Prophylactic antibiotics with intracranial pressure monitors and external ventricular drains: a review of the evidence

A Bibliometric Analysis of the Top 50 Most Influential Articles on External Ventricular Drains

OBJECTIVE

External ventricular drains (EVDs) are commonly used to remove cerebrospinal fluid and monitor intracranial pressure in patients with neurological dysfunction. Often the first invasive procedure learned in training, ventricular drain placement is the quintessential neurosurgical procedure. This bibliometric analysis highlights the top contributing EVD articles in current evidence-based practice.

METHODS

The Scopus database was used to perform a title-specific, keyword-based search for all publications until September 2022. The keywords "external ventricular drain" or "EVD" or "external ventriculostomy" were used. The 50 most cited articles were selected for analysis. Parameters included the following: title, citation count, citations per year, authors, specialty of first author, institution, country of origin, publishing journal, Source Normalized Impact per Paper, and Hirsch index.

RESULTS

The keyword-based search showed that 8464 articles on EVDs were published between 1991 and 2022. The top 50 articles were published between 1999 and 2019. The top 50 articles acquired a total of 3343 citations with an average of 66.86 citations per paper. The rate of self-citations accounted for an average of 5.16% of the total number of citations. A majority of the top 50 articles focused on EVD infection and placement accuracy. The first and second most cited papers were authored by Zabramski et al and Fried et al, respectively.

CONCLUSIONS

The bibliometric analysis provides a quantitative overview of how topics and interventions are analyzed in academic medicine. In the present study, we evaluated the global trends in EVDs by analyzing the top 50 most cited papers.

From Henry Shrapnel (1761–1842) to today’s neurosurgery: how antipersonnel weapons have laid the foundation of clinical and surgical management of head injury fractures and penetrating brain injuries

Henry Shrapnel invented an antipersonnel weapon capable of defragmenting with the explosion of charge. Modern grenades or improvised explosive devices may be seen as an evolution of Shrapnel’s ammunition. Starting by analyzing the ballistics of these weapons, it is possible to understand the historical evolution of the management of skull fractures and penetrating brain injuries (PBIs).

A circular crack line with a splinter at the center, depressed in bone, was a characteristic feature of fractures due to Shrapnel’s bullet. Three longitudinal fissures, one medial and two lateral, may be present due to tangential blows. Craniectomy and/or fracture reduction were almost always necessary in these cases.

The first document describing medical examination and therapeutic strategies for head-injured patients dates back to 1600 bc (the Edwin Smith Papyrus). Several doctors from the past century, such as Puppe, Matson, and Cushing, proposed different theories about skull fractures and the management of craniocerebral injuries, paving the way for diagnosing and treating these injuries.

Shrapnel fractures required wider craniotomies and in the past surgeons had to deal with more severe injuries. Based on past military experiences during what could be called the postshrapnel age, guidelines for the management of PBIs were introduced in 2001. In these guidelines various concepts were reviewed, such as the importance of antibiotics and seizure prevention; included as well were prognostic factors such as hypotension, coagulopathy, respiratory distress, and Glasgow Coma Scale score. Furthermore, they highlight how it has not been possible to reach a common viewpoint on surgical management. Nevertheless, in contrast with the past, it is preferable to be less aggressive regarding retained fragments if there is no intracranial mass effect.

Although military situations were useful in building basic principles for PBI guidelines, civilian PBIs differ noticeably from military ones. Therefore, there is a need to review modern guidelines in order to apply them in every situation.

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.

Risk of Resistant Organisms and Clostridium difficile with Prolonged Systemic Antibiotic Prophylaxis for Central Nervous System Devices

BACKGROUND

Prolonged systemic antibiotic prophylaxis for central nervous system (CNS) devices may be associated with increased risk of antimicrobial resistance. The primary objective of this study was to determine the impact of prolonged CNS device antibiotic prophylaxis on the growth of resistant microorganisms and Clostridium difficile.

METHODS

This retrospective, observational, cohort study included patients admitted to intensive care units with traumatic brain injury or other neurocritical illness. Patients who received a CNS device and antibiotic prophylaxis for at least 72 h were compared to patients with similar neurologic injuries who did not receive a CNS device.

RESULTS

Study (n = 116) and control (n = 557) patients had mean APACHE II scores of 17.7 ± 9.2 and 15.1 ± 10.6 (p = 0.004) with 53.4 and 24.6 % receiving craniotomies (p < 0.001), respectively. Mean CNS device duration was 9.9 days, and 73 % of patients received cefuroxime for prophylaxis. The study cohort had a higher absolute incidence of resistant organisms compared with the control cohort (15.5 vs 4.1 %; odds ratio 1.93, 95 % CI 0.93-4.03, p = 0.078), though the study was underpowered to show statistical significance in multivariate analysis. C. difficile incidence was similar between groups (2.6 vs 2.0 %; odds ratio 1.45, 95 % CI 0.35-6.12, p = 0.61).

