Meningococcal septic shock in children: clinical and laboratory features, outcome, and development of a prognostic score

Hematologic Dysfunction Criteria in Critically Ill Children: The PODIUM Consensus Conference

CONTEXT

Studies of organ dysfunction in children are limited by a lack of consensus around organ dysfunction criteria.

OBJECTIVES

To derive evidence-informed, consensus-based criteria for hematologic dysfunction in critically ill children.

DATA SOURCES

Data sources included PubMed and Embase from January 1992 to January 2020.

STUDY SELECTION

Studies were included if they evaluated assessment/scoring tools to screen for hematologic dysfunction and assessed outcomes of mortality, functional status, organ-specific outcomes, or other patient-centered outcomes. Studies of adults or premature infants, animal studies, reviews/commentaries, small case series, and non-English language studies with inability to determine eligibility were excluded.

DATA EXTRACTION

Data were abstracted from each eligible study into a standard data extraction form along with risk of bias assessment.

RESULTS

Twenty-nine studies were included. The systematic review supports the following criteria for hematologic dysfunction: thrombocytopenia (platelet count <100000 cells/µL in patients without hematologic or oncologic diagnosis, platelet count <30000 cells/µL in patients with hematologic or oncologic diagnoses, or platelet count decreased ≥50% from baseline; or leukocyte count <3000 cells/µL; or hemoglobin concentration between 5 and 7 g/dL (nonsevere) or <5 g/dL (severe).

LIMITATIONS

Most studies evaluated pre-specified thresholds of cytopenias. No studies addressed associations between the etiology or progression of cytopenias overtime with outcomes, and no studies evaluated cellular function.

CONCLUSIONS

Hematologic dysfunction, as defined by cytopenia, is a risk factor for poor outcome in critically ill children, although specific threshold values associated with increased mortality are poorly defined by the current literature.

Detectable A Disintegrin and Metalloproteinase With Thrombospondin Motifs-1 in Serum Is Associated With Adverse Outcome in Pediatric Sepsis

Supplemental Digital Content is available in the text.

A Disintegrin and Metalloproteinase with Thrombospondin Motifs-1 is hypothesized to play a role in the pathogenesis of invasive infection, but studies in sepsis are lacking.

Global Case-Fatality Rates in Pediatric Severe Sepsis and Septic Shock: A Systematic Review and Meta-analysis

IMPORTANCE

The global patterns and distribution of case-fatality rates (CFRs) in pediatric severe sepsis and septic shock remain poorly described.

OBJECTIVE

We performed a systematic review and meta-analysis of studies of children with severe sepsis and septic shock to elucidate the patterns of CFRs in developing and developed countries over time. We also described factors associated with CFRs.

DATA SOURCES

We searched PubMed, Web of Science, Excerpta Medica database, Cumulative Index of Nursing and Allied Health Literature (CINAHL), and Cochrane Central systematically for randomized clinical trials and prospective observational studies from earliest publication until January 2017, using the keywords "pediatric," "sepsis," "septic shock," and "mortality."

STUDY SELECTION

Studies involving children with severe sepsis and septic shock that reported CFRs were included. Retrospective studies and studies including only neonates were excluded.

DATA EXTRACTION AND SYNTHESIS

We conducted our systematic review and meta-analysis in close accordance to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled case-fatality estimates were obtained using random-effects meta-analysis. The associations of study period, study design, sepsis severity, age, and continents in which studies occurred were assessed with meta-regression.

MAIN OUTCOMES AND MEASURES

Meta-analyses to provide pooled estimates of CFR of pediatric severe sepsis and septic shock over time.

