Duration of intracranial pressure monitoring does not predict daily risk of infectious complications

Escalation therapy in severe traumatic brain injury: how long is intracranial pressure monitoring necessary?

Traumatic brain injury frequently causes an elevation of intracranial pressure (ICP) that could lead to reduction of cerebral perfusion pressure and cause brain ischemia. Invasive ICP monitoring is recommended by international guidelines, in order to reduce the incidence of secondary brain injury; although rare, the complications related to ICP probes could be dependent on the duration of monitoring. The aim of this manuscript is to clarify the appropriate timing for removal and management of invasive ICP monitoring, in order to reduce the risk of related complications and guarantee adequate cerebral autoregulatory control. There is no universal consensus concerning the duration of invasive ICP monitoring and its related complications, although the pertinent literature seems to show that the longer is the monitoring maintenance, the higher is the risk of technical issues. Besides, upon 72 h of normal ICP values or less than 72 h if the first computed tomography scan is normal (none or minimal signs of injury) and the neurological exam is available (allowing to observe variations and possible occurrence of new-onset pathological response), the removal of invasive ICP monitoring can be justified. The availability of non-invasive monitoring systems should be considered to follow up patients' clinical course after invasive ICP probe removal or for substituting the invasive monitoring in case of contraindication to its placement. Recently, optic nerve sheath diameter and straight sinus systolic flow velocity evaluation through ultrasound methods showed a good correlation with ICP values, demonstrating their potential role in place of invasive monitoring or in the early weaning phase from the invasive ICP monitoring.

Escalate and De-Escalate Therapies for Intracranial Pressure Control in Traumatic Brain Injury

Severe traumatic brain injury (TBI) is frequently associated with an elevation of intracranial pressure (ICP), followed by cerebral perfusion pressure (CPP) reduction. Invasive monitoring of ICP is recommended to guide a step-by-step “staircase approach” which aims to normalize ICP values and reduce the risks of secondary damage. However, if such monitoring is not available clinical examination and radiological criteria should be used. A major concern is how to taper the therapies employed for ICP control. The aim of this manuscript is to review the criteria for escalating and withdrawing therapies in TBI patients. Each step of the staircase approach carries a risk of adverse effects related to the duration of treatment. Tapering of barbiturates should start once ICP control has been achieved for at least 24 h, although a period of 2–12 days is often required. Administration of hyperosmolar fluids should be avoided if ICP is normal. Sedation should be reduced after at least 24 h of controlled ICP to allow neurological examination. Removal of invasive ICP monitoring is suggested after 72 h of normal ICP. For patients who have undergone surgical decompression, cranioplasty represents the final step, and an earlier cranioplasty (15–90 days after decompression) seems to reduce the rate of infection, seizures, and hydrocephalus.

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.

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.

A cost effectiveness based safety and efficacy study of resterilized intra-parenchymal catheter based intracranial pressure monitoring in developing world

Background:

The management of traumatic brain injury (TBI) aims to maintain the normal cerebral perfusion in spite of the mass lesions that may occur (haematoma, contusion, and oedema). The monitoring of the intracranial pressure (ICP) is a step in that direction. The intra-parenchymal catheters have the lowest incidence of infection compared to intra-ventricular/subdural catheters with reliable and accurate pressure recordings. The major disadvantage of the intra-parenchymal catheters is the cost, especially in developing nations.

Hypothesis:

Resterilized intra-parenchymal strain gauge catheters can be used safely for ICP monitoring without any added risk of meningitis. The reusage of catheters can bring down the costs. Resterilized catheters/equipment have been approved for usage in cardiac usage, but such study on ICP catheters has not been carried out so far in any part of the world.

Methodology:

A total of 100 consecutive cases of severe TBI receiving ICP monitoring at a level 1 trauma center of a developing nation were prospectively studied (34 cases had fresh catheters, and 66 had resterilized [using ethylene oxide] catheters).

Observations:

The use of reused resterilized catheters was not associated with increased incidence of meningitis or fever (the surrogate marker for infection in this study). Also, there was concordance between the pressure recording of reused catheters and operative finding/subsequent computed tomography scans. These catheters after sterilization could be reused 2–4 times and reliably recorded the ICP (insignificant drift) with no increase in the incidence of meningitis.

Conclusions:

Usage of resterilized intra-parenchymal ICP catheters is feasible, safe, efficacious, and cost effective and brings down the cost of monitoring significantly.

Role of external ventricular drainage in the management of intraventricular hemorrhage; its complications and management

Background:

External ventricular drainage (EVD) is the procedure of choice for the treatment of acute hydrocephalus and increased intracranial pressure in patients of subarachnoid hemorrhage (SAH) and intracerebral hemorrhage with hydrocephalus and its sequelae. We evaluated the use of EVD in patients of SAHs (spontaneous/posttraumatic with/without hydrocephalus), hypertensive intracerebral bleeds with interventricular extensions, along with evaluation of the frequency of occurrence of complications of the procedure, infectious and noninfectious, and their management.