CONCLUSION

We found a higher incidence of resistant organisms in patients receiving prolonged antibiotic prophylaxis with a CNS device, but similar incidence of C. difficile compared to controls. Lack of data supporting prolonged antibiotic prophylaxis for CNS devices and the risk of nosocomial infections with resistant organisms encourage limiting prophylactic antibiotics to a short periprocedural course.

Subdural Empyema in the Setting of Multimodal Intracranial Monitoring

BACKGROUND

Multimodal intracranial monitoring is becoming an increasingly common tool in the management of patients with traumatic brain injury. Although numerous reports detailing the benefits of such advanced monitoring exist in the literature, there is minimal discussion of the possible complications that may arise in this patient population.

CASE DESCRIPTION

We report the case of a 32-year-old patient who had been assaulted and presented initially at an outside facility with a Glasgow Coma Scale score of 8. After transfer to our hospital, his Glasgow Coma Scale score was noted at 7T and multimodal monitoring with the Integra Licox brain tissue oxygen monitor and the Hemedex Bowman perfusion monitor was implemented, along with an external ventricular drain when a standard intracranial pressure monitor indicated increasing intracranial pressure. The patient's intracranial pressure normalized but he did require a course of antibiotics during this time for a fever and methicillin-resistant Staphylococcus aureus. The patient subsequently developed multifocal subdural empyemas requiring surgical evacuation. Postoperatively, the patient's intraoperative cultures remained without bacterial growth, likely related to the 2-week broad-spectrum antibiotic use.

CONCLUSIONS

To our knowledge, this is the first reported incidence of a subdural empyema developing in this setting. Although the safety profile of multimodal intracranial modeling is excellent, with increasing numbers of invasive bedside procedures, neurosurgeons must remain acutely vigilant for the development of infectious complications.

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.

A novel single twist-drill access device for multimodal intracranial monitoring: a 5-year single-institution experience

BACKGROUND

Multimodal intracranial monitoring in the neurosurgical patient requires insertion of probes through multiple craniostomies.

OBJECTIVE

To report our 5-year experience with a novel device allowing multimodal monitoring though a single twist-drill hole.

METHODS

All devices (Hummingbird Synergy, Innerspace) were placed at the Kocher point between 2008 and 2013 at our institution. An independent clinical research nurse prospectively collected data on all bedside placements. Placement accuracy was graded on computed tomography scan as grade 1 (ipsilateral frontal horn or third ventricle), grade 2 (contralateral lateral ventricle), and grade 3 (anywhere else). Infection was monitored with serial cerebrospinal fluid samples.

RESULTS

Two hundred seventy-five devices (198 at bedside, 77 in operating room) were placed in patients with spontaneous subarachnoid hemorrhage (49%), traumatic brain injury (47%), and others (4%) for a median duration of 6 days. A junior (postgraduate year 1-2), midlevel (postgraduate year 3-4), or senior resident (postgraduate year 5-6) placed 39%, 32%, and 29% of the devices, respectively. Ninety-two percent of all devices placed were draining cerebrospinal fluid, ie, were grade 1 (75%) or 2 (17%). Placement accuracy did not vary with level of training. Complications included hemorrhage (10%) and infection (4%), with 1 patient requiring intraparenchymal hematoma evacuation and a second requiring abscess drainage. These rates were lower than reported in the literature for standard external ventricular drains.

CONCLUSION

Hummingbird Synergy is a novel single-port access device for multimodal intracranial monitoring that can be placed safely at the bedside or in the operating room with placement accuracy and has a complication profile similar to or better than that for standard external ventricular drains.

Cerebrospinal fluid and plasma cytokines after subarachnoid haemorrhage: CSF interleukin-6 may be an early marker of infection

BACKGROUND

Cytokines and cytokine receptor concentrations increase in plasma and cerebrospinal fluid (CSF) of patients following subarachnoid haemorrhage (SAH). The relationship between plasma and CSF cytokines, and factors affecting this, are not clear.

METHODS

To help define the relationship, paired plasma and cerebrospinal fluid (CSF) samples were collected from patients subject to ventriculostomy. Concentrations of key inflammatory cytokines, interleukin (IL)-1ß, IL-1 receptor antagonist (IL-1Ra), IL-1 receptor 2, IL-6, IL-8, IL-10, tumour necrosis factor (TNF)-α, and TNF receptors (TNF-R) 1 and 2 were determined by immunoassay of CSF and plasma from 21 patients, where samples were available at three or more time points.

RESULTS

Plasma concentrations of IL-1ß, IL-1Ra, IL-10, TNF-α and TNF-R1 were similar to those in CSF. Plasma TNF-R2 and IL-1R2 concentrations were higher than in CSF. Concentrations of IL-8 and IL-6 in CSF were approximately10 to 1,000-fold higher than in plasma. There was a weak correlation between CSF and plasma IL-8 concentrations (r = 0.26), but no correlation for IL-6. Differences between the central and peripheral pattern of IL-6 were associated with episodes of ventriculostomy-related infection (VRI). A VRI was associated with CSF IL-6 >10,000 pg/mL (P = 0.0002), although peripheral infection was not significantly associated with plasma IL-6.