RESULTS

Ninety-four studies that included 7561 patients were included. Pooled CFRs were higher in developing countries (31.7% [95% CI, 27.3%-36.4%]) than in developed countries (19.3% [95% CI, 16.4%-22.7%]; P < .001). Meta-analysis of CFRs also showed significant heterogeneity across studies. Continents that include mainly developing countries reported higher CFRs (adjusted odds ratios: Africa, 7.89 [95% CI, 6.02-10.32]; P < .001; Asia, 3.81 [95% CI, 3.60-4.03]; P < .001; South America, 2.91 [95% CI, 2.71-3.12]; P < .001) than North America. Septic shock was associated with higher CFRs than severe sepsis (adjusted odds ratios, 1.47 [95% CI, 1.41-1.54]). Younger age was also a risk factor (adjusted odds ratio, 0.95 [95% CI, 0.94-0.96] per year of increase in age). Earlier study eras were associated with higher CFRs (adjusted odds ratios for 1991-2000, 1.24 [95% CI, 1.13-1.37]; P < .001) compared with 2011 to 2016. Time-trend analysis showed higher CFRs over time in developing countries than developed countries.

CONCLUSIONS AND RELEVANCE

Despite the declining trend of pediatric severe sepsis and septic shock CFRs, the disparity between developing and developed countries persists. Further characterizations of vulnerable populations and collaborations between developed and developing countries are warranted to reduce the burden of pediatric sepsis globally.

Clinical spectrum and short-term outcome of adult patients with purpura fulminans: a French multicenter retrospective cohort study

PURPOSE

Data on purpura fulminans (PF) in adult patients are scarce and mainly limited to meningococcal infections. Our aim has been to report the clinical features and outcomes of adult patients admitted in the intensive care unit (ICU) for an infectious PF, as well as the predictive factors for limb amputation and mortality.

METHODS

A 17-year national multicenter retrospective cohort study in 55 ICUs in France from 2000 to 2016, including adult patients admitted for an infectious PF defined by a sudden and extensive purpura, together with the need for vasopressor support. Primary outcome variables included hospital mortality and amputation during the follow-up period (time between ICU admission and amputation, death or end of follow-up).

RESULTS

Among the 306 included patients, 126 (41.2%; 95% CI 35.6-46.9) died and 180 (58.8%; 95% CI 53.3-64.3) survived during the follow-up period [13 (3-24) days], including 51/180 patients (28.3%, 95% CI 21.9-35.5) who eventually required limb amputations, with a median number of 3 (1-4) limbs amputated. The two predominantly identified microorganisms were Neisseria meningitidis (63.7%) and Streptococcus pneumoniae (21.9%). By multivariable Cox model, SAPS II [hazard-ratio (HR) = 1.03 (1.02-1.04); p < 0.001], lower leucocytes [HR 0.83 (0.69-0.99); p = 0.034] and platelet counts [HR 0.77 (0.60-0.91); p = 0.007], and arterial blood lactate levels [HR 2.71 (1.68-4.38); p < 0.001] were independently associated with hospital death, while a neck stiffness [HR 0.51 (0.28-0.92); p = 0.026] was a protective factor. Infection with Streptococcus pneumoniae [sub-hazard ratio 1.89 (1.06-3.38); p = 0.032], together with arterial lactate levels and ICU admission temperature, was independently associated with amputation by a competing risks analysis.

CONCLUSION

Purpura fulminans carries a high mortality and morbidity. Pneumococcal PF leads to a higher risk of amputation.

TRIALS REGISTRATION

NCT03216577.

Differences in IgG Fc Glycosylation Are Associated with Outcome of Pediatric Meningococcal Sepsis

