The beneficial effects of early dexamethasone administration in infants and children with bacterial meningitis

Clindamycin is neuroprotective in experimental Streptococcus pneumoniae meningitis compared with ceftriaxone

In animal models of Streptococcus pneumoniae meningitis, rifampin is neuroprotective in comparison to ceftriaxone. So far it is not clear whether this can be generalized for other protein synthesis-inhibiting antimicrobial agents. We examined the effects of the bactericidal protein synthesis-inhibiting clindamycin (n = 12) on the release of proinflammatory bacterial components, the formation of neurotoxic compounds and neuronal injury compared with the standard therapy with ceftriaxone (n = 12) in a rabbit model of pneumococcal meningitis. Analysis of the CSF and histological evaluation were combined with microdialysis from the hippocampal formation and the neocortex. Compared with ceftriaxone, clindamycin reduced the release of lipoteichoic acids from the bacteria (p = 0.004) into the CSF and the CSF leucocyte count (p = 0.011). This led to lower extracellular concentrations of hydroxyl radicals (p = 0.034) and glutamate (p = 0.016) in the hippocampal formation and a subsequent reduction of extracellular glycerol levels (p = 0.018) and neuronal apoptosis in the dentate gyrus (p = 0.008). The present data document beneficial effects of clindamycin compared with ceftriaxone on various parameters linked with the pathophysiology of pneumococcal meningitis and development of neuronal injury. This study suggests neuroprotection to be a group effect of bactericidal protein synthesis-inhibiting antimicrobial agents compared with the standard therapy with beta-lactam antibiotics in meningitis.

Acute Bacterial Meningitis in Children

Despite advances in recent decades in management, including new and effective antimicrobials, children with bacterial meningitis still incur significant morbidity and mortality. Pathophysiologic processes including colonization and migration of the bacteria to blood, seeding of the meninges, and meningeal and brain inflammation have been largely elucidated, but more specific knowledge could lead to new effective therapies. Outside of the neonatal period, the most common causative organisms have been Haemophilus influenzae, Streptococcus pneumoniae, and Neisseria meningitidis. However, conjugate vaccines, especially the H influenzae type b preparation, have contributed significantly to steep declines in the incidence of meningitis. Optimal management consists of rapid diagnosis and administration of bactericidal antibiotics with properties allowing adequate penetration of the inflamed blood-brain barrier. Recently, development of microbial resistance has resulted in changes to recommended empiric antibiotic regimens. Novel therapies are under investigation; however, until controlled trials can be conducted, these therapies cannot be recommended.

Seizures complicating infantile and childhood bacterial meningitis

In this study, 116 patients, at least 1 month of age but younger than 5 years, were identified with culture-proven bacterial meningitis. A comparison was made between the clinical data of the patients with and without seizures during hospitalization. Seizures during acute bacterial meningitis accounted for 47% (55/116) of the episodes. Time interval between the onset of bacterial meningitis and that of seizures was 1 to 20 days (mean, 4 days). Twelve of these 55 patients had one or more afebrile seizures after completing the treatment. At follow-up of at least 1 year after completing treatment, 26 patients had good outcomes, whereas the other 29 patients had poor outcomes. A strong correlation between the findings of abnormalities through neuroimaging and the occurrence of seizures during hospitalization was observed. The long-term outcomes of patients with infantile and childhood bacterial meningitis, who had seizures during the acute phase of bacterial meningitis, were worse than the outcomes of those who did not have such seizures. No child developed late seizures unless there were acute seizures. Factors associated with seizures during acute bacterial meningitis include disturbed consciousness on admission, abnormal neuroimaging findings, and low glucose and high concentration of total proteins in cerebrospinal fluid.

Brainstem and cranial nerve abnormalities: listeriosis, otitis media/interna, and pituitary abscess syndrome

This article reviews three disorders associated with multiple asymmetric cranial nerve deficits in ruminants: encephalitic listeriosis,otitis media/interna, and pituitary abscess syndrome. Emphasis is placed on encephalitic listeriosis, an infectious disease of the brainstem and cranial nerves caused by Listeria monocytogenes. The epidemiology, pathophysiology, clinical manifestations, diagnosis,and treatment of encephalitic listeriosis are reviewed, and differences between cattle and small ruminants are noted. Physical and neurologic examination findings that distinguish otitis media/interna and pituitary abscess syndrome from encephalitic listeriosis are highlighted.

Sequelae from meningococcal meningitis in children: a critical analysis of dexamethasone therapy