CONCLUSIONS

These data suggest that plasma cytokine concentrations cannot be used to identify relative changes in the CSF, but that measurement of CSF IL-6 could provide a useful marker of VRI.

Intensive care unit management of aneurysmal subarachnoid hemorrhage

The emergence of dedicated neurologic-neurosurgical intensive care units, advancements in endovascular therapies, and aggressive brain resuscitation and monitoring have contributed to overall improved outcomes for patients with aneurysmal subarachnoid hemorrhage (aSAH) over the past 20 to 30 years. Still, this feared neurologic emergency is associated with substantial mortality and morbidity. Emergency care for patients with aSAH focuses on stabilization, treatment of the aneurysm, controlling intracranial hypertension to optimize cerebral perfusion, and limiting secondary brain injury. This complex disorder can be associated with many neurologic complications such as acute hydrocephalus, rebleeding, global cerebral edema, seizures, vasospasm, and delayed cerebral ischemia in addition to systemic complications such as electrolyte imbalances, cardiopulmonary injury, and infections. Background routine intensive care practices such as avoidance of hyperthermia, venous thromboembolism prophylaxis, and avoidance of severe blood glucose derangements are additional important elements of care.

Intraparenchymal vs extracranial ventricular drain intracranial pressure monitors in traumatic brain injury: less is more?

BACKGROUND

Management of severe traumatic brain injury has centered on continuous intracranial pressure (ICP) monitoring with intraparenchymal ICP monitors (IPM) or extracranial ventricular drains (EVD). Our hypothesis was that neurologic outcomes are unaffected by the type of ICP monitoring device.

STUDY DESIGN

We reviewed 377 adult patients with traumatic brain injury requiring ICP monitoring. Primary outcome was Glasgow Outcome Score (GOS) 1 month after injury. Secondary outcomes included mortality, monitoring-related complications, and length of ICU and hospital stay.

RESULTS

There were 253 patients managed with an IPM and 124 with an EVD. There was no difference in Glasgow Outcome Score (2.7 ± 1.3 vs 2.5 ± 1.3, p = 0.45), mortality (30.9% vs 32.2%, p = 0.82), and hospital length of stay (LOS) (15.6 ± 12.4 days vs 16.4 ± 10.7 days, p = 0.57). Device-related complications (11.9% vs 31.1%, p < 0.001), duration of ICP monitoring (3.8 ± 2.6 days vs 7.3 ± 5.6 days, p < 0.001), and ICU LOS (7.6 ± 5.6 days vs 9.5 ± 6.2 days, p = 0.004) were longer in the EVD group. Age, opening ICP, and size of midline shift were independent predictors for neurologic outcomes and mortality, when type and severity of brain injury, as well as overall injury severity were controlled for. Duration of ICP monitoring and opening ICP were independent predictors for hospital LOS and the former predicted prolonged ICU stay. Device-related complications were affected by type of device.

CONCLUSIONS

Use of EVDs in adult traumatic brain injury patients is associated with prolonged ICP monitoring, ICU LOS, and more frequent device-related complications.

Is the use of antibiotic-impregnated external ventricular drainage beneficial in the management of iatrogenic ventriculitis?

BACKGROUND

Profound evidence substantiates significantly reduced risk of catheter-related infections with prophylactic use of rifampin- and clindamycin-impregnated silicone catheters (Bactiseal(®), Codman Johnson & Johnson, Raynham, MA, USA) for external ventricular drainage (EVD). However, whether Bactiseal(®)-EVD (B-EVD) influences the treatment of EVD-related ventriculitis remains controversial.

METHODS

We performed a retrospective analysis of patients who developed ventriculitis after EVD or ventriculoperitoneal (VP) shunt placement and consequently underwent either placement of B-EVD (group 1) or a standard non-antibiotic-impregnated EVD (group 2). Analyzed parameters included demographic and clinical data, hospitalization time, time until remission of the infection parameters, detection of new bacterial resistance on antibiograms, and clinical outcome in terms of the modified Rankin scale (mRS).

RESULTS

Time until remission of cerebrospinal fluid (CSF) pleocytosis was significantly longer in patients undergoing B-EVD (8 ± 3.8 days; n = 15; group 1) than in patients who underwent standard EVD (5.1 ± 1.8 days; n = 10; group 2). There was no significant difference between both groups for the time until polymorphonuclear cells dropped below 50% of peak value (5.8 ± 1.6 vs. 4.1 ± 2.9 days), CRP dropped below 10 mg/l (4.2 ± 3.5 vs. 5.6 ± 3.3 days), the time of plasma neutrophil remission (5.7 ± 2.6 vs. 5.3 ± 3.2 days) and hospitalization time (28 ± 12.5 vs. 35 ± 19.4 days). The mRS for both groups was 2. Development of new antibiotic resistance did not occur in either group.