Pediatric meningococcal sepsis often results in morbidity and/or death, especially in young children. Our understanding of the reasons why young children are more susceptible to both the meningococcal infection itself and a more fulminant course of the disease is limited. Immunoglobulin G (IgG) is involved in the adaptive immune response against meningococcal infections, and its effector functions are highly influenced by the glycan structure attached to the fragment crystallizable (Fc) region. It was hypothesized that IgG Fc glycosylation might be related to the susceptibility and severity of meningococcal sepsis. Because of this, the differences in IgG Fc glycosylation between 60 pediatric meningococcal sepsis patients admitted to the pediatric intensive care unit and 46 age-matched healthy controls were investigated, employing liquid chromatography with mass spectrometric detection of tryptic IgG glycopeptides. In addition, Fc glycosylation profiles were compared between patients with a severe outcome (death or the need for amputation) and a nonsevere outcome. Meningococcal sepsis patients under the age of 4 years showed lower IgG1 fucosylation and higher IgG1 bisection than age-matched healthy controls. This might be a direct effect of the disease; however, it can also be a reflection of previous immunologic challenges and/or a higher susceptibility of these children to develop meningococcal sepsis. Within the young patient group, levels of IgG1 hybrid-type glycans and IgG2/3 sialylation per galactose were associated with illness severity and severe outcome. Future studies in larger groups should explore whether IgG Fc glycosylation could be a reliable predictor for meningococcal sepsis outcome.

Meningococcal sepsis causes significant mortality and morbidity worldwide, especially in young children. Identification of risk factors for a more fulminant infection would help to decide on appropriate treatment strategies for the individual patients. Immunoglobulin G (IgG) plays an essential role in humoral immune responses and is involved in the adaptive immune response against meningococcal infections. Of great influence on the receptor affinity of IgG is the N-glycan on its fragment crystallizable (Fc) portion. In the present study, we analyzed IgG glycosylation during the fast development of meningococcal sepsis in children, and we were able to identify glycosylation features that are different between meningococcal sepsis patients and healthy controls. These features might be indicative of a higher susceptibility to meningococcal sepsis. In addition, we found glycosylation features in the patients that were associated with illness severity and severe disease outcome, having the potential to serve as a disease outcome predictor.

Neutrophil Extracellular Traps in Children With Meningococcal Sepsis

OBJECTIVES

Children with meningococcal sepsis are highly at risk for fulminant disease, multiple organ failure, and death. Recently, neutrophil extracellular traps levels have been indicated as a marker for severity in different kinds of sepsis. Our aim was to study the role of neutrophil extracellular traposis in meninogococcal sepsis in children.

DESIGN

We measured myeloperoxidase-DNA, a marker for neutrophil extracellular traps, in serum of meningococcal sepsis patients upon admission to PICU, at 24 hours, and at 1 month and studied the association with clinical outcome. Subsequently, we tested whether Neisseria meningitidis, isolated from children with meningococcal sepsis, were able to induce neutrophil extracellular traposis, using confocal microscopy live imaging.

SETTING

We used enzyme-linked immunosorbent assays to measure myeloperoxidase-DNA in patient serum. We also included inflammatory markers that were previously measured in this group.

PATIENTS

We included exclusively children with meningococcal sepsis.

INTERVENTIONS

From each patient, serum was collected for analysis.

MEASUREMENTS AND MAIN RESULTS

Myeloperoxidase-DNA levels at admission (n = 35; median, 0.21 AU/mL; interquartile range, 0.12-0.27) and at 24 hours (n = 39; median, 0.14 AU/mL; interquartile range, 0.09-0.25) were significantly higher than the myeloperoxidase-DNA levels after 1 month (controls: n = 36; median, 0.07 AU/mL; interquartile range, 0.05-0.09; p < 0.001). We did not observe a correlation between myeloperoxidase-DNA levels and mortality, cell-free DNA, or other inflammatory markers. In addition, N. meningitidis are fast and strong inducers of neutrophil extracellular traposis.

CONCLUSIONS

Children admitted to PICU for meningococcal sepsis have higher neutrophil extracellular traps levels at admission and after 24 hours than controls. Neutrophil extracellular traps levels were not associated with outcome, cell-free DNA, or other inflammatory markers. These neutrophil extracellular traps may be induced by N. meningitidis, since these are strong neutrophil extracellular traposis inducers.