Methods:

During the period of 2½ years, between September 2012 and February 2015, 130 patients were subjected to external drainage procedure and were prospectively enrolled in this study. Information was collected on each patient regarding age, sex, diagnosis, underlying illness, secondary complications, other coexisting infections, use of systemic steroids, antibiotic treatment (systemic and intraventricular), and whether any other neurosurgical procedures were performed within 2 weeks of EVD insertion or any time the duration of ventriculostomy.

Results:

The study population of 130 patients underwent a total of 193 ventriculostomies. Thirty-six patients had ventriculostomy infection (27.6%). Evaluation of the use of EVD was done by comparing preoperative and postoperative grading scores. Forty-nine patients survived and improved their score from Grade 3–5 to Grade 2–4. Twenty-nine patients were moderately disable, 16 were severely disable, and 5 were left in the vegetative state. Evaluation of outcome of patients revealed that there was an overall mortality of 61 (46.9%) patients both in the acute phase and later. 33 of the 39 patients having Glasgow Coma Score (GCS) 3–5 at the time of EVD insertion expired, as against 20 of the 51 patients in GCS 6–8. Patients in GCS 9–12 had an even better outcome, with 8 of the 35 patients in this group expiring.

Conclusions:

The use of EVD should be undertaken only in situation where it is absolutely necessary and ventriculostomy should be kept only for the duration required, and this should be monitored on a daily basis, given the exponential increase in infection after 5 days.

From the Skin to the Brain: Pathophysiology of Colonization and Infection of External Ventricular Drain, a Prospective Observational Study

Ventriculostomy-related infection (VRI) is a serious complication of external ventricular drain (EVD) but its natural history is poorly studied. We prospectively tracked the bacteria pathways from skin towards ventricles to identify the infectious process resulting in ventriculostomy-related colonization (VRC), and VRI. We systematically sampled cerebrospinal fluid (CSF) on a daily basis and collected swabs from both the skin and stopcock every 3.0 days for microbiological analysis including in 101 neurosurgical patient. Risk factors for positive event defined as either VRC or VRI were recorded and related to our microbiological findings. A total of 1261 CSF samples, 473 skin swabs, and 450 stopcock swabs were collected. Skin site was more frequently colonized than stopcock (70 (60%) vs 34 (29%), p = 0.023), and earlier (14 ±1.4 vs 24 ±1.5 days, p<0.0001). Sixty-one (52%) and 32 (27%) skin and stopcock sites were colonized with commensal bacteria, 1 (1%) and 1 (1%) with pathogens, 8 (7%) and 1 (1%) with combined pathogens and commensal bacteria, respectively. Sixteen positive events were diagnosed; a cutaneous origin was identified in 69% of cases. The presence of a pathogen at skin site (6/16 vs 4/85, OR: 11.8, [2.5–56.8], p = 0.002) and CSF leakage (7/16 vs 6/85, OR 10 [2.4–41.2], p = 0.001)) were the two independent significant risk factors statistically linked to positive events occurrence. Our results suggest that VRC and VRI mainly results from an extra-luminal progression of pathogens initially colonizing the skin site where CSF leaks.

A meta-analysis of ventriculostomy-associated cerebrospinal fluid infections

BACKGROUND

Ventriculostomy insertion is a common neurosurgical intervention and can be complicated by ventriculostomy-associated cerebrospinal fluid infection (VAI) which is associated with increased morbidity and mortality. This meta-analysis was aimed at determining the pooled incidence rate (number per 1000 catheter-days) of VAI.

METHODS

Relevant studies were identified from MEDLINE and EMBASE and from reference searching of included studies and recent review articles on relevant topics. The Newcastle-Ottawa Scale was used to assess quality and risk of bias. A random effects model was used to pool individual study estimates and 95% confidence intervals (CI) were calculated using the exact Poisson method. Heterogeneity was assessed using the heterogeneity χ2 and I-squared tests. Subgroup analyses were performed and a funnel plot constructed to assess publication bias.

RESULTS

There were a total of 35 studies which yielded 752 infections from 66,706 catheter-days of observation. The overall pooled incidence rate of VAI was 11.4 per 1000 catheter days (95% CI 9.3 to 13.5), for high quality studies the rate was 10.6 (95% CI 8.3 to 13) and 13.5 (95% CI 8.9 to 18.1) for low quality studies. Studies which had mean duration of EVD treatment of less than 7 days had a pooled VAI rate of 19.6 per 1000 catheter-days, those with mean duration of 7-10 days had VAI rate of 12.8 per 1000 catheter-days and those with mean duration greater than 10 days had VAI rate of 8 per 1000 catheter-days. There was significant heterogeneity for the primary outcome (p = 0.004, I-squared = 44%) and most subgroups. The funnel plot did not show evidence for publication bias.

CONCLUSIONS

The incidence rate of VAI is 11.4 per 1000 catheter-days. Further research should focus on analysis of risk factors for VAI and techniques for reducing the rate of VAI.

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.

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.

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.

External ventricular drain infection: improved technique can reduce infection rates

INTRODUCTION

The placement of external ventricular drain (EVD) is a common neurosurgical procedure to drain cerebrospinal fluid (CSF) in many acute neurosurgical conditions that disrupt the normal CSF absorption pathway. Infection is the primary complication with infection rates ranging between 0% and 45%, and this is associated with significant morbidity and mortality, prolonged hospital stay and increased hospital costs.This article compares and discusses the differences in rates of EVD CSF infection between clinical neurosurgical practice and the infection rates in a group of research patients where EVDs were sampled frequently as part of the study.