CONCLUSIONS

This retrospective pilot study indicates that B-EVD might have no major advantage in the management of EVD or VP-shunt-related ventriculitis. Based on published reports and the results of this study, data support only the prophylactic use of B-EVD for prevention of EVD-related infections. Prospective randomized clinical trials are warranted to further evaluate the role of B-EVD in the treatment of ventriculitis.

Intracerebral Abscess Associated With the Camino Intracranial Pressure Monitor: Case Report and Review of the Literature

BACKGROUND AND IMPORTANCE:

Intracranial pressure (ICP) monitoring is a mainstay in the management of traumatic brain injury. Large investigations have validated the safety and efficacy of ICP monitors in comatose patients. Clinically relevant infections are extremely rare and cerebral abscess has never been reported with the Camino device. We describe an exceptional case of a life-threatening intracerebral abscess from an intraparenchymal ICP monitor.

CLINICAL PRESENTATION:

A 35-month-old child required 7 days of ICP monitoring after a fall from a 2-story window. His hospital course was complicated by severe airway edema treated, in part, with high-dose corticosteroid therapy for a total of 10 days. Two weeks later, the patient deteriorated acutely owing to a large intracerebral abscess under the previous ICP monitor site. Urgent craniotomy with evacuation of the abscess was performed on 2 separate occasions. Cultures grew methicillin-sensitive Staphylococcus aureus, which was treated with long-term antibiotics. At the 3-month follow-up, the patient was meeting age-appropriate milestones without focal deficits.

CONCLUSION:

To the best of our knowledge, this is the first report describing an intracerebral abscess as a complication from an intraparenchymal pressure monitor. Corticosteroid therapy may have constituted an independent risk factor for the ICP monitor--associated infection, as well as reinsertion of the ICP monitoring device at the same site. That this is the first reported parenchymal infectious complication underscores the safety of this device with respect to infection. When reinsertion of a parenchymal monitor is considered, a new site should be chosen.

Maintained deep brain stimulation for severe dystonia despite infection by using externalized electrodes and an extracorporeal pulse generator

Infection in the context of implant surgery is a dreaded complication, usually necessitating the removal of all affected hardware. Severe dystonia is a debilitating condition that can present as an emergency and can occasionally be life threatening. The authors present 2 cases of severe dystonia in which deep brain stimulation was maintained despite the presence of infection, using ongoing stimulation by externalization of electrode wires and an extracorporeal pulse generator. This allowed the infection to clear and wounds to heal while maintaining stimulation. This strategy is similar to that used in the management of infected cardiac pacemakers. The authors suggest that this prolonged extracorporeal stimulation should be considered by neurosurgeons in the face of this difficult clinical situation.

Contemporary pharmacologic issues in the management of traumatic brain injury

Traumatic brain injury (TBI) is a major cause of death and disability in the United States. While there are no pharmacotherapeutic options currently available for attenuating the neurologic injury cascade after TBI, numerous pharmacologic issues are encountered in these critically ill patients. Adequate fluid resuscitation, reversal of coagulopathy, maintenance of cerebral perfusion, and treatment of intracranial hypertension are common interventions early in the treatment of TBI. Other deleterious complications such as venous thromboembolism, extremes in glucose concentrations, and stress-related mucosal disease should be anticipated and avoided. Early provision of nutrition and prevention of drug or alcohol withdrawal are also cornerstones of routine care in TBI patients. Prevention of infections and seizures may also be helpful. Clinicians caring for TBI patients should be familiar with the pharmacologic issues typical of this vulnerable population in order to develop optimal strategies of care to anticipate and prevent common complications.

A bundle approach to reduce the incidence of external ventricular and lumbar drain-related infections

Object

An important complication of external CSF drainage is bacterial meningitis or ventriculitis, resulting in increased morbidity, mortality, and health care costs. In 2003, a high rate (37%) of probable drain-related infections was identified at the authors' hospital. A multidisciplinary working group was installed to reduce this incidence to < 10% within 1.5 years.

Methods

An intervention strategy based on 5 pillars (increased awareness, focused standard operating procedures, a diagnostic and therapeutic algorithm, timely administration of prophylaxis, and improvement of the drainage system) was designed and implemented from 2004 to 2006. During this period all patients with external CSF drainage were prospectively monitored.

Results

Between 2004 and 2006, there were 467 patients in whom 579 drains (external ventricular and external lumbar) had been placed. The overall incidence of drain-related infections was 16.2% in 2004, 8.9% in 2005, and 11.3% in 2006. For external lumbar drains the number of infections per 100 drain days was 2.4 in 2004, 0.6 in 2005, and 0.8 in 2006. For external ventricular drains these rates were 1.7, 1.0, and 1.2, respectively. Meanwhile, the causative noncutaneous microorganisms, indicative for systemic-contamination during manipulation, decreased. By retrospective analysis, the proportion of patients with a probable drain-related infection decreased from 37% in 2003 to 9% in 2005 and 2006.