Invited review: Neisseria meningitidis lipopolysaccharides in human pathology

Neisseria meningitidis causes meningitis, fulminant septicemia or mild meningococcemia attacking mainly children and young adults. Lipopolysaccharides (LPS) consist of a symmetrical hexa-acyl lipid A and a short oligosaccharide chain and are classified in 11 immunotypes. Lipid A is the primary toxic component of N. meningitidis . LPS levels in plasma and cerebrospinal fluid as determined by Limulus amebocyte lysate (LAL) assay are quantitatively closely associated with inflammatory mediators, clinical symptoms, and outcome. Patients with persistent septic shock, multiple organ failure, and severe coagulopathy reveal extraordinarily high levels of LPS in plasma. The cytokine production is compartmentalized to either the circulation or to the subarachnoid space. Mortality related to shock increases from 0% to > 80% with a 10-fold increase of plasma LPS from 10 to 100 endotoxin units/ml. Hemorrhagic skin lesions and thrombosis are caused by up-regulation of tissue factor which induces coagulation, and by inhibition of fibrinolysis by plasminogen activator inhibitor 1 (PAI-1). Effective antibiotic treatment results in a rapid decline of plasma LPS (half-life 1—3 h) and cytokines, and reduced generation of thrombin, and PAI-1. Early antibiotic treatment is mandatory. Three intervention trials to block lipid A have not significantly reduced the mortality of meningococcal septicemia.

Prognostic markers of meningococcal disease in children: recent advances and future challenges

Meningococcal disease is a life-threatening condition and a major cause of bacterial meningitis and sepsis worldwide. In many fatal cases, meningococcal disease is rapidly progressive and death occurs within hours of the initial symptoms. The early identification of patients at high risk of death would be useful in order to provide aggressive and more personalized clinical management with the proper level of supportive therapy required, contributing to an improvement in the survival rate and reduction in sequelae. The current study aims to review the current published literature about prognostic markers of meningococcal sepsis in children in order to elaborate conclusions and recommendations that could guide clinical practice and further research.

Analgesia-sedation in PICU and neurological outcome: a secondary analysis of long-term neuropsychological follow-up in meningococcal septic shock survivors*

OBJECTIVES

To investigate whether analgesic and sedative drug use during PICU treatment is associated with long-term neurodevelopmental outcome in children who survived meningococcal septic shock.

DESIGN

This study concerned a secondary analysis of data from medical and psychological follow-up of a cross-sectional cohort of all consecutive surviving patients with septic shock and purpura requiring intensive care treatment between 1988 and 2001 at the Erasmus MC-Sophia Children's Hospital. At least 4 years after PICU admission, these children showed impairments on several domains of neuropsychological functioning. In the present study, type, number, and dose of sedatives and analgesics were retrospectively evaluated.

SETTING

Tertiary care university hospital.

PATIENTS

Seventy-seven meningococcal septic shock survivors (median age, 2.1 yr).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Forty-five patients (58%) received one or more analgesic and/or sedative drugs during PICU admission, most commonly benzodiazepines (n = 39; 51%), followed by opioids (n = 23; 30%). In total, 12 different kinds of analgesic or sedative drugs were given. The use and dose of opioids were significantly associated with poor test outcome on full-scale intelligence quotient (p = 0.02; Z = -2.28), verbal intelligence quotient (p = 0.02; Z = -2.32), verbal intelligence quotient subtests (verbal comprehension [p = 0.01; Z = -2.56] and vocabulary [p = 0.01; Z = -2.45]), and visual attention/executive functioning (Trial Making Test part B) (p = 0.03; Z = -2.17). In multivariate analysis adjusting for patient and disease characteristics, the use of opioids remained significant on most neuropsychological tests.

CONCLUSIONS

The use of opioids during PICU admission was significantly associated with long-term adverse neuropsychological outcome independent of severity of illness scores in meningococcal septic shock survivors.