MATERIALS AND METHODS

Patients who had EVD placed were identified by review of theatre logs from 2005-2008. A retrospective case-note review was performed with the primary end point being those patients treated with intrathecal antibiotics. Patients within the research group were identified from established data and the same primary endpoint was used. A standard silicone catheter was the EVD used in both cohorts. Patients were excluded if the EVD was placed for diagnoses other than hydrocephalus associated with aneurysmal subarachnoid haemorrhage (SAH).

RESULTS

Ninety-four patients had 156 EVDs placed within the clinical group, 49 patients were treated giving an infection rate within this group of 52.1% per patient and 31.4% per EVD. Thirty-nine patients had 39 EVDs placed within the research group, four patients were treated, the infection rate within this group was 10.3% per EVD, p = 0.0001.

CONCLUSION

Sampling or irrigating ventricular drainage systems does not increase the risk of CNS infection providing the operator has appropriate experience and has used theatre standard aseptic technique.

Malplacement of ventricular catheters by neurosurgeons: a single institution experience

INTRODUCTION

The placement of cerebrospinal fluid (CSF) diversion devices requires an appropriate technical expertise associated with proper surgical training in order to minimize undue complications. This study sought to review a single institution's experience with placement of external ventricular drains (EVD) and ventriculoperitoneal (VP) shunts as performed by neurosurgeons with procedure-specific training.

METHODS

A retrospective database review was conducted for all patients who underwent intraventricular CSF diversion over a 5-year period from March 2003 to February 2008. Included in the analysis were ventriculostomy procedures that included EVDs, VP shunts, and ventriculoatrial shunts.

RESULTS

A total of 138 patients underwent 212 ventriculostomy procedures. Seventy-one (51%) patients were male and sixty-seven (49%) were female. The median age was 50.1 years. A ventriculostomy-related hemorrhage was identified in 15 (7.1%) patients-4 of whom developed new symptoms. Twenty-six (12.3%) ventriculostomy catheters were malplaced as determined from post-procedural imaging. Ventriculostomy-related infections were identified in 7 (3.3%) patients, 4 of whom had EVDs and 3 of whom had VP shunts.

CONCLUSION

The placement of intraventricular catheters by neurosurgeons remains a relatively safe and effective procedure that is associated with infrequent rates of symptomatic hemorrhage and infection.

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.

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.

Central nervous system infections in the neurointensive care unit

Central nervous system (CNS) infections are frequently encountered at the primary care level, in emergency rooms, medical wards, and intensive care units. Advances in immunization techniques and aggressive prevention campaigns have had an impact on the worldwide incidence of community-acquired meningitis, limiting this disease to the adult population. In general, a high index of suspicion is required for the diagnosis, but special attention should be given to the immunocompromised host and post-neurosurgical patient in whom the clinical presentation may be nonspecific. Once the diagnosis is made, broad-spectrum antimicrobials should be administered, followed by diagnostic testing, and targeted antibiotic therapy. Current guidelines for the treatment of meningitis are clinically effective but are not based on randomized, prospective, controlled trials. Despite current therapies, the morbidity of CNS infections is still devastating. Recent trials of the use of corticosteroids as coadjuvants of antibiotic therapy showed promising results and decrease in the morbidity associated with bacterial and tuberculous meningitis. Additional neuroprotective alternatives should be the focus of future research. Similarly, guidelines for the diagnosis and management of post-neurosurgical procedure meningitis and ventriculostomy-related infections are needed.

Continuous antibiotic prophylaxis and cerebral spinal fluid infection in patients with intracranial pressure monitors

INTRODUCTION

Inconsistencies in the recommendation of prophylactic antibiotics for patients with intracranial pressure monitors compelled us to assess the effect of our standard regimen of continuous antibiotic prophylaxis on cerebrospinal fluid infection. We examined the rate, possible risk factors, causative organisms, and characteristics of infection.

METHODS

Three hundred eleven patients admitted between September 1998 and February 2001 with an intracranial pressure monitoring device in place were included. Two hundred eleven patients received a ventriculostomy, 95 an intraparenchymal fiber optic intracranial pressure monitor (ICPM), and 5 both an ICPM and a ventriculostomy.

RESULTS

The overall infection rate was 5.5% (17/311). No patient with an ICPM developed CSF infection. The infection rate among ventriculostomy patients was 8.1% (17/211). The majority of infections (82%) were caused by Gram-positive species. Younger age (OR=1.04 for each year, 95% CI=1.01-1.08, p=0.03) and increasing duration of ventriculostomy insertion (OR=1.2 for each day of catheter insertion, 95% CI=1.1-1.3, p<0.001) were risk factors for CSF infection in multivariate analysis. Infected patients experienced longer lengths of stay in the NICU (p<0.001) and hospital (p<0.001); however, infection did not impact clinical outcome, as measured by mortality and discharge GCS.

