Dexamethasone therapy for bacterial meningitis. Results of two double-blind, placebo-controlled trials

Corticosteroids for bacterial keratitis: the Steroids for Corneal Ulcers Trial (SCUT)

OBJECTIVE

To determine whether there is a benefit in clinical outcomes with the use of topical corticosteroids as adjunctive therapy in the treatment of bacterial corneal ulcers.

METHODS

Randomized, placebo-controlled, double-masked, multicenter clinical trial comparing prednisolone sodium phosphate, 1.0%, to placebo as adjunctive therapy for the treatment of bacterial corneal ulcers. Eligible patients had a culture-positive bacterial corneal ulcer and received topical moxifloxacin for at least 48 hours before randomization.

MAIN OUTCOME MEASURES

The primary outcome was best spectacle-corrected visual acuity (BSCVA) at 3 months from enrollment. Secondary outcomes included infiltrate/scar size, reepithelialization, and corneal perforation.

RESULTS

Between September 1, 2006, and February 22, 2010, 1769 patients were screened for the trial and 500 patients were enrolled. No significant difference was observed in the 3-month BSCVA (-0.009 logarithm of the minimum angle of resolution [logMAR]; 95% CI, -0.085 to 0.068; P = .82), infiltrate/scar size (P = .40), time to reepithelialization (P = .44), or corneal perforation (P > .99). A significant effect of corticosteroids was observed in subgroups of baseline BSCVA (P = .03) and ulcer location (P = .04). At 3 months, patients with vision of counting fingers or worse at baseline had 0.17 logMAR better visual acuity with corticosteroids (95% CI, -0.31 to -0.02; P = .03) compared with placebo, and patients with ulcers that were completely central at baseline had 0.20 logMAR better visual acuity with corticosteroids (-0.37 to -0.04; P = .02).

CONCLUSIONS

We found no overall difference in 3-month BSCVA and no safety concerns with adjunctive corticosteroid therapy for bacterial corneal ulcers.

APPLICATION TO CLINICAL PRACTICE

Adjunctive topical corticosteroid use does not improve 3-month vision in patients with bacterial corneal ulcers.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00324168.

Adjunctive oral methylprednisolone in pediatric acute pyelonephritis alleviates renal scarring

OBJECTIVE

To determine if glucocorticoids can prevent renal scar formation after acute pyelonephritis in pediatric patients.

METHODS

Patients younger than 16 years diagnosed with their first episode of acute pyelonephritis with a high risk of renal scar formation (ie, inflammatory volume ≥ 4.6 mL on technetium-99m-labeled dimercaptosuccinic acid scan [DMSA] or abnormal renal ultrasonography results) were randomly assigned to receive either antibiotics plus methylprednisolone sodium phosphate (1.6 mg/kg per day for 3 days [MPD group]) or antibiotics plus placebo (placebo group) every 6 hours for 3 days. Patients were reassessed by using DMSA 6 months after treatment. The primary outcome was the development of renal scars.

RESULTS

A total of 84 patients were enrolled: 19 in the MPD group and 65 in the placebo group. Patient characteristics were similar between the 2 groups, including the acute inflammatory parameters and the initial DMSA result. Renal scarring was found in 33.3% of children treated with MPD and in 60.0% of those who received placebo (P < .05). The median cortical defect volumes on follow-up DMSA were 0.0 mL (range: 0-4.5 mL) and 1.5 mL (range: 0-14.8 mL) for the MPD and placebo groups, respectively (P < .01). Patients in the MPD group experienced faster defervescence after treatment than the placebo group.

CONCLUSIONS

Adjunctive oral MPD therapy reduced the occurrence and/or severity of renal scarring after acute pyelonephritis in these hospitalized children who had a high risk of renal scar formation.

Pathophysiology and treatment of bacterial meningitis

Bacterial meningitis is a medical emergency requiring immediate diagnosis and immediate treatment. Streptococcus pneumoniae and Neisseria meningitidis are the most common and most aggressive pathogens of meningitis. Emerging antibiotic resistance is an upcoming challenge. Clinical and experimental studies have established a more detailed understanding of the mechanisms resulting in brain damage, sequelae and neuropsychological deficits. We summarize the current pathophysiological concept of acute bacterial meningitis and present current treatment strategies.

Bioanalysis of meningococcal vaccines

Meningococcal meningitis is feared because of the rapid onset of severe disease from mild symptoms and, therefore, is an important target for vaccine research. Five serogroups, defined by the structures of their capsular polysaccharides, are responsible for the vast majority of disease. Protection against four of these five serogroups can be obtained with polysaccharide or glycoconjugate vaccines, in which fragments of the capsular polysaccharides attached to a carrier protein generate anticarbohydrate immune responses, whilst protection against group B disease requires protein immunogens, often presented in vesicles containing outer membrane proteins. Glycoconjugate vaccines are now an established technology, but outer-membrane protein vaccines are still under development and present significant challenges. This review discusses physicochemical approaches to the characterization and quality control of these vaccines, as well as highlighting the problems and differences in vaccine design required for protection against different serogroups of the same species of pathogen.

Meta-research: The art of getting it wrong

Meta-analysis has major strengths, but sometimes it can often lead to wrong and misleading answers. In this SRSM presidential address, I discuss some case studies that exemplify these problems, including examples from meta-analyses of both clinical trials and observational associations. I also discuss issues of effect size estimation, bias (in particular significance-chasing biases), and credibility in meta-research. I examine the factors that affect the credibility of meta-analyses, including magnitude of effects, multiplicity of analyses, scale of data, flexibility of analyses, reporting, and conflicts of interest. Under the current circumstances, a survey of expert meta-analysts attending the SRSM meeting showed that most of them believe that the true effect is practically equally likely to lie within the 95% confidence interval of a meta-analysis or outside of it. Finally, I address the placement of meta-analysis in the wider current research agenda and make a plea for adoption of more prospective meta-designs. In many/most/all fields, all primary original research may be designed, executed, and interpreted as a prospective meta-analysis. Copyright © 2011 John Wiley & Sons, Ltd.