OBJECTIVE: To evaluate the effectiveness of dexamethasone as an adjunctive therapy to antibiotics in children with meningococcal meningitis. METHOD: A total of 81 children diagnosed with meningococcal meningitis hospitalized in sequence were studied at the University Hospital of São Paulo University, with the objective of evaluating the presence of sequelae in four different groups of patients, following the administration of dexamethasone: Group I - 25 patients who received the first dose at least 10 minutes before the introduction of the antibiotic therapy; Group II - 19 patients who received the corticosteroid concomitantly; Group III - 14 patients for which the dexamethasone was administered after beginning the antibiotic scheme; Group IV - 23 patients that did not receive dexamethasone. The groups were evaluated for homogeneity through the prognostic indexes and clinical and laboratory characteristics, based on the records obtained at hospitalization. RESULTS: Some degree of sequelae occurred in 16 (26.22%) of the survivors and 23 patients (28.39%) coursed with sequelae or died. The mean period of neurological attendance was 36.97 months and neurological alterations were detected in 16.17% of the patients. No significant difference was found between the four groups. There was also no statistical difference in the comparison of the neurological sequelae in the children from group IV with the children of groups I and II or even with groups I, II and III analyzed as a whole. The presence of hearing loss occurred in 11.11% of the patients, again there was no significant difference between the four groups. Psychological evaluation was performed using the WPSSI and WISC tests. A mild mental disability was detected in one patient from group I and another in group III. The overall analysis of the sequelae (neurological, auditory and intellectual level) also did not demonstrate any significant difference between the four groups. Comparing the children from groups I and II together and also groups I, II and III as a whole with the children in group IV also failed to detect a significant difference arising from the use or nonuse of the corticosteroid. CONCLUSION: Dexamethasone was not proven to be effective in decreasing the number of sequelae among patients with meningococcal meningitis.

Invasive Haemophilus influenzae type b infections in children in Paraguay

BACKGROUND

In Paraguay, as in most Latin American countries, data on the epidemiology and clinical characteristics of Haemophilus influenzae type b (Hib) diseases are scarce and incomplete.

METHODS

To address this issue, we performed a retrospective analysis of 102 patients admitted to the Instituto de Medicina Tropical, a referral hospital in Asunción, Paraguay, between January 1991 and September 1995 with diagnosis of invasive Hib infection. This study included patients 15 years of age and under-identified with positive cultures for Hib in blood, cerebrospinal fluid, or other sterile body fluids.

RESULTS

Eighty three (81%) patients presented with meningitis as principal focus of infection with median age of 9 months. Forty five (54%) patients with Hib meningitis were <12 months of age and 20 (24% of total cases) were <6 months of age. Overall mortality rate of meningitis was 13%. Of 11 patients who died, 10 (91%) were <12 months of age (p <0.02). Risk for mortality was correlated with presence of coma during admission (p <0.007) and CSF glucose level of <10 mg/dL (p <0.05). Severe sequelae such as bilateral hearing loss, hydrocephalus, and mental retardation were observed in 39% (28/72) of surviving patients, of whom 18 (51%) patients were <12 months of age (p <0.02). Thirty percent of isolated strains of Hib were resistant to ampicillin, 20% were resistant to chloramphenicol, and 10% to both drugs.

CONCLUSIONS

This information provides evidence concerning the importance of continued support for Hib vaccine supplies in immunization programs in countries with limited resources such as Paraguay.

Neuro-cognitive impairment following acquired central nervous system infections in childhood: a systematic review

The morbid consequences of central nervous system (CNS) infections are often overlooked in the face of high mortality rates. However, neurological impairments not only affect the child's development and future prospects but also place an economic and social burden on communities and countries that often have few resources to deal with such problems. We conducted a systematic review to investigate the occurrence and pattern of persisting neurological impairment after common CNS infections. A comprehensive search of MEDLINE, EMBASE and PsycINFO databases, supplemented by hand-searches of key journals, resulted in forty-six eligible studies, five of which gave information on the spectrum of developmental domains. Despite the lack of comprehensive, methodologically-sound studies, the results show that postinfectious neurological impairment persists, most commonly in cognition and motor functions. Deficits include more subtle problems, which can be difficult to detect on gross neurological assessment but may still be deleterious to the child's social and educational functioning. Higher morbidity for similar mortality in acute bacterial meningitis compared with cerebral malaria in the epidemiological data may suggest future research directions for clinical research to devise more effective interventions.

Adjunctive dexamethasone treatment in acute bacterial meningitis

The initiation of antibiotic treatment on suspicion of bacterial meningitis is important, but it is not enough to improve the prognosis for patients, especially those with pneumococcal meningitis. The mortality and morbidity of pneumococcal meningitis are still devastating, and results of a recent randomised trial have shown evidence in favour of dexamethasone treatment given before or with the first antibiotic dose. Adjuvant dexamethasone is unequivocally recommended in children and adults with haemophilus meningitis or pneumococcal meningitis. The benefit of adjunctive dexamethasone is likely to be greatest in patients who are otherwise healthy and present early with acute bacterial meningitis. Dexamethasone is not currently recommended for the treatment of gram-negative bacillary meningitis and neonatal meningitis. Dexamethasone, before or with the first dose of antibiotic, is likely to be one of the most significant practice changes that will benefit many adults and children with common types of acute bacterial meningitis and has been of proven value in the developed world.

Sensorineural Hearing Loss in Postmeningitic Children

OBJECTIVE

To establish the proportion of children who develop sensorineural hearing loss after bacterial meningitis and to correlate such loss with patient factors.

STUDY DESIGN

Retrospective case review.

SETTING

McMaster University Children's Hospital, a tertiary referral center.

PATIENTS

Children between the ages of 1 day and 18 years admitted to McMaster University Children's Hospital with a confirmed diagnosis of bacterial meningitis between January 1, 1991 and December 30, 2000.