CONCLUSION

ICP monitors have a low overall infection rate. When infection occurs, gram positive organisms predominate. For patients with ventriculostomy, duration of catheter insertion strongly predicts infection, but did not alter in-hospital mortality.

A long-term ventricular drainage for patients with germ cell tumors or medulloblastoma

BACKGROUND

Hydrocephalus associated with intracranial germ cell tumors or disseminated medulloblastoma has been treated with ventriculoperitoneal shunt. However, this procedure has a potential risk of intraperitoneal metastasis of these brain tumors. To prevent this potential risk and to minimize the risk of infection, we developed a percutaneous long-tunneled ventricular drainage (PLTVD). To confirm the effectiveness, we retrospectively analyzed the results of this procedure.

METHODS

From 1979 to 2003, we have treated 96 patients with germ cell tumors and medulloblastoma in our hospital. Of 96 patients, 59 (germ cell tumor, 31; medulloblastoma, 28) had hydrocephalus and 13 needed long-term cerebrospinal fluid drainage to manage the obstructive hydrocephalus due to persistent tumor or communicating hydrocephalus due to dissemination. We performed PLTVD for these cases using a flow-controlled shunt device and percutaneous long-tunneled shunt tube (peritoneal catheter) exiting at the upper abdomen and connecting to a closed drainage system. The occurrence of extraneural metastasis and the incidence of infection were evaluated.

RESULTS

The average duration of drainage was 74 days (range, 34-115 days). All 13 cases received full-dose chemotherapy and radiotherapy without infectious complications or extraneural metastasis.

CONCLUSIONS

Percutaneous long-tunneled ventricular drainage was an effective method to manage long-lasting obstructive or communicating hydrocephalus with germ cell tumors and medulloblastoma.

Ventriculostomy-related infections in critically ill patients: a 6-year experience

OBJECT

The authors undertook a study to analyze the risk factors for ventriculostomy-related infections (VRIs) in critically ill patients and their relation with outcome.

METHODS

Demographic, clinical, laboratory, and microbiological data were collected from all 638 consecutive adult patients in whom an external ventriculostomy catheter was placed for monitoring during a 6-year period; patients were treated in a 31-bed intensive care unit (ICU) of a teaching hospital. Of 3726 cerebrospinal fluid (CSF) culture samples analyzed, 1348 (217 patients) showed bacterial growth; of these 97 (obtained in 58 patients [9%]) were considered to represent an infection, 106 (in 68 patients [11%]) colonization, and 145 (in 91 patients [14%]) contamination. Hence, a VRI was diagnosed in 58 (9%) of 638 patients. There were no significant differences in Acute Physiology and Chronic Health Evaluation II score, Glasgow Coma Scale score, and mortality rate, but patients with a VRI stayed longer in the ICU than those without one (p = 0.02). The duration of ventriculostomy monitoring was longer in patients with VRI (median 15 and 9 days, respectively; p = 0.02). Although the daily drained volume of CSF was higher after onset of the infection than before infection in patients with VRI (124 +/- 36 and 85 +/- 14 ml/day, respectively), the need for ventriculoperitoneal shunt placement was no more common in those with VRI than in those without (12 and 15%, respectively; p = 0.2). Multivariate logistic regression revealed that subarachnoid hemorrhage (SAH), intraventricular hemorrhage (IVH), craniotomy, and coinfection were risk factors for VRIs.

CONCLUSIONS

In this large series of patients, VRI was associated with a longer ICU stay, but its presence did not influence survival. A longer duration of ventriculostomy catheter monitoring in patients with VRI might be due to an increased volume of drained CSF during infection. Risk factors associated with VRIs are SAH, IVH, craniotomy, and coinfection.

Ventriculostomy-associated infections: incidence and risk factors

BACKGROUND

The objective of this study was to assess the incidence of ventriculostomy-associated infections (VAI) and to examine the related risk factors.

METHODS

Data on all consecutive patients with ventriculostomy catheters admitted to the intensive care unit (ICU) in a tertiary care center over a 3-year period were identified from the ICU database and from medical records. VAI was documented using a preset definition. The following patient data were documented: demographics, severity of illness measures, indication for the catheter, presence of cerebrospinal fluid (CSF) leak, and length of stay and mortality. The following catheter data were collected: venue of catheter placement (operating room or nonoperating room areas), use of antibiotic irrigation and prophylactic systemic antibiotics, and number of catheter days. The frequency of CSF sampling was documented.

RESULTS

In 84 patients, 99 catheters were placed, of which 19% developed VAI. There was a total of 586 catheter days (infection rate, 32 per 1000 catheter days). The risk of VAI increased steadily until catheter day 7 then reached a plateau. Among patients' factors, repeat catheter insertion was associated with a significant increase in VAI. There were no significant associations with age, severity of illness, indication for the catheter, craniatomy, or presence of CSF leak. Among catheter factors, the number of catheter days and repeat catheter insertion emerged as significant independent predictors on multivariate analysis. Placement outside the operating room was associated with a trend toward higher VAI. The use of prophylactic antibiotic or antibiotic irrigation did not significantly alter VAI rates. Routine surveillance cultures of CSF were no more likely to detect infection than cultures obtained when clinically indicated. Gram-negative bacilli were responsible for 50% of the infections, followed by gram-positive cocci (29%) and others (21%).