Association of bacteria with hydrocephalus in Ugandan infants

OBJECT

Infantile hydrocephalus in East Africa is predominantly postinfectious. The microbial origins remain elusive, since most patients present with postinfectious hydrocephalus after antecedent neonatal sepsis (NS) has resolved.

METHODS

To characterize this syndrome in Ugandan infants, the authors used polymerase chain reaction targeting bacterial 16S ribosomal DNA from CSF to determine if bacterial residua from recent infections were detectable. Bacteria were identified based on the relationship of genetic sequences obtained with reference bacteria in public databases. The authors evaluated samples from patients presenting during dry and rainy seasons and performed environmental sampling in the villages of patients.

RESULTS

Bacterial DNA was recovered from 94% of patients. Gram-negative bacteria in the phylum Proteobacteria were the most commonly detected. Within this phylum, Gammaproteobacteria dominated in patients presenting after infections during the rainy season, and Betaproteobacteria was most common following infections during the dry season. Acinetobacter species were identified in the majority of patients admitted after rainy season infection.

CONCLUSIONS

Postinfectious hydrocephalus in Ugandan infants appears associated with predominantly enteric gram-negative bacteria. These findings highlight the need for linking these cases with antecedent NS to develop more effective treatment and prevention strategies.

Corticosteroids for acute bacterial meningitis

BACKGROUND

In experimental studies, the outcome of bacterial meningitis has been related to the severity of inflammation in the subarachnoid space. Corticosteroids reduce this inflammatory response.

OBJECTIVES

To examine the effect of adjuvant corticosteroid therapy versus placebo on mortality, hearing loss and neurological sequelae in people of all ages with acute bacterial meningitis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, issue 1), MEDLINE (1966 to February 2010), EMBASE (1974 to February 2010) and Current Contents (2001 to February 2010).

SELECTION CRITERIA

Randomised controlled trials (RCTs) of corticosteroids for acute bacterial meningitis.

DATA COLLECTION AND ANALYSIS

We scored RCTs for methodological quality. We collected outcomes and adverse effects. We performed subgroup analyses for children and adults, causative organisms, low-income versus high-income countries, time of steroid administration and study quality.

MAIN RESULTS

Twenty-four studies involving 4041 participants were included. Similar numbers of participants died in the corticosteroid and placebo groups (18.0% versus 20.0%; risk ratio (RR) 0.92, 95% confidence interval (CI) 0.82 to 1.04, P = 0.18). There was a trend towards lower mortality in adults receiving corticosteroids (RR 0.74, 95% CI 0.53 to 1.05, P = 0.09). Corticosteroids were associated with lower rates of severe hearing loss (RR 0.67, 95% CI 0.51 to 0.88), any hearing loss (RR 0.76, 95% CI 0.64 to 0.89) and neurological sequelae (RR 0.83, 95% CI 0.69 to 1.00).Subgroup analyses for causative organisms showed that corticosteroids reduced severe hearing loss in Haemophilus influenzae meningitis (RR 0.34, 95% CI 0.20 to 0.59) and reduced mortality in Streptococcus pneumoniae meningitis (RR 0.84, 95% CI 0.72 to 0.98).In high-income countries, corticosteroids reduced severe hearing loss (RR 0.51, 95% CI 0.35 to 0.73), any hearing loss (RR 0.58, 95% CI 0.45 to 0.73) and short-term neurological sequelae (RR 0.64, 95% CI 0.48 to 0.85). There was no beneficial effect of corticosteroid therapy in low-income countries.Subgroup analysis for study quality showed no effect of corticosteroids on severe hearing loss in high quality studies.Corticosteroid treatment was associated with an increase in recurrent fever (RR 1.27, 95% CI 1.09 to 1.47), but not with other adverse events.

AUTHORS' CONCLUSIONS

Corticosteroids significantly reduced hearing loss and neurological sequelae, but did not reduce overall mortality. Data support the use of corticosteroids in patients with bacterial meningitis in high-income countries. We found no beneficial effect in low-income countries.

Central nervous system infections as a cause of an altered mental status? What is the pathogen growing in your central nervous system?

There are several central nervous system (CNS) infections (meningitis, encephalitis, and brain abscess), any of which may present with an altered level of consciousness. Because CNS infections can have a devastating outcome, it is important to recognize the presence of a CNS infection and begin treatment as soon as possible because early appropriate therapy may, in some cases, limit morbidity and mortality.

Epidemiology, diagnosis, and antimicrobial treatment of acute bacterial meningitis

The epidemiology of bacterial meningitis has changed as a result of the widespread use of conjugate vaccines and preventive antimicrobial treatment of pregnant women. Given the significant morbidity and mortality associated with bacterial meningitis, accurate information is necessary regarding the important etiological agents and populations at risk to ascertain public health measures and ensure appropriate management. In this review, we describe the changing epidemiology of bacterial meningitis in the United States and throughout the world by reviewing the global changes in etiological agents followed by specific microorganism data on the impact of the development and widespread use of conjugate vaccines. We provide recommendations for empirical antimicrobial and adjunctive treatments for clinical subgroups and review available laboratory methods in making the etiological diagnosis of bacterial meningitis. Finally, we summarize risk factors, clinical features, and microbiological diagnostics for the specific bacteria causing this disease.

Adjunctive dexamethasone in bacterial meningitis: a meta-analysis of individual patient data

BACKGROUND

Dexamethasone improves outcome for some patients with bacterial meningitis, but not others. We aimed to identify which patients are most likely to benefit from dexamethasone treatment.

METHODS

We did a meta-analysis of individual patient data from the randomised, double-blind, placebo-controlled trials of dexamethasone for bacterial meningitis in patients of all ages for which raw data were available. The pre-determined outcome measures were death at the time of first follow-up, death or severe neurological sequelae at 1 month follow-up, death or any neurological sequelae at first follow-up, and death or severe bilateral hearing loss at first follow-up. Combined odds ratios (ORs) and tests for heterogeneity were calculated using conventional Mantel-Haenszel statistics. We also did exploratory analysis of hearing loss among survivors and other exploratory subgroup analyses by use of logistic regression.