Intravenous immunoglobulin for treating sepsis, severe sepsis and septic shock

BACKGROUND

Mortality from sepsis and septic shock remains high. Results of trials on intravenous immunoglobulins (IVIG) as adjunctive therapy for sepsis have been conflicting. This is an update of a Cochrane review that was originally published in 1999 and updated in 2002 and 2010.

OBJECTIVES

To estimate the effects of IVIG as adjunctive therapy in patients with bacterial sepsis or septic shock on mortality, bacteriological failure rates, and duration of stay in hospital.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 6), MEDLINE (1966 to December 2012), and EMBASE (1988 to December 2012). We contacted investigators in the field for unpublished data. The original search was performed in 1999 and updated in 2002 and 2008.

SELECTION CRITERIA

We included randomized controlled trials comparing IVIG (monoclonal or polyclonal) with placebo or no intervention in patients of any age with bacterial sepsis or septic shock.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the studies for inclusion and undertook methodologic quality assessment and data abstraction. We conducted pre-specified subgroup analyses by type of immunoglobulin preparation.

MAIN RESULTS

We included 43 studies that met our inclusion criteria in this updated review out of 88 potentially eligible studies. The studies included a large polyclonal IVIG trial in neonates that was concluded in 2011 and classified as ongoing in the 2010 version of this review. Pooled analysis of polyclonal and monoclonal IVIG was not done due to clinical heterogeneity. Subgroup analysis of 10 polyclonal IVIG trials (n = 1430) and seven trials on IgM-enriched polyclonal IVIG (n = 528) showed significant reductions in mortality in adults with sepsis compared to placebo or no intervention (relative risk (RR) 0.81; 95% confidence interval (CI) 0.70 to 0.93 and RR 0.66; 95% CI 0.51 to 0.85, respectively). Subgroup analysis of polyclonal IVIG in neonates, which now includes the recently concluded large polyclonal IVIG trial, showed no significant reduction in mortality for standard IVIG (RR 1.00; 95% CI 0.92 to 1.08; five trials, n = 3667) and IgM-enriched polyclonal IVIG (RR 0.57; 95% CI 0.31 to 1.04; three trials, n = 164). Sensitivity analysis of trials with low risk of bias showed no reduction in mortality with polyclonal IVIG in adults (RR 0.97; 95% CI 0.81 to 1.15; five trials, n = 945) and neonates (RR 1.01; 95% CI 0.93 to 1.09; three trials, n = 3561). Mortality was not reduced among patients (eight trials, n = 4671) who received anti-endotoxin antibodies (RR 0.99; 95% CI 0.91 to1.06) while anti-cytokines (nine trials, n = 7893) demonstrated a marginal reduction in mortality (RR 0.92; 95% CI 0.86 to 0.97).

AUTHORS' CONCLUSIONS

Polyclonal IVIG reduced mortality among adults with sepsis but this benefit was not seen in trials with low risk of bias. Among neonates with sepsis, there is sufficient evidence that standard polyclonal IVIG, as adjunctive therapy, does not reduce mortality based on the inclusion of the large polyclonal IVIG trial on neonates. For Ig-M enriched IVIG, the trials on neonates and adults were small and the totality of the evidence is still insufficient to support a robust conclusion of benefit. Adjunctive therapy with monoclonal IVIGs remains experimental.

Association between C-reactive protein levels and outcome in acute lung injury in children

High plasma C-reactive protein (CRP) levels are associated with favorable outcome in adults with acute lung injury (ALI). The association between CRP levels and outcome has not been studied in ALI in children. We performed a historical cohort study in 93 mechanically ventilated children (0-18 years) with ALI. The CRP level within 48 h of disease onset was tested for association with 28-day mortality and ventilator-free days (VFD). Clinical parameters and ventilator settings were evaluated for possible confounding. Fourteen patients died within 28 days. The median (interquartile range) CRP level in nonsurvivors was 126 mg/L (64; 187) compared with 56 mg/L (20; 105) in survivors (p = 0.01). For every 10-mg/L rise in CRP level, the unadjusted odds (95% confidence interval (95% CI)) for mortality increased 8.7% (2.1-15.8%). Cardiovascular organ failure at onset of ALI was the strongest predictor for mortality (odds ratio, 30.5 (6.2-152.5)). After adjustment for cardiovascular organ failure, for every 10-mg/L rise in CRP level, the OR (95% CI) for mortality increased 4.7% (-2.7-12.6%; p = 0.22). Increased CRP levels were associated with a decrease in VFD (ρ = -0.26, p = 0.01).