INTERVENTIONS

Audiological assessment including auditory brainstem responses and cortical electric-response audiometry or standard audiometry.

MAIN OUTCOME MEASURES

The nature of sensorineural hearing loss was assessed according to the degree (mild to profound) and course (transient versus permanent). Correlations between sensorineural hearing loss and the patient's age, sex, duration of illness before admission, use of dexamethasone, concurrent neurologic complications, and types of pathogens were evaluated. Patterns of inpatient and outpatient audiological assessment were determined.

RESULTS

Seventy-nine children had confirmed bacterial meningitis. Streptococcus pneumoniae accounted for 36.7 percent of all cases, followed-up by Neisseria meningitides (16.5%), group B Streptococcus (15.2%), and Hemophilus influenzae (13.9%). Sixty-eight (86.1%) children underwent hearing assessment, either as inpatients or after discharge. Of the remaining 11 (13.9%) in whom audiological evaluation could not be confirmed, only two made mention of a referral. As such, a nonreferral rate of 11.4 percent was identified. Abnormal auditory brainstem response findings were present in 22 cases (32.3%), with 11 cases (13.9%) of permanent sensorineural hearing loss identified. A statistically significant association between sensorineural hearing loss and Streptococcus pneumoniae was found (p < 0.001). No association between age, sex, duration of illness before admission, use of dexamethasone, and number of concurrent neurologic complications could be established.

CONCLUSIONS

In our series, 11 children (13.9%) experienced permanent sensorineural hearing loss, consistent with previously reported rates of 5 to 35 percent within the pediatric population. Since introduction of the Hemophilus influenzae type B vaccine, Streptococcus pneumoniae has emerged as the dominant causative organism of bacterial meningitis in children. Our study additionally confirms the role of Streptococcus pneumoniae as a precipitant of sensorineural hearing loss (p < 0.001). Audiological assessment in our series (86.1%) exceeds most of the screening rates previously reported in the literature. Because of compliance problems with outpatient audiological assessment and because early identification and expedient amplification lead to better academic and language outcomes, routine inpatient audiological screening of postmeningitic children is advocated.

Cytokine and cellular inflammatory sequence in enteroviral meningitis

OBJECTIVE

To clarify the sequence of cytokines and inflammatory cells in enteroviral meningitis.

METHODS

Cerebrospinal fluid (CSF) was collected from 86 patients who received a diagnosis of enteroviral meningitis after detection of the enteroviral genome in the CSF using polymerase chain reaction. Twenty-one of 86 patients had repeated lumbar punctures. Cytokine concentrations were measured acutely and in 32 samples collected during recovery.

RESULTS

The proinflammatory cytokines (interleukin [IL]-6, IL-8, and interferon-gamma) were detected at significantly higher concentrations during the acute phase when enteroviral genomes were present. Proinflammatory cytokines decreased to normal levels in the recovery phase when enteroviral genomes disappeared. Anti-inflammatory concentrations (IL-10 and transforming growth factor-beta1) were significantly higher in the recovery phase than in the acute phase. Of the 86 CSF samples collected in the acute phase, 11 had no pleocytosis (<10 white blood cells/mm(3)). In 7 of those 11 CSF samples, IL-6 and IL-8 levels were as high as those in the 75 samples with pleocytosis (>or=10 white blood cells/mm(3)). Seven patients were considered to be in the initial stage of their illness when production of proinflammatory cytokines were high but leukocytes had not yet infiltrated the cerebrospinal cavity.

CONCLUSIONS

The inflammatory process observed in human enteroviral meningitis is comparable with that observed in animal models: 1) infection induces proinflammatory cytokine production, followed by infiltration of white blood cells into the infected area, and 2) inflammation is terminated by the anti-inflammatory cytokines that are produced when pathogens are eliminated.

A randomized, placebo-controlled trial of the effect of antihistamine or corticosteroid treatment in acute otitis media

OBJECTIVES

To determine whether the adjunctive drugs antihistamine and corticosteroid improve immediate and long-term outcomes of acute otitis media (AOM).

STUDY DESIGN

Children with AOM (3 mos-6 y) were enrolled in a randomized, double-blind, placebo-controlled trial. All 179 children received one dose of intramuscular ceftriaxone and were assigned to receive either chlorpheniramine maleate (0.35 mg/kg/d) and/or prednisolone (2 mg/kg/day) or placebo for 5 days. Main outcome measures were rate of treatment failure during the first 2 weeks, duration of middle ear effusion, and rate of recurrences of AOM to 6 months.

RESULTS

Clinical outcomes and recurrence rates did not differ significantly with treatment. Children who received antihistamine alone had significantly longer duration of middle ear effusion (median, 73 days) than subjects in other treatment groups (median, 23 to 36 days, P=.04). Temporary normalization of tympanometric findings on day 5 occurred more frequently in the corticosteroid-treated group (P=.04).

CONCLUSIONS

Five-day treatment with antihistamine or corticosteroid, in addition to antibiotic, did not improve AOM outcomes. Antihistamine use during an acute episode of OM should be avoided, since the drug may prolong the duration of middle ear effusion. The efficacy of 7- to 10-day treatment of AOM with corticosteroid, in addition to antibiotic, deserves further investigation.