FINDINGS

Data from 2029 patients from five trials were included in the analysis (833 [41.0%] aged <15 years). HIV infection was confirmed or likely in 580 (28.6%) patients and bacterial meningitis was confirmed in 1639 (80.8%). Dexamethasone was not associated with a significant reduction in death (270 of 1019 [26.5%] on dexamethasone vs 275 of 1010 [27.2%] on placebo; OR 0.97, 95% CI 0.79-1.19), death or severe neurological sequelae or bilateral severe deafness (42.3%vs 44.3%; 0.92, 0.76-1.11), death or any neurological sequelae or any hearing loss (54.2%vs 57.4%; 0.89, 0.74-1.07), or death or severe bilateral hearing loss (36.4%vs 38.9%; 0.89, 0.73-1.69). However, dexamethasone seemed to reduce hearing loss among survivors (24.1%vs 29.5%; 0.77, 0.60-0.99, p=0.04). Dexamethasone had no effect in any of the prespecified subgroups, including specific causative organisms, pre-dexamethasone antibiotic treatment, HIV status, or age. Pooling of the mortality data with those of all other published trials did not significantly change the results.

INTERPRETATION

Adjunctive dexamethasone in the treatment of acute bacterial meningitis does not seem to significantly reduce death or neurological disability. There were no significant treatment effects in any of the prespecified subgroups. The benefit of adjunctive dexamethasone for all or any subgroup of patients with bacterial meningitis thus remains unproven.

FUNDING

Wellcome Trust UK.

Hearing impairment in childhood bacterial meningitis is little relieved by dexamethasone or glycerol

OBJECTIVE

Several studies have evaluated dexamethasone for prevention of hearing loss in childhood bacterial meningitis, but results have varied. We compared dexamethasone and/or glycerol recipients with placebo recipients, and measured hearing at 3 threshold levels.

METHODS

Children aged 2 months to 16 years with meningitis were treated with ceftriaxone but were double-blindly randomly assigned to receive adjuvant dexamethasone intravenously, glycerol orally, both agents, or neither agent. We used the Glasgow coma scale to grade the presenting status. The end points were the better ear's ability to detect sounds of >40 dB, >or=60 dB, and >or=80 dB, with these thresholds indicating any, moderate-to-severe, or severe impairment, respectively. All tests were interpreted by an external audiologist. Influence of covariates in the treatment groups was examined by binary logistic regression.

RESULTS

Of the 383 children, mostly with meningitis caused by Haemophilus influenzae type b or Streptococcus pneumoniae, 101 received dexamethasone, 95 received dexamethasone and glycerol, 92 received glycerol, and 95 received placebo. Only the presenting condition and young age predicted impairment independently through all threshold levels. Each lowering point in the Glasgow scale increased the risk by 15% to 21% (odds ratio: 1.20, 1.21, and 1.15 [95% confidence interval: 1.06-1.35, 1.07-1.37, and 1.01-1.31]; P = .005, .003, and .039) for any, moderate-to-severe, or severe impairment, respectively. Each increasing month of age decreased the risk by 2% to 6% (P = .0001, .0007, and .041, respectively). Neither dexamethasone nor glycerol prevented hearing loss at these levels regardless of the causative agent or timing of antimicrobial agent.

CONCLUSIONS

With bacterial meningitis, the child's presenting status and young age are the most important predictors of hearing impairment. Little relief is obtained from current adjuvant medications.

Immunological and biochemical correlates of adjunctive dexamethasone in Vietnamese adults with bacterial meningitis

Adjunctive treatment to improve outcome from bacterial meningitis has centered on dexamethasone. Among Vietnamese patients with bacterial meningitis, cerebrospinal fluid (CSF) opening pressure and CSF:plasma glucose ratios were significantly improved and levels of CSF cytokines interleukin (IL)-6, IL-8, and IL-10 and were all statistically significantly lower after treatment in patients who were randomized to dexamethasone, compared with levels in patients who received placebo.

Clinical characteristics of Haemophilus influenzae meningitis in Denmark in the post-vaccination era

The introduction of Haemophilus influenzae type b (Hib) vaccine into the Danish childhood vaccination programme in 1993 may have influenced the epidemiology of H. influenzae meningitis (i.e. increasing frequency of other non-vaccine types; presentation in other age groups). Based on nationwide registration, clinical information and laboratory findings were collected from all 65 confirmed cases of H. influenzae meningitis during the period 1994-2005. Twenty-nine patients (45%) were <13 years old [median 15 months (range 0-147)], and 36 patients (55%) were >24 years old [median 62 years (range 25-96)]. Hib accounted for 31% (20/65) of the cases, and significantly more children were infected with Hib compared with adults [53% (16/29) vs. 11% (4/36), respectively, p 0.0003]. Overall, 38% of cases had an otogenic focus and this was thus the most frequent primary focus of infection. Among children infected with Hib, two cases (13%) were identified as true vaccine failures. Six patients (9%) died; one premature infant infected with serotype f and five adults (age 83-96 years) with non-typeable H. influenzae. Hearing loss was reported in 16% of the surviving children and in 10% of the surviving adults. The presence of a lung focus was an independent prognostic factor for an unfavourable outcome (p 0.03). In conclusion, meningitis caused by Hib has been infrequent in Denmark after introduction of the Hib vaccine in the childhood vaccination programme, and no increase in meningitis cases due to non-b type H. influenzae has been observed. Cases with H. influenzae meningitis frequently had an otogenic focus, with low risk of an unfavourable outcome.