CONCLUSION

increased plasma CRP levels are not associated with favorable outcome in ALI in children. This is in contrast with findings in adults with ALI.

A new scoring system derived from base excess and platelet count at presentation predicts mortality in paediatric meningococcal sepsis

INTRODUCTION

The aim of this study was to derive a novel prognostic score for mortality in paediatric meningococcal sepsis (MS) based on readily available laboratory markers.

METHODS

A multicentre retrospective cohort study for the consortium set and a single centre retrospective study for replication set. The consortium set were 1,073 children (age 1 week to 17.9 years) referred over a 15-year period (1996 to 2011), who had an admission diagnosis of MS, referred to paediatric intensive care units (PICUs) in six different European centres. The consortium set was split into a development set and validation set to derive the score. The replication set were 134 children with MS (age 2 weeks to 16 years) referred over a 4-year period (2007 to 2011) to PICUs via the Children's Acute Transport Service (CATS), London.

RESULTS

A total of 85/1,073 (7.9%) children in the consortium set died. A total of 16/134 (11.9%) children in the replication set died. Children dying in the consortium set had significantly lower base excess, C-reactive protein (CRP), platelet and white cell count, more deranged coagulation and higher lactate than survivors. Paediatric risk of mortality (PRISM) score, Glasgow meningococcal septicaemia prognosis score (GMSPS) and Rotterdam score were also higher. Using the consortium set, a new scoring system using base excess and platelet count at presentation, termed the BEP score, was mathematically developed and validated. BEP predicted mortality with high sensitivity and specificity scores (area under the curve (AUC) in the validation set=0.86 and in the replication set=0.96). In the validation set, BEP score performance (AUC=0.86, confidence interval (CI): 0.80 to 0.91) was better than GMSPS (AUC=0.77, CI: 0.68, 0.85), similar to Rotterdam (AUC=0.87, CI: 0.81 to 0.93) and not as good as PRISM (AUC=0.93, CI: 0.85 to 0.97).

CONCLUSIONS

The BEP score, relying on only two variables that are quickly and objectively measurable and readily available at presentation, is highly sensitive and specific in predicting death from MS in childhood.

Neisseria meningitidis induces platelet inhibition and increases vascular endothelial permeability via nitric oxide regulated pathways

Despite antibiotic therapy, infections with Neisseria meningitidis still demonstrate a high rate of morbidity and mortality even in developed countries. The fulminant septicaemic course, named Waterhouse-Friderichsen syndrome, with massive haemorrhage into the adrenal glands and widespread petechial bleeding suggest pathophysiological inhibition of platelet function. Our data show that N. meningitidis produces the important physiological platelet inhibitor and cardiovascular signalling molecule nitric oxide (NO), also known as endothelium-derived relaxing factor (EDRF). N. meningitidis -derived NO inhibited ADP-induced platelet aggregation through the activation of soluble guanylyl cyclase (sGC) followed by an increase in platelet cyclic nucleotide levels and subsequent activation of platelet cGMP- and cAMP- dependent protein kinases (PKG and PKA). Furthermore, direct measurement of horseradish peroxidase (HRP) passage through a vascular endothelial cell monolayer revealed that N. meningitidis significantly increased endothelial monolayer permeability. Immunfluorescence analysis demonstrated NO dependent disturbances in the structure of endothelial adherens junctions after co-incubation with N. meningitidis . In contrast to platelet inhibition, the NO effects on HBMEC were not mediated by cyclic nucleotides. Our study provides evidence that NO plays an essential role in the pathophysiology of septicaemic meningococcal infection.