Treatment of meningococcal infection

Aggressive early treatment of meningococcal disease can reduce mortality. This relies on prompt recognition and treatment of the complications of septicaemia and meningitis, appropriate ongoing intensive care where necessary, and adequate management of multiple organ failure. Most children with meningococcal disease survive intact, but long term sequelae are increasingly recognised and make follow up essential. New treatments continue to be evaluated, but none has so far proven to be effective in further reducing morbidity or mortality. Simple, timely therapeutic manoeuvres may greatly improve the prospects for survival.

Bacterial meningitis in children

This review comprises aspects of the epidemiology, microbiology, pathophysiology, clinical manifestations, diagnosis, management, prognosis, and prevention of bacterial meningitis, with emphasis on the paediatric population. The beginning of this millennium has witnessed the virtual disappearance of Haemophilus invasive disease in some countries, emergence of pneumococcal strains that are resistant to multiple antibiotics, isolation of pneumococci with tolerance to vancomycin, outbreaks and clusters of meningococcal meningitis in several geographical areas, and intense research in development of effective conjugate pneumococcal and meningococcal vaccines. Bacterial meningitis has become an uncommon disease in the developed world. Unfortunately, because of limited economic resources and poor living conditions, many developing countries are still affected by the devastating consequences of this life-threatening systemic infection. Basic and clinical research is needed to discover new antimicrobial and anti-inflammatory agents to improve outcome from disease. Novel strategies are needed to distribute and implement effective vaccines worldwide to prevent bacterial meningitis.

The hypothalamic-pituitary-adrenal axis and low-dose glucocorticoids in the treatment of septic shock

Severe sepsis is the leading cause of death among patients in intensive care units. Recombinant activated protein C is the only substance known to directly improve morbidity and mortality. Adrenal insufficiency occurs frequently in patients with sepsis and is associated with poor outcome. Although high-dose glucocorticoids have not positively affected clinical outcome, small trials in which low-dose glucocorticoids were administered to patients with septic shock and relative adrenal insufficiency have shown decreased mortality. The main effect of glucocorticoids in low-doses apparently is exerted through correction of suppression of the hypothalamic-pituitary-adrenal axis. However, the therapeutic benefits of glucocorticoids may be related to their antiinflammatory properties and endogenous catecholamine-enhancing effects.

Dexamethasone or interleukin-10 blocks interleukin-1beta-induced uterine contractions in pregnant rhesus monkeys

OBJECTIVE

The purpose of this study was to determine whether treatment with the immune modulators dexamethasone or interleukin-10 prevents interleukin-1beta-induced uterine contractions in a nonhuman primate model.

STUDY DESIGN

Thirteen chronically instrumented rhesus monkeys at 135 +/- 1 days of gestation (term, 167 days) received one of three interventions: (1) intra-amniotic interleukin-1beta (10 microg) infusion with maternal dexamethasone (1 mg/kg) intravenously every 6 hours for 1 day before interleukin-1beta and for 2 days thereafter (n = 4), (2) intra-amniotic interleukin-1beta infusion with maternal interleukin-10 (25 microg/kg) given intravenously and 100 microg interleukin-10 given intra-amniotically before the interleukin-1beta and continued every 8 hours for 3 days (n = 5), and (3) intra-amniotic interleukin-1beta administered alone (n = 5). Uterine activity was monitored continuously and quantified as the hourly contraction area (millimeters of mercury times seconds per hour) in all groups until delivery. Amniotic fluid was sampled for leukocyte counts and assayed for prostaglandins E(2) and F(2)alpha, cytokines interleukin-1beta, interleukin-6, interleukin-8, tumor necrosis factor-alpha, interleukin-10, and interleukin-1 receptor antagonist by specific assays. Maternal and fetal blood were assayed for cortisol, dehydroepiandrosterone sulfate, and estradiol.

RESULTS

Interleukin-1beta infusion in the absence of immune modulators resulted in an increase in uterine activity and amniotic fluid proinflammatory cytokines, prostaglandins, and leukocytes. Dexamethasone and interleukin-10 treatment significantly reduced interleukin-1beta-induced uterine contractility (P <.05) and amniotic fluid prostaglandins (P <.05) but not interleukin-8 or interleukin-1 receptor antagonist. Amniotic fluid interleukin-6 and maternal and fetal cortisol, dehydroepiandrosterone sulfate, and estradiol concentrations were reduced by dexamethasone (P <.05), whereas tumor necrosis factor-alpha levels and leukocyte counts were attenuated by interleukin-10 treatment (P <.05). An inverse relationship was noted between amniotic fluid interleukin-10 concentrations and interleukin-1beta-induced uterine activity (r = -0.74, P <.05).

CONCLUSION

Dexamethasone and interleukin-10 exert similar inhibitory effects on interleukin-1beta-induced uterine activity, which appears to be mediated by a decrease in prostaglandin production. Reduced estrogen biosynthesis or suppression of tumor necrosis factor-alpha and leukocyte migration may contribute to the tocolytic actions of dexamethasone and interleukin-10, respectively. Dexamethasone and interleukin-10 are likely to be useful adjuncts in the treatment of preterm labor that is associated with inflammation or infection.

