Post-neurosurgical and spontaneous gram-negative bacillary meningitis in adults

Evaluation of Intraventricular/Intrathecal Antimicrobial Therapy in the Treatment of Nosocomial Meningitis Caused by Multidrug-Resistant Gram-Negative Bacteria after Central Nervous System Surgery

Introduction

Postoperative meningitis (POM) is an infection with high mortality and morbidity following central nervous system surgery due to trauma or tumor. Intrathecal/intraventricular (IT/IVT) antibiotic administrations have been considered as the last treatment options for multidrug-resistance (MDR) Gram-negative bacteria that do not respond to intravenous (IV) regimens. IT/IVT can bypass the blood-brain barrier, obtain a more effective antibiotic concentration in CSF, and reduce systemic side effects. We aimed to determine the characteristics of postoperative patients who were diagnosed with MDR POM during follow-up in our intensive care unit (ICU). Material and Methods. In this study, POM patients who were followed up in ICU after the central nervous system intervention between January 2016 and December 2019 and whose MDR Gram-negative bacteria were isolated from CSF were evaluated. As soon as the patients were diagnosed with POM, a catheter was inserted and treatment was started.

Results

Microbiological eradication was achieved in 3 ± 0.8 days with 30 mg/day amikacin treatment in POM due to K. pneumoniae and 3.7 ± 1.95 days with colistin sodium 10 mg/day treatment in POM due to A. baumannii via IT/IVT catheter. IT/IVT treatment was utilized for a median of 10 days and continued until the defined cure criteria were achieved. While cure was achieved in 6 of 14 POM cases, 8 of them were exitus. Discussion and Conclusion. To avoid the severe consequences of postoperative meningitis, acting fast and adding IT/IVT methods to parenteral administration routes by considering the distribution of MDR microorganisms within the hospital while planning effective treatment will increase the clinical success.

Clinical Features of Post-Operative Nosocomial Meningitis in Adults and Evaluation of Efficiency of Intrathecal Treatment

Background: Post-operative nosocomial meningitis is a critical complication that develops in patients after neurosurgical interventions and operations. Patients and Methods: Data were collected for 65 patients who were diagnosed as having nosocomial meningitis after neurosurgery. The agent profile, clinical and biochemical differences in gram-negative and gram-positive meningitis, and the effectiveness of intrathecal antibiotic administration in cases with carbapenem-resistant gram-negative agents were evaluated. Results: Gram-negative bacteria were isolated in 52.3% of patients. In gram-negative cases of post-operative nosocomial meningitis, white blood cell count (p = 0.015), C-reactive protein (p = 0.001), cerebrospinal fluid leukocyte count (p = 0.0001), and protein (p = 0.0001) were higher, and glucose (p = 0.002) was lower. Concurrent bacteremia (p = 0.041), 14-day mortality (p = 0.022), and 30-day mortality (p = 0.023) were higher in gram-negative cases. Empirical treatment was appropriate in 78.5% of the patients. Seventeen patients (26.2%) received intrathecal antibiotic agents in addition to intravenous antibiotic treatment because of carbapenem-resistant gram-negative bacteria. Nine (53%) of the patients receiving intrathecal therapy had Acinetobacter baumannii as the agent, six had Klebsiella pneumoniae (35.4%), one had Pseudomonas aeruginosa (5.8%), and one had Providencia rettgeri (5.8%). The mean intravenous treatment duration was 21.4 ± 10.6 (4-60) days, and the mean intrathecal treatment duration was 17.6 ± 14.0 (1-51) days. Eleven patients received colistimethate sodium intrathecally (1 × 10 mg/d), three patients received amikacin intrathecally (1 × 10 mg/d), and three patients received gentamicin intrathecally (1 × 10 mg/d). Clinical and microbiologic treatment success was achieved in nine patients (53%). Conclusions: In cases of meningitis caused by carbapenem-resistant agents, intrathecal administration of antibiotic agents such as gentamicin, amikacin, and colistin with limited blood-brain barrier transition in intravenous administration will increase survival. Therefore, intrathecal antibiotic administration should be considered as a part of routine of nosocomial meningitis.

Intrathecal and intraventricular antibiotics for postoperative Gram-negative meningitis and ventriculitis

Background:

Postoperative meningitis is a growing cause of concern, especially with the evolution of multidrug-resistant organism. The authors evaluate the use of intraventricular/intrathecal (IVT/IT) antibiotics for postoperative gram-negative meningitis in patients whom intravenous antibiotics were ineffective.