CONCLUSIONS

The risk of VAI increases with increasing duration of catheterization and with repeated insertions. The use of local antibiotic irrigation or systemic antibiotics does not appear to reduce the risk of VAI. Routine surveillance cultures of CSF were no more likely to detect infection than cultures obtained when clinically indicated. These findings need to be considered in infection control policies addressing this important issue.

Risk factors for surgical site infections in neurosurgery patients with antibiotic prophylaxis

BACKGROUND

This prospective study aimed to determine the spectrum and the main risk factors of surgical site infection (SSI) after neurosurgical procedures in our clinic.

METHODS

Consecutive patients undergoing neurosurgery between November 1, 2001, and November 1, 2002, were recruited for the study. All patients were followed for a minimum of 2 weeks postoperatively and all SSIs were recorded. The complete medical records of each case were reviewed, and data on 14 possible risk factors were extracted. Statistical analyses were performed to identify the risk factors for SSIs.

RESULTS

A total of 31 postoperative SSIs were identified among 503 cases included in the study, with a resulting overall infection rate of 6.2%. The risk of SSI was increased by age (odds ratio [OR], 1.1; 95% confidence interval [CI], 1.0-1.1; P = .039), operation type such as "shunt operations" (OR, 670.4; 95% CI, 2.6-171123.1; P = .021), presence of foreign body (OR, 141.0; 95% CI, 2.5-7925.9; P = .016), presence of diabetes mellitus (OR, 24.3; 95% CI, 2.1-284.9; P = .011), and intracranial pressure monitoring (OR, 4878.9; 95% CI, 23.8-1001229; P = .002). The predominantly isolated microorganisms in patients with SSIs were Staphylococcus aureus (22 [71.0%]), Acinetobacter baumanii (5 [16.1%]), and Staphylococcus epidermidis (4 [12.9%]).

CONCLUSIONS

SSIs remain an important problem in neurosurgery. Identification of the risk factors for SSI will help physicians to improve patient care and may decrease mortality, morbidity, and health care costs of neurosurgery patients.

Emerging medical and surgical management strategies in the evaluation and treatment of intracerebral hemorrhage

Intracerebral hemorrhage (ICH) accounts for approximately 10% of all strokes and causes high morbidity and mortality. Rupture of the small perforating vessels of the cerebral arteries is caused by chronic hypertension, which induces pathologic changes in the small vessels and accounts for most cases of ICH; however, amyloid angiopathy and other secondary causes are being seen more frequently with the increasing age of the population. Recent computed tomographic studies have revealed that ICH is a dynamic process with up to one third of initial hemorrhages expanding within the first several hours of ictus. Secondary injury is believed to result from the development of cerebral edema and the release of specific neurotoxins associated with the breakdown products of hemoglobin. Treatment is primarily supportive. Surgical evacuation is the treatment of choice for patients with neurologic deterioration from infratentorial hematomas. Randomized trials comparing surgical evacuation to medical management have shown no benefit of surgical removal of supratentorial hemorrhages. New strategies focusing on early hemostasis, improved critical care management, and less invasive surgical techniques for clot evacuation are promising to decrease secondary neurologic injury. We review the pathophysiology of ICH, its medical management, and new treatment strategies for improving patient outcome.

Bacterial meningitis caused by the use of ventricular or lumbar cerebrospinal fluid catheters

Object. In the present study the authors compared the incidence and risk factors for external drainage—related bacterial meningitis (ED-BM) by using ventricular and lumbar catheters.

Methods. A cohort of 230 consecutive patients with ED was evaluated. Cerebrospinal fluid samples were obtained daily for microbiological culture, and ED-BM was defined based on culture results in combination with clinical symptoms. The incidence of ED-BM was 7% in lumbar and 15% in ventricular drains. Independent risk factors included site leakage, drain blockage, and most importantly duration of ED. Despite a higher infection rate, ventricular catheters did not have a significant higher risk of infection after correcting for duration of drainage.

Conclusions. Analysis of data in the present study showed that the incidence of ED-associated death is low (0.45%) in patients who do not receive continuous antibiotic prophylaxis during ED.

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.

Advances in ICP monitoring techniques

With the advent of newer devices for measuring intracranial pressure (ICP) and cerebral metabolism, more alternatives continue to rise aiming to control ICP. This manuscript presents a proposed analysis of different ICP monitoring devices in order to make appropriate selection of them in our clinical setting including general and pediatric applications. A systematic review of the literature was made analyzing the technical advances in ICP monitoring. The recent in vitro and in vivo tests as well as mathematical/computer models were reviewed. Practical applications of principles were discussed and compared based on the mode of pressure transformation. A ventricular catheter connected to an external strain gauge transducer or catheter tip pressure transducer device is considered to be the most accurate method of monitoring ICP and enables therapeutic CSF drainage. The significant infections or hemorrhage associated with ICP devices causing patients morbidity are clinically rare and should not deter the decision to monitor ICP. Parenchymal catheter tip pressure transducer devices are advantageous when ventricular ICP cannot be obtained or if there is an obstruction in the fluid couple, though they have the potential for significant measurement differences and drift due to the inability to recalibrate. Subarachnoid or subdural fluid-coupled devices and epidural ICP devices are currently less accurate. With an increasing miniaturization of the transducers, fiberoptic systems have been developed, however, there is a problem of measurement accuracy during the period of patient monitoring and external calibration should be performed frequently to ensure constant accuracy. Ventriculostomies continue to have a pivotal role in ICP control. With a rational understanding of the applications and limitations of the different ICP monitoring devices, the outcome for critically ill neurological patients is optimized.