External hydrocephalus in a dog with suspected bacterial meningoencephalitis

An approximately 12-week-old, male fox terrier was presented for clinical and physical signs consistent with hydrocephalus. Diagnostic evaluation led to a diagnosis of external hydrocephalus and fibrinopurulent meningoencephalitis. Treatment consisted of antibiotics and the placement of a ventriculoperitoneal shunt. The dog improved neurologically and was alive and doing well 1 year following initial presentation. This is the first reported case of external hydrocephalus in the dog. The dog of this report exhibited clinical features consistent with a disorder termed hydrocephalus with periventricular encephalitis.

Meningitis and encephalitis in children. An update

Over the course of the past decade, much has changed on the landscape of meningitis and encephalitis in children. West Nile virus has emerged in the United States as a new etiologic pathogen causing encephalitis. Human herpesvirus-6 has been identified as a cause of encephalitis and febrile seizures. Lymphocytic choriomeningitis virus has been identified as an underrecognized neuroteratogen. The emergence of penicillin-resistant Streptococcus pneumoniae has complicated the treatment of bacterial meningitis, whereas the Haemophilus influenzae vaccine has fundamentally altered the disease's epidemiology. The recognition that much of the neuropathologic change induced by bacterial meningitis is inflammation mediated has paved the way to the demonstration that dexamethasone can substantially improve the outcome of bacterial meningitis in children. Although much progress has been made toward understanding, treating, and preventing these important infections, much remains to be learned.

Transverse myelitis: unusual sequelae of neonatal group B streptococcus disease

Group B streptococcus (GBS) meningitis is one of the most serious infections in the neonatal period. We wish to report a case of transverse myelitis following early onset form of GBS meningitis. The diagnosis and the clinical approach will be discussed.

Controversies in the management of bacterial meningitis

Bacterial meningitis is an important infection of childhood with significant morbidity and mortality, and clinicians are faced with controversies over steroid use and fluid restriction in its initial management because the standard of practice is not clear. A 1999 survey of paediatric infectious diseases specialists demonstrated that only 56% of respondents recommended dexamethasone for Haemophilus influenzae type b meningitis and only 34% recommended dexamethasone for Streptococcus pneumoniae meningitis, despite recommendations for dexamethasone in the 1997 Red Book. The present article illustrates a typical case presentation of bacterial meningitis, and discusses dexamethasone use and fluid restriction. The use of intravenous fluid therapy is also reviewed, based on results from the single prospective randomized clinical trial in this area.

New therapies and vaccines for bacterial meningitis

Acute bacterial meningitis remains an important cause of morbidity and mortality worldwide. There have recently been major advances in the prevention of the major causes of bacterial meningitis following improvements in vaccinology. The success of immunisation against Haemophilus influenzae type b infection is being mirrored with serogroup C conjugated meningococcal vaccine and pneumococcal conjugate vaccine. However, there remain major challenges, notably, serogroup B meningococcal infection and shifts in epidemiology caused by vaccine introduction. In addition, much of the world's population is unvaccinated. Therefore, improvements in management of acute bacterial meningitis are vital. In this review we attempt to summarise important advances in both prevention and treatment of acute bacterial meningitis.

Management of meningitis in children with oral fluid restriction or intravenous fluid at maintenance volumes: a randomised trial

A multi-centre randomised open trial was done to determine whether moderate oral fluid restriction or intravenous fluid at full maintenance volumes would result in a better outcome for children with bacterial meningitis in Papua New Guinea, and what clinical signs could guide fluid management. Children with clinical signs and cerebrospinal fluid suggestive of bacterial meningitis received either breast milk by nasogastric tube at 60% of normal maintenance volumes (n = 172) or intravenous half-normal saline and 5% dextrose at 100% of normal maintenance volumes (n = 174) for the 1st 48 hrs of treatment. An adverse outcome was death or severe neurological sequelae, and a good outcome was defined as intact survival or survival with at worst mild-to-moderate neurological sequelae. The probability of an adverse outcome was 24.7% in the intravenous group and 33.1% in the oral-restricted group, but the difference was not statistically significant (RR 0.75, 0.53-1.04, p = 0.08). Sunken eyes or reduced skin turgor at presentation were risk factors for an adverse outcome (OR 5.70, 95% CI 2.87-11.29) and were most strongly associated with adverse outcome in the fluid-restricted group. Eyelid oedema during treatment was also a risk factor for an adverse outcome (OR 2.54, 95% CI 1.36-4.75) and eyelid oedema was much more common in the intravenous group (26%) than in the restricted group (5%). For many children with bacterial meningitis in less developed countries, moderate fluid restriction is unnecessary and will be harmful; a normal state of hydration should be achieved but over-hydration should be avoided. Giving 100% of normal maintenance fluids, especially with intravenous hypotonic fluid, will lead to oedema in up to one quarter of children with bacterial meningitis. If additional intravenous fluids are required for children with meningitis, an isotonic solution should be used.

Treating meningococcal infections in children

Aggressive early treatment of meningococcal disease in children can reduce mortality. This relies on prompt recognition of septicaemia and meningitis, and treatment of the complications of shock and raised intracranial pressure.