Methods:

Medical records were retrospectively reviewed and neurosurgery patients with gram-negative postoperative infection meningitis/ventriculitis were enrolled in the study. Their demographics, hospital course, and outcomes were recorded in a pro forma and analyzed using Statistical Package for the Social Sciences, version 19.

Results:

The review identified 21 patients with postneurosurgical gram-negative meningitis/ventriculitis who were treated with IVT or IT antibiotics. The most common organism was Acinetobacter species (n = 14; 66%). Amikacin was used in 7 patients, polymyxin B in 9 patients, and colistin in 5 patients. A combination of antibiotics was used in one patient. Cerebrospinal fluid sterility was achieved in all patients with no incidence of relapse. There was a single death, though that was not related to the infectious process as the patient had a massive pulmonary embolism.

Conclusion:

The findings of this study suggest that IVT and IT antibiotic therapy is a useful option in patients who are nonresponsive to standard intravenous therapy with little or no side effects.

The Role of Endoscopic Lavage in Recalcitrant Multidrug-Resistant Gram-Negative Ventriculitis Among Neurosurgical Patients

INTRODUCTION

Ventriculitis is a serious infection associated with high mortality even when both intravenous (IV) and intrathecal (IT) antibiotics are administered. Poor outcome in patients with ventriculitis indicates the need to be more aggressive in our attempts to expeditiously eradicate the infection. The purpose of this study was to evaluate the role of endoscopic lavage (EL) in patients with severe purulent ventriculitis, unresponsive to IV and IT antibiotics.

METHODS

All consecutive patients with severe ventriculitis caused by multidrug-resistant gram-negative bacteria, undergoing EL after failure of prolonged courses of IV and IT antibiotics, were included in the study. The outcome in all these patients was otherwise expected to be uniformly dismal.

RESULTS

There were 5 males and 2 females. The age range was one month to 45 years. All patients had frank intraventricular pus. Acinetobacter baumannii was the most common organism grown in cultures. Two patients had multiple bacterial growth in cerebrospinal fluid cultures. The duration of pre-EL IV/IT antibiotics ranged from 3 to 8 weeks. Microbiological cure was achieved in all (7/7) and clinical cure in 86% of patients (6/7). One patient died despite achieving cerebrospinal fluid sterilization 3 months later as a result of progressive white matter edema.

CONCLUSIONS

The addition of IT antibiotics has resulted in improved outcome in patients with ventriculitis; however, some patients continue to be unresponsive to antibiotics. EL can play a complementary role in eradicating such recalcitrant infections. EL should be considered in any patient with ventriculitis, if infection persists even after ∼7-10 days of IVand IT antibiotics.

Spontaneous Escherichia coli bacterial meningitis mimicking heatstroke in an adult

Bacterial meningitis can be difficult to recognize: the meningeal triad symptoms are not always present and the alteration in mental status can mimic heatstroke. Escherichia coli meningitis is a serious disease whose early diagnosis, appropriate antibiotic treatment, and hemodynamic management are essential.

Impact of round-the-clock CSF Gram stain on empirical therapy for suspected central nervous system infections

The impact of round-the-clock cerebrospinal fluid (CSF) Gram stain on overnight empirical therapy for suspected central nervous system (CNS) infections was investigated. All consecutive overnight CSF Gram stains between 2006 and 2011 were included. The impact of a positive or a negative test on empirical therapy was evaluated and compared to other clinical and biological indications based on institutional guidelines. Bacterial CNS infection was documented in 51/241 suspected cases. Overnight CSF Gram stain was positive in 24/51. Upon validation, there were two false-positive and one false-negative results. The sensitivity and specificity were 41 and 99 %, respectively. All patients but one had other indications for empirical therapy than Gram stain alone. Upon obtaining the Gram result, empirical therapy was modified in 7/24, including the addition of an appropriate agent (1), addition of unnecessary agents (3) and simplification of unnecessary combination therapy (3/11). Among 74 cases with a negative CSF Gram stain and without formal indication for empirical therapy, antibiotics were withheld in only 29. Round-the-clock CSF Gram stain had a low impact on overnight empirical therapy for suspected CNS infections and was associated with several misinterpretation errors. Clinicians showed little confidence in CSF direct examination for simplifying or withholding therapy before definite microbiological results.