Efficacy of antimicrobial-impregnated external ventricular drain catheters: a prospective, randomized, controlled trial

OBJECT

Catheter-related infection of the cerebrospinal fluid (CSF) pathways is a potentially life-threatening complication of external ventricular drainage. A major source of infection is bacterial contamination along the external ventricular drain (EVD) catheter track. The authors examined the efficacy of EVD catheters impregnated with minocycline and rifampin in preventing these catheter-related infections.

METHODS

The authors conducted a prospective, randomized clinical trial at six academic medical centers. All hospitalized patients 18 years or older who required placement of an EVD catheter were eligible for inclusion in the study. Patients were randomly assigned to undergo placement of an EVD with a catheter impregnated with minocycline and rifampin or a standard untreated catheter (control group). To assess primary outcome, CSF samples were collected using a sterile technique at the time of catheter insertion, at least every 72 hours while the catheter remained in place, and at the time of catheter removal. At the time of removal, CSF cultures were obtained from the tip and tunneled segments of each catheter by performing semiquantitative roll-plate and quantitative sonication techniques. Of the 306 patients enrolled in the study, data from 288 were included in the final analysis. Eighteen patients were excluded from analysis: 14 because the ventricular catheter was in place less than 24 hours, and four because CSF cultures obtained at the time of catheter insertion were positive for infection. Of these 288 patients, 139 were assigned to the control group and 149 to the treatment group. The two groups were well matched with respect to all clinical characteristics, including patient sex and mean age, indication for catheter placement, and length of time the catheter remained in place. The antibiotic-impregnated catheters were one half as likely to become colonized as the control catheters (17.9 compared with 36.7%, respectively, p < 0.0012). Positive CSF cultures were seven times less frequent in patients with antibiotic-impregnated catheters compared with those in the control group (1.3 compared with 9.4%, respectively, p = 0.002).

CONCLUSIONS

The use of EVD catheters impregnated with minocycline and rifampin can significantly reduce the risk of catheter-related infections.

Enterobacter cloacae ventriculitis successfully treated with cefepime and gentamicin: case report and review of the literature

A 55-year-old woman was found unresponsive and subsequently was diagnosed with a subarachnoid hemorrhage secondary to a right posterior communicating artery aneurysm. The development of hydrocephalus and decreased mental status necessitated placement of an intraventricular catheter; 18 days later she was diagnosed with Enterobacter cloacae ventriculitis. After treatment was begun with intravenous cefepime 2 g every 8 hours and intraventricular gentamicin 5 mg every 24 hours, the catheter was replaced. Cerebrospinal fluid (CSF) and plasma cefepime concentrations and a CSF trough gentamicin concentration were obtained. Intraventricular gentamicin was administered for 6 days and cefepime for 21 days; both clinical and microbiologic resolution of the ventriculitis occurred. The literature reports limited clinical experience with cefepime for the treatment of central nervous system infections in humans. This case report provides clinical evidence to support administration of intravenous cefepime in critically ill adult patients with Enterobacter ventriculitis. Because CSF is easily obtained from patients with intraventricular catheters, strong consideration should be given to monitoring CSF cefepime concentrations in concert with the minimum inhibitory concentration of the offending pathogen to help assure the efficacy of this approach to therapy.

Bedside invasive monitoring techniques in severe brain-injured patients

In patients with severe brain injury, brain edema, elevated intracranial pressure, and cerebral ischemia are accountable for a significant morbidity and mortality. New invasive methods of monitoring attempt to foresee the physiopathological mechanisms responsible for the production of secondary brain injuries. The available methods for monitoring severely brain-injured patients, their potential usefulness, advantages, and disadvantages are reviewed.

Infection related to intracranial pressure monitors in adults: analysis of risk factors and antibiotic prophylaxis

OBJECTIVE

Infection is a complication related to intracranial pressure monitoring devices. The timing, duration, and role of prophylactic antimicrobial agents against intracranial pressure monitor (ICPM) related infection have not previously been well defined. Risk factors and selection, duration, and timing of antibiotic prophylaxis in patients with ICPMs were evaluated.

METHODS

Records of all consecutive patients who underwent ICPM insertion between 1993 and 1996 were reviewed. Patients included were older than 12 years with an ICPM placed for at least 24 hours. Exclusion criteria consisted of ICPM placed before admission or documented CSF infection before or at the time of insertion. Standard criteria were applied to all patients for diagnosis of CSF infection.