Pneumococcal meningitis in the intensive care unit: prognostic factors of clinical outcome in a series of 80 cases

We have undertaken this retrospective study to determine factors associated with in-hospital mortality and morbidity in 80 adult patients with severe Streptococcus pneumoniae meningitis. Clinical characteristics at admission of patients infected with susceptible (n = 54) and nonsusceptible (n = 17) strains to penicillin G were similar: age: 51 +/- 19 versus 58 +/- 15 yr (p = 0.16); Simplified Acute Severity Score (SAPS II): 39 +/- 14 versus 41 +/- 11 (p = 0.68); and Glasgow Coma Score: 8 +/- 3 versus 9.5 +/- 3 (p = 0.21), respectively. In-hospital mortality was 25% (20/80), with one death among the 17 patients (6%) infected with a nonsusceptible strain (p = 0.03). High-dose dexamethasone was used in 22 cases. By multivariate analysis, three factors were independently associated with death: platelet count < 100 G/L (adjusted odds ratio [aOR] = 32.7; 95% CI = 3.2 to 332.5; p = 0.0032), arterial pH > 7.47 (aOR = 33.1; 95% CI = 3.4 to 319.7; p = 0.0025), and mechanical ventilation (aOR = 48.8; 95% CI = 2.6 to 901.5; p = 0.009). When adjusting for the identified prognostic factors, corticosteroids significantly reduced the risk of death (aOR = 0.069; 95% CI = 0.005 to 0.9; p = 0.048). Only SAPS II was predictive of adverse outcome (death or neurologic deficit). We conclude that in intubated patients with S. pneumoniae meningitis, hyperventilation should be used with caution. Nonsusceptibility to penicillin G is not associated with a worse outcome. High-dose corticosteroids may be beneficial in the most severely ill patients.

Modulation of release of proinflammatory bacterial compounds by antibacterials: potential impact on course of inflammation and outcome in sepsis and meningitis

Several bacterial components (endotoxin, teichoic and lipoteichoic acids, peptidoglycan, DNA, and others) can induce or enhance inflammation and may be directly toxic for eukaryotic cells. Bactericidal antibiotics which inhibit bacterial protein synthesis release smaller quantities of proinflammatory/toxic bacterial compounds than B-lactams and other cell wall-active drugs. Among the B-lactams, compounds binding to penicillin-binding protein 2 (PBP-2) release smaller amounts of bacterial substances than antibacterials inhibiting PBP-3. Generally, high antibiotic concentrations (more than 10 times the MIC) induce the release of fewer bacterial proinflammatory/toxic compounds than concentrations close to the MIC. In several in vitro and in vivo systems, bacteria treated with protein synthesis inhibitors or B-lactams inhibiting PBP-2 induce less inflammation than bacteria treated with PBP-3-active B-lactams. In mouse models of Escherichia coli peritonitis sepsis and of Streptococcus pneumoniae meningitis, lower release of proinflammatory bacterial compounds was associated with reduced mortality. In conclusion, sufficient evidence for the validity of the concept of modulating the release of proinflammatory bacterial compounds by antibacterials has been accumulated in vitro and in animal experiments to justify clinical trials in sepsis and meningitis. A properly conducted study addressing the potential benefit of bacterial protein synthesis inhibitors versus B-lactam antibiotics will require both strict selection and inclusion of a large number of patients. The benefit of this approach should be greatest in patients with a high bacterial load.

Gene profiling reveals unknown enhancing and suppressive actions of glucocorticoids on immune cells

Glucocorticoids continue to be the major immunomodulatory agents used in clinical medicine today. However, their actions as anti-inflammatory and immunosuppressive drugs are both beneficial and deleterious. We analyzed the effect of glucocorticoids on the gene expression profile of peripheral blood mononuclear cells from healthy donors. DNA microarray analysis combined with quantitative TaqMan PCR and flow cytometry revealed that glucocorticoids induced the expression of chemokine, cytokine, and complement family members as well as of newly discovered innate immune-related genes, including scavenger and Toll-like receptors. In contrast, glucocorticoids repressed the expression of adaptive immune-related genes. Simultaneous inhibitory and stimulatory effects of glucocorticoids were found on inflammatory T helper subsets and apoptosis-related gene clusters. In cells activated by T cell receptor cross-linking, glucocorticoids down-regulated the expression of specific genes that were previously up-regulated in resting cells, suggesting a potential new mechanism by which they exert positive and negative effects. Considering the broad and continuously renewed interest in glucocorticoid therapy, the profiles we describe here will be useful in designing more specific and efficient treatment strategies.