Intraventricular and lumbar intrathecal administration of antibiotics in postneurosurgical patients with meningitis and/or ventriculitis in a serious clinical state

Object

To date, reports on the clinical efficacy of intraventricularly and intrathecally administered antibiotics for the treatment of neurosurgical ventriculitis and meningitis in adults are limited. The authors aimed to evaluate the efficacy and safety of the intraventricular (IVT) and lumbar intrathecal (IT) administration of antibiotics in critically ill neurosurgical patients.

Methods

Thirty-four postneurosurgical patients with meningitis and ventriculitis were studied. Intraventricular/lumbar intrathecal antibiotics were administered due to positive CSF cultures persisting despite the use of intravenous antibiotics. The time period until CSF sterilization, changes in clinical state, and efficacy of different routes of antibiotic administration were evaluated.

Results

The mean time necessary to obtain CSF sterilization was 2.9 ± 2.7 days (range 1–12 days). The CSF cultures became negative within 24 hours after the administration of IVT/IT antibiotics in 17 patients (50%) and up to 48 hours in a further 6 patients (18%). The clinical outcome of patients assessed by the modified Rankin Scale improved in 17 patients (50%), stayed unchanged in 10 patients (29%), and was impaired in 1 patient (3%). Six patients (18%) died; however, 2 of them died due to reasons not directly related to meningitis or ventriculitis, so the overall mortality rate for meningitis and/or ventriculitis was 11.8% in this group of patients. All patients with ventriculitis (n = 4) were treated by antibiotics administered via the IVT route. The average time to CSF sterilization was 6.5 days in the patients with ventriculitis. Thirty patients had clinical signs of meningitis without ventriculitis. Despite the higher ratio of unfavorable Gram-negative meningitis in the subgroup of patients treated via lumbar drainage, the mean duration of CSF sterilization was 2.2 days compared with 2.6 days in the subgroup treated via external ventricular drainage, a difference that was not statistically significant (p = 0.3). Adverse effects of IVT/IT antibiotics appeared in 3 of 34 patients and were of low clinical significance.

Conclusions

Intraventricular/lumbar intrathecal antibiotics can lead to very quick CSF sterilization in postneurosurgical patients with meningitis and ventriculitis. The relapse rate of meningitis and/or ventriculitis is also very low among patients treated by IVT/IT antibiotics. Intraventricular/lumbar intrathecal administration of antibiotics appears to be an effective and safe treatment for infections of the CNS caused by multidrug-resistant organisms. In patients with signs of ventriculitis, the authors prefer the IVT route of antibiotics. This study did not prove a lower efficacy of administration of antibiotics via lumbar drainage compared with the ventricular route in patients with meningitis.

Klebsiella pneumoniae meningitis induces memory impairment and increases pro-inflammatory host response in the central nervous system of Wistar rats

Klebsiella pneumoniae meningitis has recently become an increasingly common cause of central nervous system infection. The invasion of bacteria within the subarachnoid space stimulates the release of pro-inflammatory cytokines and chemokines, triggering a host immune response. The aim of the present study was to evaluate memory and pro-inflammatory mediators at different times in the brains of adult Wistar rats with K. pneumoniae meningitis. The animals were sacrificed at 6, 12, 24, 48 and 96 h after meningitis induction. The hippocampus, frontal cortex and cerebrospinal fluid were isolated to determine the cytokine, chemokine and brain-derived neurotrophic factor (BDNF) levels. In the first 6 and 24 h following meningitis induction, there was a significant increase of the TNF-α, IL-1β, IL-6, cytokine-induced neutrophil chemoattractant-1 and BDNF levels in the central nervous system. Ten days after meningitis induction, cognitive memory was evaluated using an open-field task and step-down inhibitory avoidance task. In the control group, significant differences in behaviour were observed between the training and testing sessions for both tasks, demonstrating habituation and aversive memory. However, the meningitis group did not exhibit any difference between the training and testing sessions in either task, demonstrating memory impairment. As a result of these observations, we believe that the meningitis model may be a good research tool to study the biological mechanisms involved in the pathophysiology of this illness, while recognizing that animal models should be interpreted with caution before extrapolation to the clinic.

Spontaneous gram-negative bacillary meningitis in adult patients: characteristics and outcome

BACKGROUND

Spontaneous meningitis caused by gram-negative bacilli in adult patients is uncommon and poorly characterized. Our objective is to describe and compare the characteristics and the outcome of adult patients with spontaneous gram-negative bacilli meningitis (GNBM) and spontaneous meningitis due to other pathogens.

METHODS

Prospective single hospital-based observational cohort study conducted between 1982 and 2006 in a university tertiary hospital in Barcelona (Spain). The Main Outcome Measure: In-hospital mortality.