Review of meningococcal infection in children at a United Kingdom hospital

Sixty-nine children were identified and evaluable. Forty-one (60%) presented with hypotension and/or abnormal neurological signs. In 34 (49%) a petechial rash was present on admission. Of note, 13 (19%) had a non-petechial rash, and rash was absent in 19 (28%). Twenty-one (30%) presented with meningism or meningitis. In one child the illness was so mild that the child was discharged prior to making a diagnosis. Five children died (7%). Sixty-three cases (91%) were diagnosed by blood or cerebrospinal fluid culture; these investigations remain the mainstay of diagnosis.

Two centuries of meningococcal infection: from Vieusseux to the cellular and molecular basis of disease

Scientific knowledge of meningococcal infection has increased greatly since the epidemic nature of the illness was first described by Vieusseux at the dawn of the nineteenth century. In fact, revolutionary advances have been made in public-health measures, antimicrobial therapy, diagnostic procedures, anti-inflammatory drugs and supportive care facilities. Based on the knowledge accumulated to date, it is generally accepted that the pathogenesis of meningococcal infection involves multiple links that interconnect in a complex web of phenomena from Neisseria meningitidis attachment to meningococcal sepsis or meningitis. In fact, a myriad of strongly interacting inflammatory molecules and cells have been implicated in neisserial infection, illustrating the complexity of meningococcal pathogenesis. In addition, many of these signallers are critically involved in outcomes in the human host. Deciphering the pathogenesis of meningococcal infection could expand our knowledge and provide important clues to the host-pathogen interaction, as well as leading to the development of new therapeutic tools. Herein, we review the history of the discovery and characterization of meningococcal disease, epidemiological features of the disease with an emphasis on recent developments in Brazil, the cellular and molecular basis of disease, and discuss diagnosis and therapy.

Improved survival of children with sepsis and purpura: effects of age, gender, and era

Background

To gain insight into factors that might affect results of future case-control studies, we performed an analysis of children with sepsis and purpura admitted to the paediatric intensive care unit (PICU) of Erasmus MC-Sophia Children's Hospital (Rotterdam, The Netherlands).

Methods

Between 1988 and 2006, all 287 children consecutively admitted with sepsis and purpura were included in various sepsis studies. Data regarding age, gender, ethnicity, serogroup of Neisseria meningitidis, severity, therapy, and survival were collected prospectively. These data were pooled into one database and analyzed retrospectively.

Results

The case fatality rate (CFR) from sepsis and purpura was 15.7%. During the study period, survival improved significantly. Younger age was significantly associated with more severe disease and a higher CFR. Children under the median age of 3.0 years had an increased risk of case fatality (odds ratio 4.3, 95% confidence interval 2.1 to 9.2; p < 0.001). Gender was not associated with CFR. However, males did have higher Paediatric Risk of Mortality scores, fewer PICU-free days, and more presence of shock. The course of sepsis and purpura was not related to ethnic origin. A causative organism was isolated in 84.3% of cases. N. meningitidis was the major organism (97.5%). Although N. meningitidis serogroup B was observed more often in younger children, serogroups were not associated with severity or survival. During the study period, the use of inotropic agents and corticosteroids changed substantially (less dopamine and more dobutamine, norepinephrine, and corticosteroids).

Conclusion

Age and gender are determinants of severity of paediatric sepsis and purpura. Survival rates have improved during the last two decades.

Thrombin-activatable fibrinolysis inhibitor is associated with severity and outcome of severe meningococcal infection in children

BACKGROUND AND OBJECTIVES

In pediatric meningococcal sepsis, an imbalance between coagulation and fibrinolysis and proinflammatory action play major roles. We hypothesized that thrombin activatable fibrinolysis inhibitor (TAFI) and/or TAFI activation markers are involved in the pathogenesis of meningococcal sepsis.