Clinical outcomes of neonatal meningitis in very-low birth-weight infants

We sought to describe the clinical presentation and consequences of meningitis among 64 very-low-birth-weight (VLBW <1.5 kg) infants who had 67 culture-proven episodes of meningitis over an 18-year period, 1977 through 1995. Demographic and neonatal descriptors of meningitis and later outcomes were retrospectively examined and neurodevelopmental outcomes of 39 of 45 (87%) meningitis survivors were compared to those of nonmeningitis survivors followed up to 20 months corrected age. Causes of meningitis included coagulase-negative Staphylococcus in 43% of episodes, other gram-positive bacteria in 19%, gram-negative bacteria in 17%, and Candida species in 20% of episodes. Spinal fluid abnormalities were sparse, regardless of etiologic organism. Of 38 nonbloody spinal fluid taps (<1,000 erythrocytes/mm3), 6 had >30 leukocytes/mm3, 5 protein >150 mg/dL%, and 6 glucose <30 mg/dL (1.67 mmol/L). Only 10 infants (26%) had 1 or more of these spinal fluid abnormalities. Meningitis survivors had a higher rate of major neurologic abnormality (41% vs 11%, p<0.001) and subnormal (<70) Mental Development Index (38% vs 14%, p<0.001) than nonmeningitis survivors. Impairment rates did not differ by etiologic organism. The effect of meningitis on neurologic outcome persisted even after controlling for birth weight, intraventricular hemorrhage, chronic lung disease, and social risk factors (odds ratio 2.27 [95% CI 1.02, 5.05]). We conclude that despite a sparsity of abnormal spinal fluid findings, culture-proven neonatal meningitis among VLBW infants has a detrimental effect on neurologic outcome, which persists even after controlling for other risk factors.

Bacterial meningitis in children: critical care needs

Acute bacterial meningitis (ABM) in children is associated with a high rate of acute complications and mortality, particularly in the developing countries. Most of the deaths occur during first 48 hours of hospitalization. Coma, raised intracranial pressure (ICP), seizures, shock have been identified as significant predictors of death and morbidity. This article reviews issues in critical care with reference to our experience of managing 88 children with ABM in PICU. Attention should first be directed toward basic ABCs of life-support. Children with Glasgow Coma Scale (GSC) score < 8 need intubation and supplemental oxygen. Antibiotics should be started, even without LP (contraindicated if focal neuro-deficit, papilledema, or signs of raised ICP). Raised ICP is present in most of patients; GCS < 8 and high blood pressure are good guides. Mannitol (0.25 gm/Kg) should be used in such patients. If there are signs of (impending) herniation short-term hyperventilation is recommended; prolonged hyperventilation (> 1 hour) must be avoided. Any evidence of poor perfusion, hypovolemia and/or hypotension needs aggressive treatment with normal saline boluses and inotropes, if necessary, to maintain normal blood pressure. Empiric fluid restriction is not justified. Seizures may be controlled with intravenous diazepam or lorazepam. Refractory status epilepticus may be treated with continuous diazepam (0.01-0.06) mg/kg/min) or midazolam infusion. Ventilatory support may be needed early for associated pneumonia, poor respiratory effort and/or coma, and occasionally to reduce work of breathing in shock. Provision of critical care to children with ABM may reduce the mortality significantly as experienced by us.

Corticosteroids for septic shock

OBJECTIVE

To gather the data to provide a rationale for using replacement therapy with hydrocortisone in septic shock patients.

DATA SOURCES

The Medline and the Cochrane Library databases.

STUDY SELECTION

Studies in animals and in humans were considered when significant data were available about the mechanisms of action of corticosteroids or about their use in severe sepsis.

DATA SUMMARY

Corticosteroids were the first anti-inflammatory drugs tested in septic patients. Randomized trials clearly showed that a short course of a large dose of anti-inflammatory steroids is ineffective and potentially harmful in patients with severe sepsis. Recent demonstrations of altered hypothalamic-pituitary-adrenal axis response to septic insult have led to a reappraisal of the use of steroids in septic shock. Randomized trials in catecholamine-dependent septic shock patients strongly suggest that replacement therapy with hydrocortisone may alleviate the symptoms of systemic inflammatory response, reduce the duration of shock, and favorably affect survival.

CONCLUSIONS

Current evidence that the therapeutic interest of replacement therapy with corticosteroids increases suggests that low doses of hydrocortisone should be offered to patients with catecholamine-dependent septic shock.

Effect of corticosteroids on nuclear factor-kappaB activation and hemodynamics in late septic shock

OBJECTIVE

To describe the underlying pathophysiologic mechanisms of the effect of corticosteroids in a patient with late septic shock.

DESIGN

Case report.

SETTING

The medical intensive care unit at University Medical Center Utrecht.

PATIENT

An 86-yr-old female patient with late septic shock requiring mechanical ventilation and vasopressive agents.

INTERVENTIONS

Administration of hydrocortisone, 300 mg daily.

MEASUREMENTS AND MAIN RESULTS

Within 3 days of corticosteroid treatment, the patient could be weaned of vasopressive agents and mechanical ventilation. Serum C-reactive protein levels normalized. Nuclear factor-kappaB activation in unstimulated and in vitro lipopolysaccharide-stimulated peripheral blood mononuclear cells decreased to background level within 5 days. Repeated functional tests of the hypothalamic-pituitary-adrenal axis were normal.

CONCLUSION

Our data suggest that the pathophysiologic mechanism behind the clinical effects of supraphysiologic doses of corticosteroids in late septic shock is directly related to the inhibition of nuclear factor-kappaB in peripheral blood mononuclear cells.