RESULTS

Gram-negative bacilli meningitis was diagnosed in 40 (7%) of 544 episodes of spontaneous acute bacterial meningitis. The most common pathogens were Escherichia coli and Pseudomonas species. On admission, characteristics associated with spontaneous gram-negative bacilli meningitis by multivariate modeling were advanced age, history of cancer, nosocomial acquisition of infection, urinary tract infection as distant focus of infection, absence of rash, hypotension, and a high cerebrospinal fluid white-cell count. Nine (23%) episodes were acquired in the hospital and they were most commonly caused by Pseudomonas. The in-hospital mortality rate was 53%. The mortality rate was higher among patients with Gram-negative bacillary meningitis than among those with other bacterial meningitis and their risk of death was twenty times higher than among patients infected with Neisseria meningitidis (odds ratio 20.47; 95% confidence interval 4.03-103.93; p<0.001).

CONCLUSIONS

Gram-negative bacilli cause 9% of spontaneous bacterial meningitis of known etiology in adults. Characteristics associated with GNBM include advanced age, history of cancer, nosocomial acquisition, and urinary tract infection as distant focus of infection. The mortality rate is higher among patients with gram-negative bacillary meningitis than among those with other bacterial meningitides.

Post-neurosurgical multidrug-resistant Acinetobacter baumannii meningitis successfully treated with intrathecal colistin. A new case and a systematic review of the literature

INTRODUCTION

Post-neurosurgical nosocomial meningitis has become an important subgroup of bacterial meningitis in the hospital setting. The increase in meningitis caused by multidrug-resistant (MDR) Acinetobacter baumannii has resulted in a significant reduction in available treatment options.

CASE REPORT AND LITERATURE REVIEW

We report the case of a 36-year-old man with a complex craniofacial trauma, who developed a nosocomial meningitis due to MDR A. baumannii that was cured by intrathecal colistin. The case is contextualized among all the published cases of Acinetobacter meningitis treated with topical colistin found through a MEDLINE search of the literature. To date, including the present case, eight reported cases of Acinetobacter meningitis have been treated with colistin administered by an intrathecal route and 24 by an intraventricular route. The daily dose of colistin used ranged from 1.6 mg every 24 h to 20 mg every 24 h in adult patients. The median time necessary to obtain cerebrospinal fluid sterilization was 4.1 days, and treatment was always successful even if in two cases Acinetobacter meningitis relapsed. Toxicity probably or possibly related to the topical administration of colistin was noted in five out of the 32 patients.

CONCLUSIONS

Topical colistin can be an effective and safe treatment for MDR Acinetobacter meningitis.

Gram-negative Bacillary Meningitis after Cranial Surgery or Trauma in Adults

In order to assess the clinical features, aetiology, treatment and outcome of post-neurosurgical and post-traumatic Gram-negative bacillary meningitis (GNBM) we performed a retrospective review of all adult patients admitted to the Department of Neurosurgery who had Gram-negative bacilli cultured from cerebrospinal fluid (CSF) following a neurosurgical procedure or traumatic head/spinal injury. During the 12 y of the review 33 patients had CSF isolates of Gram-negative bacilli that were thought to be significant. The median patient age was 47 y (range 22-77 y) and 21 (64%) were male. Klebsiella pneumoniae, Enterobacter cloacae and Escherichia coli were the most common isolates. Minimal inhibitory concentrations (MIC) measured for half the patients' isolates resulted in 5 regimen changes, including 2 patients with E. cloacae meningitis in whom cephalosporin susceptibility decreased during cephalosporin treatment. Our recommended initial treatment was intravenous ceftriaxone and amikacin, subsequently tailored by susceptibility results; approximately half the patients remained on the antibiotics they started and half were changed to an alternate regimen, most often a carbapenem. Five patients (15%) died, 1 dying after cure of his GNBM. There were no failures in those who received more than 12 d of appropriate treatment: treatment for at least 14 d after the last positive CSF culture guaranteed cure. Initial ceftriaxone and amikacin subsequently changing to susceptibility driven alternatives, often a carbapenem, resulted in cure of 85% of our patients with GNBM.

Improving the role of intraventricular antimicrobial agents in the management of meningitis

PURPOSE OF REVIEW

The aim is to review the role of intraventricular administration of antimicrobial agents in the treatment of patients with bacterial and fungal meningitis.

RECENT FINDINGS

This article discusses indications for intraventricular antimicrobial agents, choice of antibiotics, strategies to monitor pharmacokinetics of central nervous system compartments and unanswered issues for this management approach.