Conclusions

The authors' multidisciplinary approach in which different preventive measures were combined was associated with a significant reduction in the incidence of drain-related secondary meningitis, and thus provides an important improvement of patient safety.

Risk factors and complications of intracranial pressure monitoring with a fiberoptic device

We prospectively investigated the complications associated with intraparenchymal intracranial pressure (ICP) monitoring using the Camino intracranial pressure device. A fiberoptic ICP monitoring transducer was implanted in 631 patients. About half of the patients (n=303) also received an external ventricular drainage set (EVDS). The durations (mean+/-SD) of ICP monitoring in patients without and with an EVDS were 6.5+/-4.4 and 7.3+/-5.1 days, respectively. Infection occurred in 6 patients with only an ICP transducer (6/328, 1.8%) and 24 patients with an EVDS also (24/303, 7.9%). The duration of monitoring had no effect on infection, whereas the use of an EVDS for more than 9 days increased infection risk by 5.11 times. Other complications included transducer disconnection (2.37%), epidural hematoma (0.47%), contusion (0.47%), defective probe (0.31%), broken transducer (0.31%), dislocation of the fixation screw (0.15%), and intraparenchymal hematoma (0.15%). In conclusion, intraparenchymal ICP monitoring systems can be safely used in patients who either have, or are at risk of developing, increased ICP.

Impact of nosocomial infectious complications after subarachnoid hemorrhage

OBJECTIVE

Critically ill neurological patients are susceptible to infections that may be distinct from other intensive care patients. The aim of this study is to quantify the prevalence, risk factors, and effect on the outcome of nosocomial infectious complications in patients with subarachnoid hemorrhage (SAH).

METHODS

We studied 573 consecutive patients with SAH, identified the most prevalent infectious complications, and performed univariate analyses to determine risk factors for each complication. Multiple logistic regression models were constructed to calculate adjusted odds ratios for associated risk factors and to assess the impact of infectious complications on 3-month outcome as evaluated with the modified Rankin Scale.

RESULTS

The most prevalent nosocomial infections were pneumonia (n = 114, 20%), urinary tract infection (n = 77, 13%), bloodstream infection (BSI) (n = 48, 8%), and meningitis/ventriculitis (n = 28, 5%). Significant independent associations with pneumonia included older age, poor Hunt and Hess grade, intubation/mechanical ventilation, and loss of consciousness at ictus. Urinary tract infection was associated with female sex and central line use. BSI was also associated with central line use, and meningitis/ventriculitis was associated with the presence of intraventricular hemorrhage and external ventricular drainage (all P < 0.05). After adjustment for Hunt and Hess grade, aneurysm size, and age, pneumonia (adjusted odds ratio, 2.04; 95% confidence interval, 1.12-3.71; P = 0.020) and BSI (adjusted odds ratio, 2.51; 95% confidence interval, 1.14-5.56; P = 0.023) independently predicted death or severe disability at 3 months. Prolonged length of stay was significantly associated with all infection types (P < 0.001).

CONCLUSION

Pneumonia and BSI are common infectious complications of SAH and independently predict poor outcome. The implementation of infection-control measures may be needed to improve outcome after SAH.

Pharmacologic options for CNS infections caused by resistant Gram-positive organisms

Infectious disease continues to evolve, presenting new and challenging clinical situations for practitioners. Specific to device-related and neurosurgical-related CNS infections, Gram-positive organisms are of growing concern. Current Infection Disease Society of America guidelines for the treatment of CNS infections offer little direction after conventional therapy, consisting of vancomycin, has failed or the patient has demonstrated intolerance. A review of literature evaluating alternative therapies, specifically linezolid, quinupristin/dalfopristin, daptomycin and tigecycline, will be presented. Interpretations of these data are offered followed by a brief presentation of future therapies, including ortavancin, telavancin, dalbavancin, ceftobiprole and iclaprim, all of which possess potent Gram-positive activity.

SURGICAL SITE INFECTIONS AFTER ELECTIVE NEUROSURGERY

OBJECTIVE

To evaluate the incidence and risk factors of postsurgical site infections (SSIs) in elective neurosurgical procedures in patients treated with an ultrashort antibiotic protocol.

METHODS

In this consecutive series of 1747 patients treated with elective neurosurgery and ultrashort prophylactic antibiotic therapy at the Fondazione Istituto Nazionale Neurologico “Carlo Besta” in Milan, the rate of SSIs was 0.7% (13 patients). When only clean neurosurgery was considered, there were 11 such SSIs (1.52%) in 726 craniotomies and one SSI (0.15) in 663 spinal operations. The antibiotic protocol was prolonged in every case of external communication as cerebrospinal fluid leaks or external drainages.

RESULTS

The infection rate of the whole series was low (0.72%), and a risk factor identified for SSIs in clean neurosurgery was longer surgery duration. The relative risk estimate was 12.6 for surgeries lasting 2 hours and 24.3 for surgeries lasting 3 or more hours. Patients aged older than 50 years had a lower risk of developing SSI with a relative risk of 0.23 when compared with patients aged younger than 50 years.