[Corticosteroids in children with bacterial meningitis: indications and administration]

The use of dexamethasone (DXM) as adjunctive therapy for bacterial meningitis (BM) in infants and children has remained controversial for 20 years. In spite of solid pathophysiological arguments, the limited number of patients, methodological flaws in clinical studies taken individually and pooled into meta-analyses, and the emergence of pneumococcal cephalosporin-resistance did not allow to reach a consensus on the effectiveness of DXM in the prevention of neurological sequelae, in the course of non Haemophilus influenzae b (Hib) BM. A recent meta-analysis conducted with an adequate number of patients (2,750 patients including 2,074 infants and children below 15 years of age) demonstrated that DXM prevented mortality and sequelae in adults with pneumococcal meningitis and suggested that this efficacy could also apply to infants and children. Data from the active surveillance networks of pediatric BM and pneumococcal resistance in France suggested that DXM anti-inflammatory effect on antibiotic CSF penetration would not have a significant impact on the bactericidal efficacy if recommended dosages of cefotaxime (300 mg/kg per day) and vancomycin (60 mg/kg per day) were used. DXM could be considered in the early treatment of pneumococcal BM in infants and children in industrialized countries. But there is no proven efficacy of DXM in meningococcal meningitis in infants and children.

Central nervous system infections

Central nervous system infections have long been recognized as among the most devastating of diseases. This article describes the changing pattern and epidemiology of a variety of common central nervous system infections, including meningitis, encephalitis, and brain abscesses, and reviews pathophysiology and the most current approach to clinical diagnosis, treatment, and disposition from the emergency physician perspective.

Treatment with protein synthesis inhibitors improves outcomes of secondary bacterial pneumonia after influenza

Pneumonia occurring as a secondary infection after influenza is a major cause of excess morbidity and mortality, despite the availability and use of antibiotics active against Streptococcus pneumoniae. We hypothesized that the use of a bacteriostatic protein synthesis inhibitor would improve outcomes by reducing the inflammatory response. BALB/cJ mice infected with influenza virus and superinfected with S. pneumoniae were treated with either the cell-wall-active antibiotic ampicillin or the protein synthesis inhibitor clindamycin or azithromycin. In the model, ampicillin therapy performed significantly worse (survival rate, 56%) than (1) clindamycin therapy used either alone (82%) or in combination with ampicillin (80%) and (2) azithromycin (92%). Improved survival appeared to be mediated by decreased inflammation manifested as lower levels of inflammatory cells and proinflammatory cytokines in the lungs and by observation of less-severe histopathologic findings. These data suggest that beta-lactam therapy may not be optimal as a first-line treatment for community-acquired pneumonia when it follows influenza.

Outcome of acute necrotizing encephalopathy in relation to treatment with corticosteroids and gammaglobulin

OBJECTIVE

To examine the relation between outcome and treatment with steroids and gammaglobulin in children with acute necrotizing encephalopathy.

METHODS

We retrospectively evaluated the clinical course and outcome of 34 children with acute necrotizing encephalopathy. They were divided into two groups; 17 patients with brainstem lesion and 17 patients without brainstem lesion. Early steroid use was defined as when steroids were administered within 24h after the onset. The outcome was judged as good when a patient had no or mild cognitive impairment and poor when a patient had more severe sequelae, or died.

RESULTS

Among patients without brainstem lesions, the outcome was good in 7 of 12 with early steroid, whereas it was poor in all 5 patients without early steroid. There was no significant difference in sex, age, and laboratory data between patients with and without early steroid. The outcome was not correlated with gammaglobulin treatment. As to patients without brainstem lesions, the outcome was not correlated with early steroid or gammaglobulin treatment.

CONCLUSIONS

Steroid within 24 h after the onset was related to better outcome of children with acute necrotizing encephalopathy without brainstem lesions. Early steroid treatment will be an important option of the treatment for acute necrotizing encephalopathy.

Increase in serum osmolality is possible mechanism for the beneficial effects of glycerol in childhood bacterial meningitis

BACKGROUND

Oral glycerol reduces severe neurologic sequelae in childhood bacterial meningitis, but the mechanism awaits elucidation. We conducted a prospective, randomized, double-blind study in which the effects of glycerol and intravenous dexamethasone were compared with placebo recipients in an intensive care setting in India.

METHODS

Thirty-six children at age 2 months to 12 years with meningitis were treated with ceftriaxone and were randomized to receive also either dexamethasone intravenously, or glycerol orally, or both agents, or neither. The illness was monitored with preset criteria. The primary outcome measures were the changes in plasma osmolality and in urine output.

RESULTS

Nine children received glycerol, 8 dexamethasone, 11 both agents, and 8 only placebo. The leading agents identified were Streptococcus pneumoniae, Haemophilus influenzae type b, and Staphylococcus aureus. Only the glycerol recipients increased plasma osmolality by up to 3% from the mean baseline of 294 mOsm/kg in the glycerol and 295 mOsm/kg in the glycerol-dexamethasone group. This change occurred within 6 hours, the critical period of treatment, and lasted <24 hours. Blood pressure was not affected, nor did urine output increase. The dexamethasone-only and placebo-only recipients showed immediate decrease in serum osmolality.

CONCLUSIONS

Because excretion of the cerebrospinal fluid is inversely associated with plasma osmolality, we suggest that the glycerol-induced osmolality increase reduce the volume of cerebrospinal fluid, enhanced water movement back to the plasma by osmosis, increased cerebral blood flow, and thus, improved brain oxygenation.

The role of dexamethasone on decreasing urinary cytokines in children with acute pyelonephritis

Cytokines play a major role in renal scar formation following febrile urinary tract infection (UTI). We investigated the role of dexamethasone combined with antibiotics in diminishing urinary interleukin-6 (UIL-6) and UIL-8 concentrations during the acute phase of pyelonephritis compared with standard antibiotic therapy. UIL-6 and UIL-8 concentrations were determined by enzyme immunoassay in 34 children with pyelonephritis who were treated with ceftriaxone plus dexamethasone (case group) and in 20 patients with the same diagnosis treated with ceftriaxone alone (control group). Urine samples were obtained at the time of presentation prior to drug administration and at follow-up 72 h after initiation of medication. Creatinine concentrations were also determined, and cytokine/creatinine ratios were calculated to standardize samples. Differences between cytokine/creatinine ratios in initial and follow-up urine samples were significant in the case group (P < 0.001) but not for controls. In addition, combined antibiotic and dexamethasone significantly decreased UIL-6 and UIL-8 concentrations compared with antibiotic alone (P < 0.05). We conclude that dexamethasone combined with antibiotics significantly decreases UIL-6 and UIL-8 levels in patients with acute pyelonephritis. This suggests that the clinical use of corticosteroids may prevent scar formation following febrile UTI.