SUMMARY

Intraventricular administration of antimicrobials may be necessary in certain difficult- to- eradicate central nervous system infections. There is a significant need for clinical trials and management guidelines in this area.

Management of meningitis due to antibiotic-resistant Acinetobacter species

Acinetobacter meningitis is becoming an increasingly common clinical entity, especially in the postneurosurgical setting, with mortality from this infection exceeding 15%. Infectious Diseases Society of America guidelines for therapy of postneurosurgical meningitis recommend either ceftazidime or cefepime as empirical coverage against Gram-negative pathogens. However, assessment of the pharmacodynamics of these cephalosporins in cerebrospinal fluid suggests that recommended doses will achieve pharmacodynamic targets against fewer than 10% of contemporary acinetobacter isolates. Thus, these antibiotics are poor options for suspected acinetobacter meningitis. From in vitro and pharmacodynamic perspectives, intravenous meropenem plus intraventricular administration of an aminoglycoside may represent a superior, albeit imperfect, regimen for suspected acinetobacter meningitis. For cases of meningitis due to carbapenem-resistant acinetobacter, use of tigecycline is not recommended on pharmacodynamic grounds. The greatest clinical experience rests with use of polymyxins, although an intravenous polymyxin alone is inadvisable. Combination with an intraventricularly administered antibiotic plus removal of infected neurosurgical hardware appears the therapeutic strategy most likely to succeed in this situation. Unfortunately, limited development of new antibiotics plus the growing threat of multidrug-resistant acinetobacter is likely to increase the problems posed by acinetobacter meningitis in the future.

Intraventricular or intrathecal use of polymyxins in patients with Gram-negative meningitis: a systematic review of the available evidence

Several reports have described the use of polymyxins by the intraventricular or intrathecal route for multidrug-resistant Gram-negative meningitis. We reviewed the available clinical evidence regarding intraventricular/intrathecal administration of polymyxins in patients with meningitis, focusing on effectiveness and safety. Relevant studies were identified from PubMed (January 1950 to April 2006) as well as from the references of relevant articles. We identified 31 case reports/series that matched our inclusion criteria. Sixty-four episodes of Gram-negative meningitis (34 in adults) were reviewed. Monotherapy with polymyxins via the intraventricular or intrathecal route was used in 11 episodes and combination of systemic and local polymyxins was used in 25 episodes. In the remaining episodes, various combinations of local polymyxins with systemic and/or local antibiotics were administered. Cure was achieved in 51/64 episodes (80%); in 26/30 episodes (87%) due to Pseudomonas aeruginosa and in 10/11 episodes (91%) due to Acinetobacter spp. Toxicity related to local administration of polymyxins was noted in 17/60 (28%) patients. The most common toxicity was meningeal irritation (12 cases). Discontinuation of treatment was necessary in four episodes and dose reduction in four episodes; irreversible toxicity was not reported. The limited available evidence suggests that therapy with intraventricular/intrathecal polymyxins alone or in combination with systemic antimicrobial agents is effective against Gram-negative meningitis. Toxicity is not uncommon but it is dose-dependent and reversible. Further studies are needed to evaluate the criteria for initiation of local central nervous system treatment with polymyxins, the optimal dosages and the role of adjuvant systemic or local therapy.

Adults with spontaneous aerobic Gram-negative bacillary meningitis admitted to the intensive care unit

The characteristics of spontaneous aerobic Gram-negative bacillary meningitis (AGNBM) were determined in 40 adults requiring admission to an intensive care unit (ICU) during a 16-year period in ten French ICUs. Eight infections were hospital-acquired and most patients had predisposing factors, mainly chronic alcoholism and an immunocompromised status. Three immunosuppressed patients had disseminated strongyloidiasis. Gram's stain, cerebrospinal fluid and blood cultures were positive for 85%, 98% and 80% of cases, respectively. Escherichia coli (57%) and Klebsiella pneumoniae (17%) were the most frequent pathogens. In-ICU mortality was 38%. Spontaneous AGNBM is a rare complication of bacteraemia in adults. The severity of predisposing underlying diseases might explain the poor prognosis despite appropriate antimicrobial therapy.

Third-generation cephalosporin resistance among Gram-negative bacilli causing meningitis in neurosurgical patients: significant challenges in ensuring effective antibiotic therapy

OBJECTIVES

The treatment of meningitis caused by Gram-negative bacilli in neurosurgical patients is a major challenge because of the complexity of these patients, the emergence of antibiotic resistance in many of the causative organisms and the restricted choice of antibiotics suitable for use, owing to a failure to achieve high enough concentrations in the CSF. We reviewed the incidence, aetiology, treatment and outcome of all patients with Gram-negative bacillary meningitis (GNBM) in our centre over a 7 year period.