CONCLUSION

The present series reports a low incidence of SSIs for elective neurosurgery, even for high-risk complex craniotomies performed for tumor removal. Given that an antibiotic protocol prolongation was used to pretreat any early signs of infection and external communication, the protocol was appropriate for the case mix. The two identified risk factors (surgical duration &gt; 2 hours and middle-aged patients [16–50 yr]) may be indicators of other factors, such as the level of surgical complexity and poor neurological outcome.

Risk factors associated with postcraniotomy meningitis

OBJECTIVE

The authors conducted a retrospective cohort study to determine the incidence, bacteriological features, and risk factors for postcraniotomy meningitis.

METHODS

Patients older than 18 years who underwent nonstereotactic craniotomies between January 1996 and March 2000 and who survived for more than 7 days were included. Operations for placement of burr holes and shunts were excluded. Records of the first 30 postoperative days were abstracted. Host factors, types of craniotomy, and pre- and postoperative variables were evaluated as risk factors for meningitis

RESULTS

Among 453 patients, there were 25 cases of meningitis. Eight out of 12 culture-positive cases were the result of gram-positive cocci. Four hundred twenty (92%) patients received antibiotic prophylaxis, most commonly a first-generation cephalosporin. In multivariate analysis, the risk of meningitis was increased by surgery that entered a sinus (odds ratio [OR], 4.49; P = 0.018), an increase in the American Society of Anesthesiologists score (OR, 1.72; P = 0.023), and increases in the number of days of external ventricular drainage (OR, 1.21; P = 0.049) and intracranial pressure monitoring (OR, 1.24; P = 0.002).

CONCLUSION

Access of upper airway bacteria to the surgical wound, host factors as expressed by the American Society of Anesthesiologists score, and duration of device-related postoperative communication of the cerebrospinal fluid and the environment are major risk factors for postoperative meningitis after craniotomy.

Influence of broad-spectrum antibiotic prophylaxis on intracranial pressure monitor infections and subsequent infectious complications in head-injured patients

BACKGROUND

The benefit of antibiotic prophylaxis for intracranial pressure (ICP) monitors remains controversial, and clinical practice varies widely. Whether any antibiotic coverage, particularly broad-spectrum coverage, reduces monitor-related infections remains unproved, and exposure to antibiotics may affect the susceptibility patterns of pathogens producing subsequent infectious complications. Despite the lack of data supporting its use, our level I trauma center had a long-standing ICP monitor prophylaxis protocol that provided broad-spectrum coverage that included ceftriaxone. In April 2002, a protocol change was instituted that substituted cefazolin for ceftriaxone as single-agent prophylaxis for ICP monitors.

HYPOTHESIS

Broader-spectrum antibiotic prophylaxis does not reduce ICP monitor-related infections but is associated with acquisition of more drug-resistant infections than narrow-spectrum prophylaxis.

METHODS

To evaluate the influence of broad- versus narrow-spectrum prophylaxis, a three year period encompassing each practice was selected. All injured patients with ICP monitors placed between January 1, 2001, and December 31, 2003 (n = 279), were identified using the Vanderbilt trauma database. Antibiotic prophylaxis for ICP monitors was determined using the hospital financial database to identify all antibiotics given to individual patients and subsequent chart review to identify those antibiotics given solely for ICP prophylaxis. A total of 119 patients received narrow-spectrum (either cefazolin or vancomycin; n = 100) or no (n = 19) prophylaxis, whereas 160 received broad-spectrum prophylaxis (ceftriaxone or ciprofloxacin). The two groups did not differ with respect to baseline demographics, type of ICP monitor, or duration of monitor placement. Infectious complications were determined by continuous infection surveillance utilizing standard U.S. Centers for Disease Control and Prevention National Nosocomial Infection Surveillance System (CDC-NNIS) definitions and maintained in a contemporary database. The influence of broad-spectrum antibiotic prophylaxis on both ICP monitor infections and subsequent infections outside the central nervous system (CNS) was determined.

RESULTS

Nine patients (3.2%) developed CNS infections; two of 119 patients (1.7%) who received narrow-spectrum or no prophylaxis versus seven of 160 patients (4.4%) who received broad-spectrum prophylaxis (p = NS). Only the duration of monitor placement and Injury Severity Score were associated with the infection rate. In the total population, 185 infections occurred in 93 patients (33%). Infection rates did not differ between patients who received narrow-spectrum or no prophylaxis (32%) and those who received broad-spectrum prophylaxis (34%). However, patients who received broad-spectrum prophylaxis acquired gram-negative infections with significantly greater antibiotic resistance.

CONCLUSIONS

Broad-spectrum antibiotic prophylaxis of ICP monitors does not reduce CNS infections, but is associated with a shift to resistant gram-negative pathogens in subsequent infectious complications. Thus, broad-spectrum antibiotic prophylaxis of ICP monitors should be eliminated or minimized unless data from randomized trials prove its utility.