Acute bacterial meningitis

Despite advances in medical care including antibiotics and vaccines, meningitis still has a high morbidity and mortality rate, especially in certain high-risk patients. Early diagnosis with the administration of appropriate antibiotics remains the key element of management. This article highlights methods of diagnosis, differential diagnoses, treatment options, and complications of treating bacterial meningitis.

Adrenal insufficiency in prolonged critical illness

INTRODUCTION

Adrenal insufficiency is common in critically ill patients and affects their prognosis, but little is known about how adrenal function changes during prolonged critical illness. This study was conducted to investigate dynamic changes in cortisol levels in patients with critical illness who do not improve after treatment.

METHODS

This observational cohort study was performed in the intensive care units of a university hospital. We studied acutely ill patients with initial cortisol level above 34 microg/dl, but who did not improve after treatment and in whom follow-up cortisol levels were determined during critical illness. All clinical information and outcomes were recorded.

RESULTS

Fifty-seven patients were included. Ten patients had follow-up cortisol levels above 34 microg/dl, 32 patients had levels between 34 and 15 microg/dl, and 15 patients had levels under 15 microg/dl. Outcomes did not differ significantly among the three groups with different follow-up cortisol levels. In Cox regression analysis, those patients who survived to hospital discharge with second cortisol levels under 15 microg/dl had a longer hospital length of stay (odds ratio = 14.8, 95% confidence interval = 2.4 to 90.0; P = 0.004).

CONCLUSION

The majority of acutely ill patients who remained in a critical condition had decreased serum cortisol levels. Depressed cortisol levels at follow up may lead to worse clinical outcomes. We propose that repeated adrenal function testing be conducted in patients with prolonged critical illness.

Bacterial meningitic deafness: historical development of epidemiology and cellular pathology

Meningitis resulting in labyrinthitis and its associated hearing loss was first described by several authors during 1864 and 1865 but it was not integrated into the otological cannon until H. Knapp's publications of 1871. These reports were incorporated by St John Rossa in his textbook of 1873. Politzer, in 1882, included a fuller description of the clinical symptoms. Analysis of records of the etiologies of students in 90 schools for the deaf in North America from 1817 to 1893 showed that before the mid-1870s meningitis was rarely identified as an etiology (<1%) but by the 1880s it accounted for 10-20% of all etiologies, with male preponderance. Cellular pathology of meningitic labyrinthitis from the 1860s to the 1990s examined the ways in which bacteria invaded the inner ear. Human temporal bone studies were a major source of understanding of the pathological processes. Honda, in 1927, injected guinea pigs intracranially with live bacteria, and observed the effects on the membranous labyrinth. In 1988 Lebel's observation of the effectiveness of dexamethasone in preventing much deafness from meningitis stimulated the examination of the labyrinthine immune response. Immunological mechanisms can account for some of the variable morbidity of unilateral, progressive, less-than-severe deafness.

Dexamethasone decreases cerebrospinal fluid soluble tumor necrosis factor receptor 1 levels in bacterial meningitis

It is known that the use of adjunctive dexamethasone in bacterial meningitis reduces audiologic and neurologic sequelae. The cerebrospinal fluid (CSF) level of soluble tumor necrosis factor 1 (sTNFR1) is an important indicator of neurologic sequelae in bacterial meningitis. We measured the CSF levels of IL-6 and sTNFR1 before administration of antibiotics (CSF1) and 1-3 days after administration of antibiotics (CSF2) in nine patients with bacterial meningitis who received dexamethasone sodium and five without dexamethasone. The CSF2 IL-6 levels of patients with/without dexamethasone were significantly lower than for CSF1 IL-6 levels (p = 0.0077, and p = 0.0431, respectively). There were no significant differences of the ratio of CSF2/CSF1 IL-6 levels between patients with dexamethasone and those without dexamethasone. CSF2 sTNFR1 levels of patients with dexamethasone were significantly lower than for CSF1 sTNFR1 levels (p = 0.0208). However, CSF2 sTNFR1 levels of patients without dexamethasone were significantly higher than for CSF1 sTNFR1 levels (p = 0.0422). The ratio of CSF2/CSF1 sTNFR1 levels of patients with dexamethasone was significantly lower than that without dexamethasone (p = 0.0063). Our present study suggests that dexamethasone inhibits increase of CSF sTNFR1 levels after antibiotics therapy in bacterial meningitis.

Croup

Most children who present with acute onset of barky cough, stridor, and chest-wall indrawing have croup. A careful history and physical examination is the best method to confirm the diagnosis and to rule out potentially serious alternative disorders such as bacterial tracheitis and other rare causes of upper-airway obstruction. Epinephrine delivered via a nebuliser is effective for temporary relief of symptoms of airway obstruction. Corticosteroids are the mainstay of treatment, and benefit is seen in children with all levels of severity of croup, including mild cases.

WITHDRAWN: Glucocorticoids for acute viral bronchiolitis in infants and young children

BACKGROUND

Systemic glucocorticoids have been widely prescribed for use in infants and young children with acute viral bronchiolitis but the actual benefit of this intervention requires clarification.

OBJECTIVES

To systematically review the evidence on the effectiveness of systemic glucocorticoids for the treatment of infants and young children with acute viral bronchiolitis.

SEARCH STRATEGY

Multiple strategies were incorporated to maximize identification of suitable studies. The following databases were searched: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2003); MEDLINE (January 1966 to September 2003); Current Contents (1998 to 2000); EMBASE (January 1990 to September 2003); and Sci Search. Handsearches through cited references and contacts with experts were also used.