METHODS

Beaumont Hospital, Dublin is a 720 bed tertiary referral hospital and contains the national neurosurgical centre for the Republic of Ireland. The case notes and microbiological records of all patients with GNBM between 1998 and 2004 inclusive were reviewed retrospectively. Only patients with positive CSF culture and clinical features compatible with meningitis were included.

RESULTS

Forty separate episodes of GNBM involving 34 different patients occurred during the study period. The most common causative organisms were Enterobacter spp. (35%), Escherichia coli (22.5%) and Pseudomonas aeruginosa (15%). Twenty-five per cent of isolates were resistant to third-generation cephalosporins. The median duration of treatment was 19.2 days and a combination of intravenous and intraventricular antibiotics was the most common treatment regimen used. Mortality directly related to GNBM was 2.5%.

CONCLUSIONS

Although the mortality directly related to GNBM was low, the emergence of strains resistant to third-generation cephalosporins represents a therapeutic challenge. Treatment with combined intravenous and intraventricular antibiotics is recommended for 2-3 weeks, but more studies are required to determine the optimal management of this difficult condition.

Cure of post-traumatic recurrent multiresistant Gram-negative rod meningitis with intraventricular colistin

A 28-year-old man developed five episodes of meningitis, all due to multiresistant Gram-negative rods during his 7-month hospitalisation after head trauma. This patient's recurrent meningitis was solved only when colistin and amikacin were given by the intraventricular in addition to the intravenous route for a long period of time, specifically 6 weeks.

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.

Risk factors and prognostic indicators of bacterial meningitis in a cohort of 3580 postneurosurgical patients

In order to identify the incidence, risk factors and prognostic indicators of postneurosurgical bacterial meningitis, a 9-y retrospective cohort study was performed. The cohort comprised 3580 individuals who underwent neurosurgical operations at the Department of Neurosurgery of Catholic University, Rome, a 1,700-bed university hospital. We observed 52 episodes of postneurosurgical meningitis, with infection rates of 1.4/100 patients, 0.8/100 operations for craniotomies and 2.6/100 operations for internal cerebrospinal fluid (CSF) shunt or ventriculostomy with external drainage. The overall infection rate decreased from 2.5/100 operations in 1989 to 0.9/100 in 1997 (p = 0.03). Logistic regression analysis indicated that duration of ventriculostomy with external drainage [p < 0.01; odds ratio (OR) = 9.67; 95% confidence interval (CI) = 2.44-38.321 and increasing value of the APACHE III score (p <0.01; OR = 8.51; 95% CI = 2.15-33.68) were independent risk factors for development of meningitis. The overall case fatality rate was 8%. Predictors of mortality were low ( < 1.66 mmol/l) CSF glucose concentration (p = 0.001), increasing value of the APACHE IIl score (p = 0.002) and Gram-negative aetiology (p = 0.003).

Protean infectious types and frequent association with neurosurgical procedures in adult Serratia marcescens CNS infections: report of two cases and review of the literature

Serratia marcescens is a rare pathogen of adult central nervous system (CNS) infection. We report on the clinical features and therapeutic outcomes of two adult patients with such infections. The clinical characteristics of 13 other reported adult cases are also included for analysis. The 15 cases were nine males and six females, aged 19-83 years, in whom, underlying post-neurosurgical states and ear operation were noted in 93% (14/15). Fever and conscious disturbance were the most common clinical manifestations of these 15 cases, followed by hydrocephalus, seizures, and wound infections. The manifestation types were protean, including meningitis and focal suppurations such as brain abscess, cranial and spinal epidural abscess, cranial subdural abscess, and infected lumbar pseudomeningocele. One case of S. marcescens CNS infection was diagnosed postmortem; the other 14 were diagnosed by the positive culture from CSF or pus. Antibiotic therapy with or without neurosurgical intervention was the management strategy in 14/15 cases. The therapeutic results showed a high mortality rate.

Cerebrospinal fluid

A quick and accurate diagnosis of maladies affecting the central nervous system (CNS) is imperative. Procurement and analysis of cerebrospinal fluid (CSF) are paramount in helping the clinician determine a patient's clinical condition. Various staining methods, measurement of white blood cell counts, glucose and protein levels, recognition of xanthochromia, and microbiologic studies are CSF parameters that are collectively important in the ultimate determination by a clinician of the presence or absence of a catastrophic CNS condition. Many of these CNS parameters have significant limitations that should be recognized to minimize under treating patients with catastrophic illness.