The Camino intracranial pressure device in clinical practice. Assessment in a 1000 cases

BACKGROUND

Intracranial pressure (ICP) monitoring has become standard in the management of neurocritical patients. A variety of monitoring techniques and devices are available, each offering advantages and disadvantages. Analysis of large populations has never been performed.

PATIENTS AND METHODS

A prospective study was designed to evaluate the Camino fiberoptic intraparenchymal cerebral pressure monitor for complications and accuracy.

RESULTS

Between 1992-2004 one thousand consecutive patients had a fiberoptic ICP monitor placed. The most frequent indication for monitoring was severe head injury (697 cases). The average duration of ICP monitoring was 184.6 +/- 94.3 hours; the range was 16-581 hours. Zero drift (range, -17 to 21 mm Hg; mean 7.3 +/- 5.1) was recorded after the devices were removed from 624 patients. Mechanical complications such as: breakage of the optical fiber (n = 17); dislocations of the fixation screw (n = 15) or the probe (n = 13); and failure of ICP recording for unknown reasons (n = 4) were found in 49 Camino devices.

CONCLUSIONS

The Camino ICP sensor remains one of the most popular ICP monitoring devices for use in critical neurosurgical patients. The system offers reliable ICP measurements in an acceptable percentage of device complications and the advantage of in vivo recalibration. The incidence of technical complications was low and similar to others devices.

Intracranial pressure monitoring: why monitor?

Evidence suggests that the mortality and morbidity of acquired brain injury could be reduced if clinicians used an aggressive intracranial pressure guided approach to care. Despite nearly 50 years of evidence that intracranial pressure monitoring benefits patient care, only about half of the patients who could benefit are monitored. Some clinicians express concerns regarding risks such as bleeding, infections, and inaccuracy of the technology. Others cite cost as the reason. This article discusses the risks and benefits of intracranial pressure monitoring and the current state of evidence of why patients should be monitored.

Intrathecal colistin for treatment of highly resistant Pseudomonas ventriculitis. Case report and review of the literature

Nosocomial infections with organisms resistant to multiple antibiotic agents represent an evolving challenge in the intensive care setting, particularly in patients requiring surgical diversion of cerebrospinal fluid. The authors present the case of a 51-year-old woman who endured protracted hospitalization and required multiple surgeries including placement of a ventriculoperitoneal shunt. The shunt subsequently became colonized with Pseudomonas aeruginosa, which demonstrated intermediate sensitivity to amikacin and full resistance to all other antibiotics tested 'After failing to respond to intravenous imipenem as well as intravenous and intrathecal amikacin, the patient was successfully treated with intravenous and intrathecal colistin. Colistin is a polymyxin-type antibiotic, rarely used outside of topical application because of reported nephrotoxicity associated with parenteral administration. With activity limited to Gram-negative organisms, colistin is bactericidal by directly disrupting the structure of cell membranes. Authors of a few case reports in the literature have described successful treatment of various ventriculitis with the intrathecal administration of colistin. With bacterial resistances outpacing the pharmaceutical industry's ability to develop novel antibiotics, colistin represents an important alternative in situations involving multidrug-resistant organisms.

Prophylactic antibiotics adversely affect nosocomial pneumonia in trauma patients

BACKGROUND

Little data are available regarding the impact that prolonged prophylactic antibiotic use (>48 hours) has on the development of nosocomial pneumonia. This retrospective study was conducted to assess the effect that prolonged prophylactic antibiotic use has on the development of nosocomial pneumonia and antibiotic use complications.

METHODS

The records of patients who contracted nosocomial pneumonia during mechanical ventilation were retrospectively reviewed. These patients then were classified into two groups: those who received prolonged prophylactic antibiotics before the diagnosis of pneumonia and those who did not receive antibiotics.

RESULTS

For the patients who received prolonged prophylactic antibiotics, the first pneumonia was diagnosed later, the causative organisms were more likely to be resistant or Gram-negative bacteria, and the incidence of antibiotic complications were two times greater than for patients who did not receive extended antibiotic prophylaxis.

CONCLUSION

Justification for the use and duration of prolonged (>48 hours) prophylactic antibiotics requires careful reevaluation because this practice is associated with significant clinical complications that lead to increased use of patient resources, lengthened hospital stay, and higher cost.

Nosocomial enterobacter meningitis: risk factors, management, and treatment outcomes

Enterobacter species are increasingly a cause of nosocomial meningitis among neurosurgery patients, but risk factors for these infections are not well defined. A review of all adult patients hospitalized at the University of California-Los Angeles (UCLA) Medical Center during an 8-year period identified 15 postneurosurgical cases of Enterobacter meningitis (EM). Cure was achieved in 14 cases (93%), and efficacy was similar for carbapenem- and cephalosporin-based treatment. A matched case-control study comparing 26 controls with 13 case patients hospitalized exclusively at the UCLA Medical Center found that external cerebrospinal fluid (CSF) drainage devices (odds ratio [OR], 21.8; P=.001), isolation of Enterobacter species from a non-CSF culture (OR, 24.6; P=.002), and prolonged administration of antimicrobial drugs before the diagnosis of meningitis that were inactive in vitro against Enterobacter species (OR, 13.3; P=.008) were independent risk factors for EM. Despite favorable treatment outcomes, EM is a serious infection associated with Enterobacter species colonization or infection at other surgical sites, with selective antimicrobial pressure, and with invasive CNS devices.