RESULTS

A total of 215 patients were included, 16 (7.4%) of whom developed CSF infection. Antibiotic prophylaxis for ICPM placement was administered to 63% of infected and 59% of non-infected patients. Vancomycin (60%) and cefazolin (34%) were used most often. Sixty per cent (6/16) of patients who developed infection and 45% (53/199) of those without CSF infection received their first antibiotic dose within the 2 hours before ICPM insertion. Risk factors for CSF infection included duration of monitoring greater than 5 days (RR 4.0 (1.3-11.9)); presence of ventriculostomy (RR 3.4 (1.0-10.7)); CSF leak (RR 6.3 (1.5-27.4)); concurrent systemic infection (RR 3.4 (1.2-9.5)); or serial ICPM (RR 4.9 (1. 7-13.8)).

CONCLUSIONS

Administration of antibiotics to patients before or at the time of ICPM placement did not decrease the incidence of CSF infection. Patients found to be at greater risk for infection at our institution included duration of ICPM greater than 5 days, use of ventricular catheter, CSF leak, concurrent systemic infection, or serial ICPM.

Camino intracranial pressure monitor: prospective study of accuracy and complications

OBJECTIVES

The fibreoptic device is a type of intracranial pressure monitor which seems to offer certain advantages over conventional monitoring systems. This study was undertaken to analyse the accuracy, drift characteristics, and complications of the Camino fibreoptic device.

METHODS

One hundred and eight Camino intracranial pressure (ICP) devices, in their three modalities, were implanted during 1997. The most frequent indication for monitoring was severe head injury due to road traffic accidents.

RESULTS

Sixty eight probe tips were cultured; 13.2% of the cases had a positive culture without clinical signs of infection, and 2.9% had a positive culture with clinical signs of ventriculitis. The most common isolated pathogen was Staphylococcus epidermidis. All patients were under cephalosporin prophylaxis during monitoring. Haemorrhage rate in patients without coagulation disorders was 2.1% and 15.3% in patients with coagulation abnormalities. Drift characteristics were studied in 56 cases; there was no drifting from the values expected according to the manufacturer's specifications in 34 probes. There was no relation between direction of the drift and duration of placement, nor between drift and time.

CONCLUSIONS

Although the complication and drift rates were similar to those reported elsewhere, there was no correlation between the direction of the drift and long term monitoring despite the fact that some published papers refer to overestimation of values with time with this type of device.

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

BACKGROUND

The role of prophylactic antibiotics (PABs) in preventing infections associated with intracranial pressure (ICP) monitors and external ventricular drains (EVD) is not well defined.

METHODS

This study includes an analysis of published reports and a survey of current practices regarding the use of PABs with ICP monitors and EVDs. A computerized data search and a review of the abstracts from two major national neurosurgical meetings over the past decade yielded 85 related articles. Three independent investigators, blinded to the title, author(s), institution(s), results, and conclusions of the articles used predetermined inclusion criteria to select studies for meta-analysis. Thirty-six responses were returned from 98 questionnaires (37%) mailed to university neurosurgical programs.

RESULTS

Among the articles reviewed, only two studies met the predetermined inclusion criteria for the meta-analysis, and they were of insufficient size to produce statistically significant results. Among the 36 programs that responded to the survey, 26 (72%) used PABs, mainly cephalosporins (46%) and semisynthetic penicillins (38%), with ICP monitors and EVDs. Twenty-two (85%) used one drug, and 4 (15%) used two drugs. Twenty-two (61%) of the total group reported intra-institutional variation in practices among individual staff neurosurgeons. Nineteen (53%) expressed interest in a retrospective study, and 27 (75%) expressed interest in a prospective study on the role of PABs in minor neurosurgical procedures.

CONCLUSION

No consensus regarding the use of PABs with ICP monitors and EVDs is noted. Randomized controlled trials of sufficiently large size with appropriate blinding are needed to address this issue.

Brain eigenfrequency shifting as a sensitive index of cerebral compliance in an experimental model of epidural hematoma in the rabbit: preliminary study

OBJECTIVE

To verify brain eigenfrequency shifting after the occurrence of a lesion producing mass effect into the cranial vault.

DESIGN

Experimental animal study.

SETTING

Laboratory of experimental surgery affiliated with a university critical care department.

SUBJECTS

Six adult male New Zealand white rabbits.

INTERVENTIONS

A Camino ICP monitor was placed in the parenchyma, and a 5-Fr balloon-tipped catheter and accelerometer were placed into the epidural space.

MEASUREMENTS

Before and after the introduction of successive 0.1-mL increments of autologous blood into the balloon, intracranial pressure (ICP) was recorded along with the accelerometer signal obtained during free vibration of the skull triggered by a calibrated hammer. Fast Fourier transformation of the digitized signal provided the eigenfrequency spectrum. The eigenfrequency showing the sharpest decrease after the initial 0.1-mL volume addition was considered as the best frequency, and its variation in response to subsequent 0.1-mL increments represents the brain eigenfrequency shifting.

MAIN RESULTS

Brain eigenfrequency shifting to lower values occurs for small blood volume increments (up to 0.2 mL). When volume addition becomes >0.3 mL, brain eigenfrequency shifting to higher values is exhibited. The decrease in best frequency after the initial introduction of 0.1 mL is statistically significant (p = .003), in a range of volume in which no significant intracranial pressure difference appears. The respective variation of ICP is explained using a quadratic curve. For volumes of 0 to 0.1 mL, the change in ICP is not statistically significant (p = .08).