Gram-negative bacillary meningitis in adult post-neurosurgical patients

BACKGROUND

To assess the clinical features and therapeutic outcomes of gram-negative bacillary meningitis (GNBM) in adult postneurosurgical patients.

METHODS

Thirty adult patients with GNBM were included in this study. Their clinical features, laboratory data, prognostic factors, and therapeutic outcome were analyzed. The patients were 22 males and 8 females, aged 17-72 years. Seven had community-acquired infections and 23 had nosocomial infections. Two patients were associated with brain abscess.

RESULTS

The pathogens found in the 30 GNBM patients were Pseudomonas aeruginosa, Klebsiella species, Escherichia coli, Acinetobacter baumannii, and some rare pathogens including Citrobacter freundii, Serratia marcescens, Enterobacter cloacae, and Proteus mirabilis. Among these 30 patients, 8 patients with third-generation cephalosporin-resistant GNBM were identified since 1994; all infections were nosocomially acquired. Appropriate antibiotics were given to 22 patients. Eight patients did not receive appropriate antibiotic therapy. All eight died. The mortality rate in those treated with appropriate antibiotics was 14%.

CONCLUSIONS

There has been an increase of GNBM in postneurosurgical patients in recent years. In addition, the emergence of strains resistant to third-generation cephalosporins in this specific group of patients has also been noted in recent years, and has become a great therapeutic challenge. We noted many prognostic factors in postneurosurgical patients in this study; however, appropriate antibiotic therapy and initial consciousness level are the most significant ones. Therefore, in cases of postneurosurgical patients with nosocomially acquired GNBM, the possibility of third-generation cephalosporin resistance should be strongly suspected. Early initiation of appropriate antibiotic therapy is needed in this potentially fatal disease.

Enterobacteriaceae meningitis in adults: a review of 20 consecutive cases 1977-97

Enterobacteriaceae are not a frequent cause of meningitis in adults and are seen mainly in neurosurgical patients and on occasion in elderly and debilitated patients. Consequently, most series studied have been small and selected. In order to obtain a clearer clinical picture, we reviewed 20 consecutive cases of Enterobacteriaceae meningitis admitted to the Department of Infectious Diseases, Rigshospitalet, Copenhagen, during the years 1977-97. They comprised 1.5% of all cases of acute bacterial meningitis admitted to the department. All of the patients were either elderly and/or had 1 or more underlying diseases and predisposing factors. The clinical presentation and cerebrospinal fluid findings were not different from that of acute bacterial meningitis in general. The mortality rate was 40% and correlated with simultaneous bacteraemia. Complications were seen in a further 30% of patients and 25% survived with different sequelae. These high rates may, at least in part, be due to the advanced age and debilitated state of the patients studied. Escherichia coli was the most frequent of the Enterobacteriaceae.

Clinical presentations, diagnosis, and prognostic factors of bacterial meningitis

The clinical presentations of children and adults with bacterial meningitis have not changed over the past several decades, and a high index of suspicion remains critical for timely identification of infected patients. With the virtual disappearance of H. influenzae type B meningitis (Hib) in areas of the world where Hib conjugate vaccine is administered routinely, the utility of commercially available tests for rapid detection of bacterial polysaccharides has diminished. Detection of gene products of meningeal pathogens in cerebrospinal fluid or blood is still experimental. The prognostic findings of recent studies are not different from those previously described, despite advances in the supportive care of critically ill patients.

Resistance to third-generation cephalosporins in adult gram-negative bacillary meningitis

Ninety-three patients with gram-negative bacillary meningitis (GNBM) were identified at Kaohsiung Chang Gung Memorial Hospital, over a period of 12 years. Among them, eight showed resistance to third-generation cephalosporins, accounting for 9% of the total GNBM cases and 29% of the postneurosurgical GNBM cases. The resistant pathogens included Acinetobacter baumannii, Klebsiella pneumoniae, Citrobacter freundii and Morganella morganii. These eight patients, six males and two females aged 18-61 years, all had nosocomially acquired meningitis associated with head trauma and/or postneurosurgical states. Six patients received imipenem/cilastatin treatment; five survived and one died. The other two expired because they did not receive appropriate antibiotic treatment. Although third-generation cephalosporin-resistant GNBM is rare, its incidence has been increasing over the past 5 years. In patients with nosocomially-acquired postneurosurgical GNBM, the presence of third-generation cephalosporin resistance should therefore be highly suspected. The appropriate choice of antibiotic is essential for their survival.