SELECTION CRITERIA

Only randomised controlled trials (RCT) were eligible for inclusion. Studies were included if participants were diagnosed with acute viral bronchiolitis and treated with systemic (oral, intramuscular or intravenous) corticosteroids. Three reviewers independently selected potentially relevant articles. Four reviewers evaluated these studies, determined eligibility and assessed the methodological quality of each RCT.

DATA COLLECTION AND ANALYSIS

The primary outcome of interest was length of hospital stay (LOS). Secondary outcomes were: respiratory rate, haemoglobin oxygen saturation, and hospital admission and revisit rates. Data were extracted independently by the four reviewers and the results compiled and compared. Two reviewers reassessed studies to clarify points of discrepancy in the data extraction and database entry processes. Missing data were requested from the authors or calculated from other data presented in the study report.

MAIN RESULTS

There was complete agreement on the inclusion of 13 trials and the exclusion of five studies. Two main study recruitment groups were identified: a) infants and young children within the first 48 hours of hospitalisation (10 trials), and b) outpatient infants and young children who were randomised from the emergency department and who may nor may not have required hospital admission (three trials).A total of 1,198 children aged 0 to 30 months were treated with the equivalent of 0.5 to 10 mg/kg of systemic prednisone for two to seven days. Outcomes of interest were not measured in each RCT. In the pooled analysis of seven trials, there was a decrease in LOS in treated children of 0.38 days (95% confidence interval (CI) -0.81 to 0.05), indicating no significant difference between treatment groups. In the pooled analysis of eight trials, the day three clinical score measured: a standard mean difference (SMD) of -0.20 (95% CI -0.73 to 0.32), indicating no difference between treatment groups. Subgroup analyses for base LOS and clinical score outcomes were performed on infants who were a) less than 12 months of age, b) all respiratory syncytial virus (RSV) positive, c) treated with less than 6 mg/kg of prednisone equivalent throughout the illness and d) first-time wheezers. These were limited by the small number of studies in each subgroup. Hospital admission rates were examined in three trials and no difference was seen between treatment groups (odds ratio (OR) 1.05 (95% CI 0.23 to 4.87). Readmission rates were reported in six studies; with no significant differences between treatment groups. Hospital revisit rates were reported in three studies, with a significant difference between treatment groups reported in one study only. The respiratory rate and haemoglobin oxygen saturation were reported descriptively in six RCTs; no differences were found between groups. Co-interventions (oxygen, supportive fluids and bronchodilators) were used similarly between treatment groups in all RCTs.

AUTHORS' CONCLUSIONS

No benefits were found in either LOS or clinical score in infants and young children treated with systemic glucocorticoids as compared to placebo. There were no differences in these outcomes between treatment groups; either in the pooled analysis or in any of the sub analyses. Among the three studies evaluating hospital admission rates following the initial hospital visit there was no difference between treatment groups. There were no differences found in respiratory rate, haemoglobin oxygen saturation, hospital revisit or readmission rates. Subgroup analyses were significantly limited by the low number of studies in each comparison. Marked study heterogeneity and occasionally conflicting direction of benefit between trials suggests that these results should be interpreted with caution. Specific data on the harm of corticosteroid therapy in this patient population are lacking. Available evidence suggests that corticosteroid therapy is not of benefit in this patient group.

Nitrogen and oxygen molecules in meningitis-associated labyrinthitis and hearing impairment

Pneumococcal meningitis remains a serious disease with a case fatality rate of 15%-25%. Furthermore, long-term residues affect up to 50% of survivors. One of the most frequent sequelae is sensorineural hearing loss, which occurs in 26% of survivors of pneumococcal meningitis. Unfortunately, sufficient treatment regimens are still missing. New insights into the pathology and pathophysiology of meningitis-associated hearing loss have come from animal models of bacterial meningitis. Most likely, bacteria reach the cochlea through the cochlear aquaeduct. Once arrived in the perilymphatic spaces, they induce a severe suppurative labyrinthitis. The blood-labyrinth barrier breaks, hair cells are damaged, and neurons in the spiral ganglion undergo cell death, leading to meningitis-associated hearing loss. Reactive oxygen and nitrogen species, in particular peroxynitrite, seem to be among the crucial mediators of cochlear damage and hearing loss during meningitis. In our rat model of pneumococcal meningitis, adjunctive therapy with the antioxidants and peroxynitrite scavengers Mn(III)tetrakis(4-bencoic acid)-porphyrin (MnTBAP) and N-Acetyl-L-Cystein (NAC) significantly attenuated acute and long-term hearing loss. In several other animal studies of pneumococcal meningitis, adjunctive antioxidant therapy also protected infected animals from intracranial complications. Therefore, the use of antioxidants seems to be a promising future treatment option in pneumococcal meningitis.

A history of adjunctive glucocorticoid treatment for pediatric sepsis: moving beyond steroid pulp fiction toward evidence-based medicine

OBJECTIVES

To review the history of clinical use of corticosteroids with particular reference to adjunctive therapy for severe pediatric sepsis and, in this context, to provide an overview of what is known, what is not known, and what research questions are particularly relevant at this time.

DATA SOURCE

Literature review using PubMed, cross-referenced article citations, and the Internet.

CONCLUSIONS

The history of corticosteroid use in clinical medicine has been colorful, noisy, and always controversial. Therapeutic corticosteroid indications that initially seemed rational have frequently been refuted on closer, rigorous clinical trial inspection. Although it may be prudent to provide stress-dose steroids to children with septic shock who are clinically at risk for adrenal insufficiency (chronic or recent steroid use, purpura fulminans, etomidate or ketoconazole administration, hypothalamic, pituitary, adrenal disease), the safety and efficacy of stress-dose steroids as general adjunctive therapy for pediatric septic shock have not been established. Glucocorticoid administration does add potential risk to critically ill children. In particular, although adjunctive corticosteroids may hasten resolution of unstable hemodynamics in septic shock, this may occur at the metabolic cost of hyperglycemia. Clinical practice that fosters innovative therapy (off-label use) over research probably represents bad medical and social policy. Accordingly, pediatric critical care researchers have a responsibility to generate pediatric-specific evidence-based medicine for adjunctive corticosteroid therapy for severe sepsis in children.