Early diagnosis of external ventricular drainage infection: results of a prospective study

OBJECTIVES

The aim of this study was to evaluate the influence of total drainage time on the risk of catheter infection, and the predictive value of standard laboratory examinations for the diagnosis of bacteriologically recorded cerebrospinal fluid (CSF) infection during external ventricular drainage.

METHODS

During a three year period, all patients of the neurosurgical intensive care unit (ICU), who received an external ventricular drain, were prospectivly studied. Daily CSF samples were obtained and examined for cell count, glucose and protein content. Bacteriological cultures were taken three times a week, and serum sepsis parameters were determined.

RESULTS

130 patients received a total of 186 external ventricular drains. The ventricular catheters were in place from one to 25 days (mean 7.1 days). In 1343 days of drainage, the authors recorded 41 positive bacteriological cultures in 21 patients between the first and the 22nd drainage day (mean 6.4). No significant correlation was found between drainage time and positive CSF culture. The only parameter that significantly correlated with the occurrence of a positive CSF culture was the CSF cell count (unpaired t test, p<0.05).

CONCLUSIONS

Drainage time is not a significant risk factor for catheter infection. Increasing CSF cell count should lead to the suspicion of bacteriological drainage contamination. Other standard laboratory parameters, such as peripheral leucocyte count, CSF glucose, CSF protein, or serum sepsis parameters, are not reliable predictors for incipient ventricular catheter infection.

Infection control: avoiding the inevitable

Infection, while a major cause of morbidity, should not be considered an inevitable consequence of injury. Good aseptic technique, compulsive attention to detail, and thorough understanding of the points addressed in the following list of critical points are the best guarantee that infection will not add avoidable morbidity to misfortune. Critical points regarding infectious problems in care of the injured child: 1. Polymicrobial infection is the rule with 50% of isolates being mixed aerobic and anaerobic bacteria. 2. It is a misnomer to consider antibiotic use in a pediatric trauma victim as prophylactic. Antimicrobials used in this setting are best considered adjunctive. 3. The major indication for anti-infective therapy in pediatric trauma is an injury with a high probability of infection. 4. Antibiotics do not sterilize the wound or body cavity; they limit bacterial proliferation, thereby supplementing effective immune control. 5. Available studies suggest that 24 hours is as efficacious as a longer treatment duration in a purely adjunctive mode. 6. In bites inflicted by dogs and cats, Pasturella species are frequent. 7. Human bites may result in infection by Eikenella corrodens. 8. Based on this bacteriology, adjunctive intravenous ampicillin sulbactam or oral amoxicillin clavulanate are recommended for human and animal bites. 9. Tetanus prophylaxis is indicated in all significant soft tissue injuries. 10. Risk of osteomyelitis correlates directly with the extent of the associated soft tissue injury and vascular compromise. 11. The majority of infectious complications in the injured child are not a consequence of the injury itself, but rather in the treatment thereof. 12. In the injured child the most common nosocomial infection is lower respiratory followed by primary blood stream and the urinary tract. 13. The management of nosocomial pneumonia in the injured child is based on the time of diagnoses. Early evidence of pulmonary infection requires treatment with a third generation cephalosporin with or without an antistaphylococcal penicillin. Late pneumonia is treated with an aminoglycoside with or without an antipseudomonal added. 14. Catheter related infection is, in the injured child, overwhelmingly gram positive with coagulase negative staphlococcal species accounting for 30-60% of isolates. Staphlococcus aureus is responsible for an additional 15-20%. 15. The role of antibiotics in the prevention of catheter related meningitis is controversial. Recent adult studies suggest no advantage to their routine use. If utilized, they should only be employed prophylactically and not continued throughout the monitoring period. 16. Lack of response to treatment of sepsis may represent an inappropriate antimicrobial agent, improper dosage, inability to achieve adequate levels at the site of infection. (eg, CSF) fungal pathogen, and/or ongoing contamination or undrained purulent focus.

Neuroinflammation and infection

Brain insults of various forms are always followed by a complex inflammatory reaction or cascade. This cascade has stimulated much research, and may be a target for future therapeutic interventions. During the cascade, both proinflammatory and anti-inflammatory processes are initiated, and tissue and neuronal repair mechanisms are also initiated. It is speculated that, because of the complex nature of the inflammatory reaction and its feedback loops, the future therapeutic manipulations in this area will be complex. Manipulation of inflammation may have beneficial effects in controlling the secondary inflammatory insult, but may be detrimental in blunting the anti-inflammatory and antioxidant responses to this inflammation, thus delaying initiation of tissue repair.