The prognostic factors of adult gram-negative bacillary meningitis

Seventy-seven patients with Gram-negative bacillary meningitis (GNBM), 57 males and 20 females, aged 17-86 years, were identified at Kaohsiung Chang Gung Memorial Hospital, over an 11-year period. Fifty-four infections were community-acquired, and 23 were nosocomial; 49 were spontaneous and 28 occurred after head surgery or neurosurgery. The organisms most frequently involved were Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter. Rarer pathogens included Citrobacter species, Serratia marcescens, Enterobacter cloacae, and Proteus mirabilis. All patients who did not receive appropriate antibiotic therapy died. The mortality in those treated with appropriate antibiotics was 28%. Other statistically significant prognostic factors included septic shock, initial level of consciousness, hyperosmolar hyperglycemic nonketotic coma, disseminated intravascular coagulation, high cerebrospinal fluid lactate levels and leucocytosis. In the multiple logistic regression analysis, only appropriate antimicrobial therapy and septic shock were strongly associated with mortality even after adjusting for other potentially confounding factors. Despite the high mortality, management can be improved by early diagnosis, early use of appropriate antibiotics, and correction of underlying and associated medical derangement.

Successful transplantation of organs retrieved from donors with bacterial meningitis

BACKGROUND

The shortage of organs for transplantation is the most important factor limiting the number of transplants performed. Consequently, in recent years, criteria for considering a patient as a potential organ donor have been broadened.

METHODS

From 1995 through 1996, we have retrieved organs from five donors who were brain dead because of bacterial meningitis. The causative microorganisms were Neisseria meningitidis in one patient, Streptococcus pneumoniae in three patients, and Escherichia coli in one patient. Fifteen organs were retrieved and transplanted into 16 recipients. All the donors and recipients received adequate antibiotic therapy.

RESULTS

None of the recipients developed infectious complications caused by the meningeal pathogens. After a follow-up ranging from 4 to 30 months, 12 patients are alive with functioning grafts. The cause of death was noninfectious in the four patients who died.

CONCLUSIONS

Our study demonstrates that patients with brain death caused by bacterial meningitis due to meningococci, pneumococci, or E coli may be suitable organ donors. Transplantation of organs from such donors does not increase the risk of infection transmission to the recipient, provided that both donor and recipient had received adequate antibiotic therapy.

Gram-negative enteric bacillary meningitis: a twenty-one-year experience

We reviewed our experience with gram-negative enteric bacillary meningitis in neonates and infants from 1969 through 1989. Ninety-eight patients were identified. Their ages were from 1 day to 2 years with a median of 10 days. In 25 patients (26%), predisposing factors were identified, the most common of which were neural tube defects and urinary tract anomalies. The causative agents were Escherichia coli (53%), Klebsiella-Enterobacter species (16%), Citrobacter diversus (9%), Salmonella species (9%), Proteus mirabilis (4%), Serratia marcescens (3%), Bacteroides fragilis (3%), and Aeromonas species (2%). At the time of diagnosis, Gram-stained smears of cerebrospinal fluid revealed gram-negative bacilli in 61% of patients. The causative organism was cultured from blood obtained from 55% of patients, and 21% had positive urine culture results. The cerebrospinal fluid leukocyte counts ranged from 0 to 80,600 cells/mm3, and the cerebrospinal fluid/serum glucose concentration ratio was less than 0.5 in 72% of patients. Antimicrobial regimens varied greatly. After initiation of antibiotic therapy, an average of 3 days was needed for eradication of bacteria from cerebrospinal fluid. The case-fatality rate was 17%, and 61% of survivors had long-term sequelae that included seizure disorders, hydrocephalus, physical disability, developmental delay, and hearing loss.

Fever of unknown origin following traumatic brain injury

Fever is a common complication of a traumatic brain injury, occurring during both the acute-care phase and the rehabilitation phase of recovery. The aetiology of fever in this population may remain obscure because of the presence of cognitive confusion associated with post-traumatic amnesia interfering with history taking and the difficult physical examination. We present a case where recovery from a traumatic brain injury was complicated by a fever of unknown origin that proved to be secondary to lateral sinus thrombophlebitis. This case emphasises the importance of a thorough knowledge of the differential diagnosis for fever that is unique to the traumatic brain injury population.