Adrenocortical response and cortisone replacement in systemic inflammatory response syndrome

The use of steroids as an adjunct to antimicrobial therapy has been controversial for many decades. Recent reports of the use of steroids in supraphysiological rather than in "industrial" doses in patients with sustained circulatory instability has re-ignited the debate. Anecdotal reports of adrenal insufficiency in septic patients have suggested a relative cortisol deficiency in these patients with poor survival if not given supplementary steroids. The possibility that the hypothalamic pituitary adrenal axis is intimately involved in the pathogenesis of this entity has not previously been highlighted. This review looks at the relationship of sustained cytokine release and the possibility of altering the stress response with progressive loss of adrenocorticotrophic hormone release and subsequent diminution in adequate cortisol levels. The reliance on, and misinterpretation of, the short synacthen test in diagnosing the possibility of this condition is emphasized.

A comparative trial of imipenem versus ceftazidime in the release of endotoxin and cytokine generation in patients with gram-negative urosepsis. Urosepsis Study Group

Evidence from in vitro experiments and animal and human studies indicate that antibiotic therapy may induce the release of endotoxin from the outer membrane of Gram-negative bacteria. Antibiotics that bind preferentially to penicillin-binding protein-2 (PBP-2)--such as imipenem--are associated with little release of endotoxin, while antibiotics that preferentially bind to PBP-3--such as ceftazidime--are associated with far greater release of endotoxin. We conducted a randomized, multicenter, double-blind study comparing imipenem to ceftazidime in patients with urinary tract infections caused by Gram-negative bacilli associated with signs and symptoms of systemic inflammation. A total of 33 patients were randomized to receive either imipenem (n = 14) or ceftazidime (n = 19) for initial treatment for urosepsis. No differences in plasma endotoxin, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) or urine endotoxin, IL-6 or IL-8 levels were found between the two treatment groups within the first 8 h after antibiotic administration. We conclude that, if differences exist with respect to endotoxin release by these two antimicrobial agents, these differences are not readily demonstrable in this clinical study with carefully defined patients with Gram-negative urinary tract infections.

Bacterial meningitis: current controversies in approaches to treatment

Acute bacterial meningitis continues to be a disease with unacceptably high mortality and morbidity rates in both adults and children worldwide, despite advances in antibacterial therapy. Death or permanent disability occurs frequently. The causative organism varies with age, immune function and immunisation status. Infection with Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae type b (Hib) is associated with the majority of cases, with Listeria monocytogenes and Streptococcus agalactiae being more prevalent pathogens at the extremes of age (<3 months or >50 years). Antibacterial resistance is an increasing problem, particularly in pneumococcal bacteria but increasingly in other organisms. The increasing prevalence of resistance of pneumococcus to penicillin and the cephalosporins complicates therapy and may have an important impact on treatment outcome. Increased understanding of the pathophysiology has allowed advances in diagnosis and therapy. The use of adjunctive corticosteroids remains controversial, but is probably beneficial in reducing neurological sequelae in children. In adults the evidence is less clear. Vaccination has virtually eradicated Hib meningitis in some countries. Recent introduction of a conjugate vaccine against serogroup C meningococci in the UK has caused a dramatic reduction in the incidence of invasive disease due to this organism. A 7-valent pneumococcal vaccine promises a similar reduction in the incidence of invasive pneumococcal disease. In the meantime, the emergence of widespread resistance of organisms to antibacterial agents, in particular among the common organisms causing bacterial meningitis, remains the biggest challenge in therapy.

Acute bacterial meningitis in adults. A 12-year review

One hundred three episodes of acute bacterial meningitis in adults hospitalized in Edmonton's 2 largest hospitals from 1985 to 1996 were reviewed. Cases complicating neurosurgery were excluded. Most cases were community-acquired (87%). Twenty-three cases remained culture-negative, and there was no statistical relation between culture negativity and antibiotic pretreatment. Streptococcus pneumoniae was the predominant pathogen (52.5%), but Listeria monocytogenes was the second most common isolate, accounting for 12.5% of culture-positive cases. Compared to non-listerial meningitis, those with listeriosis were more likely to have negative cerebrospinal fluid (CSF) Gram stains (p = 0.07), CSF leukocyte counts < 1,000 cells/mm3 (p < 0.003), and normal CSF glucose (p = 0.006). Bacterial antigen detection was found to be of low sensitivity: 33% in all patients, but only 9% in cases with negative CSF Gram stains. The overall mortality was 18%, with 15 deaths directly attributable to acute meningitis; the case-fatality rates for S. pneumoniae and L. monocytogenes were 24% and 40%, respectively. Mortality was significantly higher among those with seizures (34% versus 7%, respectively; p < 0.001; OR = 17.6). Despite the urgency of acute bacterial meningitis, there were considerable delays in the institution of empiric antibiotics; mortality rates were slightly higher in those who experienced such a delay (16% versus 7% respectively; p = 0.18).

Combined therapy with hypothermia and anticytokine agents in influenza A encephalopathy

Two children with influenza A-related encephalopathy were treated with a combination of mild hypothermia (deep body temperature of the forehead: 35 degrees C) and anticytokine agents (high-dose methylprednisolone and ulinastatin), while receiving amantadine. One of the cases exhibited acute necrotizing encephalopathy on computed tomography (CT). Although no severe complications occurred, correctable hypokalemia and hyperglycemia occurred in both cases. Both patients recovered without any neurological sequelae. Our therapeutic protocol appears to be effective for managing influenza A-related encephalopathy.