Adjuvant glycerol and/or dexamethasone to improve the outcomes of childhood bacterial meningitis: a prospective, randomized, double-blind, placebo-controlled trial

BACKGROUND

Despite favorable meta-analyses, no study involving third-generation cephalosporins for the treatment of childhood bacterial meningitis has documented a benefit of adjuvant dexamethasone therapy if the outcomes are examined individually.

METHODS

We conducted a prospective, randomized, double-blind trial comparing adjuvant dexamethasone or glycerol with placebo in children aged from 2 months through 16 years in Latin America. Ceftriaxone was administered to all children; children were randomized to also receive dexamethasone intravenously, glycerol orally, both agents, or neither agent. Primary end points were death, severe neurological sequelae, or deafness, with the first 2 end points forming a composite end point. A subgroup analysis for Haemophilus influenzae type b meningitis was undertaken. Intention-to-treat analysis was performed using binary logistic regression models.

RESULTS

H. influenzae type b, pneumococci, and meningococci were the main agents found among 654 patients; dexamethasone was given to 166, dexamethasone and glycerol were given to 159, glycerol was given to 166, and placebo was given to 163. No adjuvant therapy significantly affected death or deafness. In contrast, glycerol and dexamethasone plus glycerol reduced severe neurological sequelae, compared with placebo; the odds ratios were 0.31 (95% confidence interval [95% CI], 0.13-0.76; P=.010) and 0.39 (95% CI, 0.17-0.93; P=.033), respectively. For neurological sequelae and death, the odds ratios were 0.44 (95% CI, 0.25-0.76; P=.003) and 0.55 (95% CI, 0.32-0.93; P=.027), respectively. Dexamethasone therapy prevented deafness in patients with H. influenzae type b meningitis only if patients were divided grossly into dexamethasone recipients and nonrecipients and if timing between dexamethasone and ceftriaxone administration was not taken into account (odds ratio, 0.27; 95% CI, 0.09-0.77; P=.014).

CONCLUSION

Oral glycerol therapy prevents severe neurological sequelae in patients with childhood meningitis. Safety, availability, low cost, and oral administration also add to its usefulness, especially in resource-limited settings.

Limited efficacy of adjuvant therapy with dexamethasone in preventing hearing loss due to experimental pneumococcal meningitis in the infant rat

Sensorineural hearing loss (SNHL) is the most common sequel of bacterial meningitis (BM) and is observed in up to 30% of survivors when the disease is caused by Streptococcus pneumoniae. BM is the single most important origin of acquired SNHL in childhood. Anti-inflammatory dexamethasone holds promises as potential adjuvant therapy to prevent SNHL associated with BM. However, in infant rats, pneumococcal meningitis (PM) increased auditory brainstem response (ABR) thresholds [mean difference = 54 decibels sound pressure level (dB SPL)], measured 3 wk after infection, irrespective to treatment with ceftriaxone plus dexamethasone or ceftriaxone plus saline (p < 0.005 compared with mock-infected controls). Moreover, dexamethasone did not attenuate short- and long-term histomorphologic correlates of SNHL. At 24 h after infection, blood-labyrinth barrier (BLB) permeability was significantly increased in infected animals of both treatment groups compared with controls. Three weeks after the infection, the averaged number of type I neurons per square millimeter of the Rosenthal's canal dropped from 0.3019 +/- 0.0252 in controls to 0.2227 +/- 0.0635 in infected animals receiving saline (p < 0.0005). Dexamethasone was not more effective than saline in preventing neuron loss (0.2462 +/- 0.0399; p > 0.05). These results suggest that more efficient adjuvant therapies are needed to prevent SNHL associated with pediatric PM.

Efficacy of Corticosteroids in the Treatment of Community-Acquired Pneumonia Requiring Hospitalization

BACKGROUND

Recent studies suggested that administration of corticosteroids may improve clinical outcomes in patients with severe pneumonia.

OBJECTIVES

The aim of this study was to assess the effectiveness of corticosteroids as an adjunctive therapy in community-acquired pneumonia (CAP) requiring hospitalization.

DESIGN AND SETTING

An open label, prospective, randomized control study was conducted from September 2003 to February 2004 in a community general hospital in Japan.

PATIENTS

Thirty-one adult CAP patients who required hospitalization were enrolled.

MEASUREMENTS AND RESULTS

Fifteen patients received 40 mg of prednisolone intravenously for 3 days (steroid group). Sixteen patients did not receive prednisolone (control group). Both groups were also evaluated for their adrenal function. The primary endpoint was length of hospital stay. Secondary endpoints were duration of intravenous (IV) antibiotics and time required to stabilize vital signs. Both groups demonstrated similar baseline characteristics and length of hospital stay, and yet a shorter duration of IV antibiotics was observed in the steroid group (p < 0.05). In addition, vital signs were stabilized earlier in the steroid group (p < 0.05). These differences were more prominent in the moderate-severe subgroup but not as significant in the mild-moderate subgroup. The prevalence of relative adrenal insufficiency (RAI) in both groups was high (43%), yet there was no difference in baseline characteristics between patients, with or without RAI. In multiple regression models, RAI seemed to have no influence on clinical courses.

CONCLUSIONS

In moderate-severe CAP, administration of corticosteroids promotes resolution of clinical symptoms and reduces the duration of intravenous antibiotic therapy.

Otoprotective Effects of Dexamethasone in the Management of Pneumococcal Meningitis: an Animal Study

OBJECTIVE

To determine whether treating pneumococcal meningitis with a combined antibiotic and steroid regime will prevent cochlear damage, a common pneumococcal meningitis side effect.

STUDY DESIGN

Prospective animal study.