CONCLUSIONS

Changes of the brain's physical characteristics by mass addition in the cranial vault can be expressed by brain eigenfrequency shifting. The method seems advantageous because it reliably detects mass additions at low levels where no ICP change occurs. Additionally, it provides serial measurements, and it is less invasive than the currently used methods for intracranial compliance.

The critical care nurse's role in preventing secondary brain injury in severe head trauma: achieving the balance

Secondary brain injury is associated with a reduction in cerebral blood flow, oxygenation and perfusion related to hypotension, hypoxemia and raised intracranial pressure. This has been confirmed on autopsy and is associated with a higher mortality rate, as supported by many studies. The primary goal of nursing management in severe head trauma is to maintain adequate cerebral perfusion and improve cerebral blood flow in order to prevent cerebral ischaemia and secondary injury to the brain. This literature review included a Medline and CINAHL search for published and unpublished research, a manual search of recent literature, a citation review of relevant primary and review articles, contact with primary investigators and clinical observation of case studies using the latest cerebral perfusion research technology. Expert critical care nurses were observed and their practice noted as they cared for severely head-injured patients. The majority of the evidence was derived from class II and class III classifications, which provide guidelines and options for practice. Nursing and medical management were found to overlap, with the focus for the nurse being an integrated balance of scientific, technical and humanistic management. The nurse's role is extremely important because the expert nurse cognitively manipulates many variables over a continuum of care and, if such tasks are skillfully and successfully performed, the incidence of secondary brain injury is reduced.

CSF antibiotic prophylaxis for neurosurgical patients with ventriculostomy: a randomised study

The value of prophylactic antibiotics for patients with ventricular catheter for monitoring and CSF drainage is uncertain. 228 patients were randomised to receive perioperative antibiotics only (Unasyn, Group I) or prolonged antibiotics for the presence of the ventricular catheter (Unasyn and Aztreonam, Group II). The incidence of intracranial and extracranial infection was documented prospectively. Group II patients had a significantly reduced incidence of CSF infection [3/115 (3%) vs 12/113 (11%), p = 0.01] and extracranial infections [23/115 (20%) vs 48/113 (42%), p = 0.002]. CSF pathogens in Group II patients were MRSA and Candida, whereas in Group I, Staphylococci, E coli and Klebsiella. Although prolonged antibiotic prophylaxis significantly reduced the incidence of serious CSF infection as well as extracranial infections, this policy did select resistant or opportunistic pathogens such as Candida and MRSA.

Intracranial pressure: current status in monitoring and management

One of the most frequently occurring questions in the neurological critical care of children involves the indications for measurement of intracranial pressure (ICP) and the appropriate therapies for abnormally elevated ICP. Advances in monitoring technology have improved the safety and accuracy of ICP measurement. Clinical and basic research into the mechanisms of brain swelling and the efficacy of various therapies, especially in the realm of traumatic brain injury, has allowed the development of rational and specific treatment strategies for elevated ICP. For several diseases, the ability to measure and manage ICP has resulted in marked improvements in outcomes. This article reviews the indications for, and recommended methods of, measuring ICP in children and discusses the status of therapies commonly used to control elevated ICP.

Magnitude and prevention of nosocomial infections in the intensive care unit

Nosocomial infections among intensive care unit (ICU) patients usually are related to the use of invasive devices (e.g., mechanical ventilators, urinary catheters, or central venous catheters). This article discusses the impact of these devices and other risk factors for nosocomial infection in ICU patients. Data on etiologic pathogens and device-related infection rates from the National Nosocomial Infection Surveillance System are presented, general infection control guidelines for ICUs are reviewed, and special infection control problems encountered in ICUs are discussed.

Ventriculostomy infections: the effect of monitoring duration and catheter exchange in 584 patients

The investigators undertook a retrospective analysis of ventriculostomy infections to evaluate their relationship to monitoring duration and prophylactic catheter exchange. In 1984, the results of an epidemiological study of ventriculostomy-related infection were published. One of the conclusions of the paper was that the incidence of ventriculostomy-related infections rose after 5 days of monitoring. This led to the recommendation that catheters be prophylactically changed at 5-day intervals if prolonged monitoring was required. A recent randomized prospective study on central venous catheters showed no reduction in infection with prophylactic catheter exchanges. This has led the authors to reexamine their experience with ventriculostomy infections. Data on 584 severely head injured patients with ventriculostomies were prospectively collected in two data banks, The Traumatic Coma Data Bank and The Medical College of Virginia Neurocore Data Bank. These data were retrospectively analyzed for factors associated with ventriculostomy related infections. It was found that there is a relationship of ventriculitis to monitoring duration but it is not simple or linear. There is a rising risk of infection over the first 10 days, but infection then becomes very unlikely despite a population that continues to be at risk. Patients in whom catheters were replaced prior to 5 days did not have a lower infection rate than those whose catheters were exchanged at more than 5-day intervals. Based on these data, it is recommended that ventriculostomy catheters for intracranial pressure monitoring be removed as quickly as possible, and in circumstances in which prolonged monitoring is required, there appears to be no benefit from catheter exchange.