such high-quality evidence for the utility of ICP/CPP-directed therapy in ABI is urgently required. So, too, is the wider adoption of multimodality neuromonitoring to guide optimal management of ICP and CPP, and a greater understanding of the underlying pathophysiology of the different forms of ABI and what exactly the different monitoring tools used actually represent.

Central Nervous System Infections

Central nervous system (CNS) infections—i.e., infections involving the brain (cerebrum and cerebellum), spinal cord, optic nerves, and their covering membranes—are medical emergencies that are associated with substantial morbidity, mortality, or long-term sequelae that may have catastrophic implications for the quality of life of affected individuals. Acute CNS infections that warrant neurointensive care (ICU) admission fall broadly into three categories—meningitis, encephalitis, and abscesses—and generally result from blood-borne spread of the respective microorganisms. Other causes of CNS infections include head trauma resulting in fractures at the base of the skull or the cribriform plate that can lead to an opening between the CNS and the sinuses, mastoid, the middle ear, or the nasopharynx. Extrinsic contamination of the CNS can occur intraoperatively during neurosurgical procedures. Also, implanted medical devices or adjunct hardware (e.g., shunts, ventriculostomies, or external drainage tubes) and congenital malformations (e.g., spina bifida or sinus tracts) can become colonized and serve as sources or foci of infection. Viruses, such as rabies, herpes simplex virus, or polioviruses, can spread to the CNS via intraneural pathways resulting in encephalitis. If infection occurs at sites (e.g., middle ear or mastoid) contiguous with the CNS, infection may spread directly into the CNS causing brain abscesses; alternatively, the organism may reach the CNS indirectly via venous drainage or the sheaths of cranial and spinal nerves. Abscesses also may become localized in the subdural or epidural spaces. Meningitis results if bacteria spread directly from an abscess to the subarachnoid space. CNS abscesses may be a result of pyogenic meningitis or from septic emboli associated with endocarditis, lung abscess, or other serious purulent infections. Breaches of the blood–brain barrier (BBB) can result in CNS infections. Causes of such breaches include damage (e.g., microhemorrhage or necrosis of surrounding tissue) to the BBB; mechanical obstruction of microvessels by parasitized red blood cells, leukocytes, or platelets; overproduction of cytokines that degrade tight junction proteins; or microbe-specific interactions with the BBB that facilitate transcellular passage of the microorganism. The microorganisms that cause CNS infections include a wide range of bacteria, mycobacteria, yeasts, fungi, viruses, spirochaetes (e.g., neurosyphilis), and parasites (e.g., cerebral malaria and strongyloidiasis). The clinical picture of the various infections can be nonspecific or characterized by distinct, recognizable clinical syndromes. At some juncture, individuals with severe acute CNS infections require critical care management that warrants neuro-ICU admission. The implications for CNS infections are serious and complex and include the increased human and material resources necessary to manage very sick patients, the difficulties in triaging patients with vague or mild symptoms, and ascertaining the precise cause and degree of CNS involvement at the time of admission to the neuro-ICU. This chapter addresses a wide range of severe CNS infections that are better managed in the neuro-ICU. Topics covered include the medical epidemiology of the respective CNS infection; discussions of the relevant neuroanatomy and blood supply (essential for understanding the pathogenesis of CNS infections) and pathophysiology; symptoms and signs; diagnostic procedures, including essential neuroimaging studies; therapeutic options, including empirical therapy where indicated; and the perennial issue of the utility and effectiveness of steroid therapy for certain CNS infections. Finally, therapeutic options and alternatives are discussed, including the choices of antimicrobial agents best able to cross the BBB, supportive therapy, and prognosis.

A Simple Protocol to Prevent External Ventricular Drain Infections

BACKGROUND:

External ventricular drains (EVDs) are associated with high rates of infection, and EVD infections cause substantial morbidity and mortality.

OBJECTIVE:

To determine whether the introduction of an evidence-based EVD infection control protocol could reduce the rate of EVD infections.

METHODS:

This was a retrospective analysis of an EVD infection control protocol introduced in a tertiary care neurointensive care unit. We compared rates of cerebrospinal fluid culture positivity and ventriculitis for the 3 years before and 3 years after the introduction of an evidence-based EVD infection control protocol. A total of 262 EVD placements were analyzed, with a total of 2499 catheter-days.

RESULTS:

The rate of cerebrospinal fluid culture positivity decreased from 9.8% (14 of 143; 11.43 per 1000 catheter-days) at baseline to 0.8% (1 of 119; 0.79 per 1000 catheter-days) in the EVD infection control protocol period (P = .001). The rate of ventriculitis decreased from 6.3% (9 of 143; 7.35 per 1000 catheter-days) to 0.8% (1 of 119; 0.79 per 1000 catheter-days; P = .02).

CONCLUSION:

The introduction of a simple, evidence-based infection control protocol was associated with a dramatic reduction in the risk of EVD infection.

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.

Multimodal intracranial monitoring: implications for clinical practice

This article presents an overview of intracranial monitoring techniques during the perioperative and intensive care management of neurologic patients. Various regional and global brain monitors are available; some modalities are well established whereas others are new to the clinical arena and their indications are still being evaluated. Indications for monitoring are reviewed, modalities critically evaluated, and future directions identified.