METHODS

Gerbils were randomly assigned to three experimental groups. Animals in group 1 received intrathecal saline injections. Animals in groups 2 and 3 received intrathecal injections of Streptococcus pneumoniae to induce meningitis. Group 2 was treated for 7 days with intraperitoneal penicillin injections (48,000 units). Animals from group 3 received intraperitoneal dexamethasone (0.5 mg/kg) injections for 4 days in addition to 7 days of intraperitoneal penicillin. Three months after the meningitis was induced, the animals' cochlear functions were determined using auditory brainstem responses (ABRs). After measuring cochlear function, the animals were sacrificed for cochlear histopathology. Spiral ganglion cell densities at Rosenthal's canal were determined.

RESULTS

ABR thresholds were significantly elevated in animals from group 2 when compared with the animals in groups 1 and 3 (P < .05). ABR thresholds for animals from group 3 and group 1 were similar (P > .05). Damage of cochlear structures was detected in animals from group 2. The degree of the damage varied: one animal in group 2 had no identifiable hair cells and pillar cells and showed damage of the tectorial membrane. Spiral ganglion density in the basal turn was significantly less in animals from group 2 when compared with controls (P < .05). Although spiral ganglion cell density was less in the dexamethasone-treated group (group 3) when compared with group 1 (control group), but greater than observed in animals treated with antibiotics only (group 2), the differences were statistically not significant (P > .5). Nuclear diameters of the spiral ganglion cells decreased on average from 7.24 +/- 0.48 microm (group 1) to 6.28 +/- 0.76 microm (group 3, animals that received dexamethasone) to 5.57 +/- 0.82 microm (group 2, animals that received antibiotics only). Differences were significant (P < .05). Differences in stria vascularis thickness were not significant among the animals.

CONCLUSION

Dexamethasone has a protective effect on the cochlea when given together with antibiotics in the treatment of pneumococcal meningitis.

Fibronectin is elevated in the cerebrospinal fluid of patients suffering from bacterial meningitis and enhances inflammation caused by bacterial products in primary mouse microglial cell cultures

Toll-like receptors (TLR) play a key role in the recognition of pathogenic organisms. Fibronectin, an extracellular matrix protein, is considered a potent stimulator of the innate immune system through TLR4. In bacterial meningitis, several extracellular matrix proteins and bacterial compounds are elevated in the CSF. For this reason, we hypothesized that these molecules may jointly stimulate the innate immune system and increase neuronal damage in bacterial meningitis. Concentrations of fibronectin were elevated in the CSF of patients suffering from bacterial meningitis, but not in patients with multiple sclerosis, when compared with control patients without CSF abnormalities. In primary cultures of mouse microglial cells, co-administration of fibronectin at concentrations occurring in the CSF in bacterial meningitis (10 microg/mL) with defined TLR agonists [lipopolysaccharide (TLR4), the synthetic lipopeptide tripalmytoyl-cysteinyl-seryl-(lysyl)3-lysine (TLR2) and single-stranded unmethylated cytosine-guanosine oligodesoxynucleotide (TLR9)] led to an additive release of nitric oxide and tumor necrosis factor-alpha when compared with the release elicited by either compound alone. In conclusion, the inflammatory reaction to bacterial compounds can be aggravated by endogenous fibronectin at elevated levels during bacterial CNS infections. This additive or synergistic effect may contribute to neuronal damage during bacterial meningitis.

Cerebral vasospasm in shunt infection

OBJECTIVE

In bacterial shunt infection, CNS inflammation is a frequently observed complication that may cause vascular complications including vasospasms. Here, we describe the first patient with shunt infection-induced cerebral vasospasms.

METHODS

A 35 year old woman with a ventriculoperitoneal shunt that was implanted years before developed facial nerve palsy and somnolence one week before admission to the hospital.

RESULTS

After admission, the shunt was removed, and an external ventricular drainage was inserted. Microbiological analyses revealed coagulase-negative Staphylococcus on abdominal and cranial catheters. Follow-up NMR showed infarctions. Transcranial doppler sonography and cerebral arteriography revealed severe generalized cerebral vasospasms. Inspite of triple-H therapy and intraarterial spasmolysis, bilateral anterior and media artery infarction evolved. The patient was dismissed in a vegetative state.

CONCLUSIONS

This case shows that severe cerebral vasospasms are a serious complication in patients with bacterial shunt infection that should be considered in patients, that don't improve following adequate antibiotic treatment.

Mortalité par méningites à pneumocoque chez l'enfant. Facteurs pronostiques à propos d'une série de 73 observations

OBJECTIVE

Despite advances in antibiotic therapy strategies and pediatric intensive care, prognosis of Streptococcus pneumoniae meningitis remains very poor. To determine the factors associated with hospital mortality of children with pneumococcal meningitis.

METHODS

We conducted a retrospective study of 73 cases of childhood pneumococcal meningitis admitted in 4 teaching hospitals in the center of Tunisia during a 8-year period (1995-2002).

RESULTS

Hospital mortality was 13.7% (10 of 71 patients), and neurologic sequela were observed in 34.5% of survivors. Based on univariable analysis, five variables were associated with the outcome: Pediatric Risk of Mortality score (p < 0.001), coma (p=0.0009), use of mechanical ventilation (p=0.0001), convulsions (p = 0.0449), and shock (p=0.0085). In multivariable analysis, only 2 factors were independently associated with in-hospital mortality: Pediatric Risk of Mortality score and the use of mechanical ventilation. 11.8% of pneumococcal isolates were intermediate and resistant to penicillin. Non-susceptible pneumococcus strains to penicillin and the use of steroids were not associated significantly with the mortality rate.

CONCLUSIONS

Pneumococcal meningitis remains a devastating childhood disease. Two variables were independently associated with the in-hospital death in our series (high Pediatric Risk of Mortality score, and the use of mechanical ventilation). According to these data we may recommend the inclusion of vaccination against streptococcus pneumonia in the children's immunization program in Tunisia.