PATIENTS AND METHODS

Children with severe meningococcal sepsis (n = 112) previously included in Rotterdam-based trials participated in this study. Clinical and laboratory parameters and severity scores were assessed. TAFI and TAFI activation markers were determined: TAFI activation peptide (TAFI-AP) and (in)activated TAFI [TAFIa(i)]. The -438G/A, Ala147Thr, and Thr325Ile polymorphisms were genotyped.

RESULTS

TAFI levels were significantly decreased in patients with meningococcal disease at admission compared to the convalescence state. TAFI was decreased in patients with septic shock vs. those with no shock. TAFI-AP levels were increased in patients with disseminated intravascular coagulation (DIC) vs. patients without DIC. TAFI-AP and TAFIa(i) were significantly increased in non-survivors vs. survivors. TAFI-AP levels and the TAFI-AP/TAFI ratio were also strongly correlated to severity scores and laboratory parameters. The TAFI 325Ile/Ile genotype was overrepresented in patients with DIC.

CONCLUSIONS

Activation markers of TAFI were associated with the occurrence of DIC and mortality in meningococcal sepsis patients. A determination of TAFI, TAFI-AP, and TAFIa(i) is required to enable coherent interpretation of the role of TAFI in disease.

Association between high levels of blood macrophage migration inhibitory factor, inappropriate adrenal response, and early death in patients with severe sepsis

BACKGROUND

Identification of new therapeutic targets remains an imperative goal to improve the morbidity and mortality associated with severe sepsis and septic shock. Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine and counterregulator of glucocorticoids, has recently emerged as a critical mediator of innate immunity and experimental sepsis, and it is an attractive new target for the treatment of sepsis.

METHODS

Circulating concentrations of MIF were measured in 2 clinical trial cohorts of 145 pediatric and adult patients who had severe sepsis or septic shock caused predominantly by infection with Neisseria meningitidis or other gram-negative bacteria, to study the kinetics of MIF during sepsis, to analyze the interplay between MIF and other mediators of sepsis or stress hormones (adrenocorticotropic hormone and cortisol), and to determine whether MIF is associated with patient outcome.

RESULTS

Circulating concentrations of MIF were markedly elevated in 96% of children and adults who had severe sepsis or septic shock, and they remained elevated for several days. MIF levels were correlated with sepsis severity scores, presence of shock, disseminated intravascular coagulation, urine output, blood pH, and lactate and cytokine levels. High levels of MIF were associated with a rapidly fatal outcome. Moreover, in meningococcal sepsis, concentrations of MIF were positively correlated with adrenocorticotropic hormone levels and negatively correlated with cortisol levels and the cortisol:adrenocorticotropic hormone ratio, suggesting an inappropriate adrenal response to sepsis.

CONCLUSIONS

MIF is markedly and persistently up-regulated in children and adults with gram-negative sepsis and is associated with parameters of disease severity, with dysregulated pituitary-adrenal function in meningococcal sepsis, and with early death.

Elevated procalcitonin as a diagnostic marker in meningococcal disease

Patients with meningococcal disease who seek medical attention can create a diagnostic dilemma for clinicians due to the nonspecific nature of the disease's presentation. This study assesses the diagnostic accuracy of procalcitonin levels in the setting of meningococcal disease. Two emergency department cohorts (A and B) were studied between 2002 and 2005, during the current epidemic of serogroup B meningococcal disease in New Zealand. Cohort A consisted of 171 patients, all with confirmed meningococcal disease (84 children, 87 adults). Cohort B consisted of a large (n=1,524) consecutively recruited population of febrile patients who presented to the emergency department, 28 of whom had confirmed meningococcal disease. Within the meningococcal disease cohort (cohort A), the geometric mean procalcitonin level was 9.9 ng/ml, with levels being higher in children than in adults (21.6 vs. 4.6 ng/ml, p=0.01). The overall sensitivity of elevated procalcitonin, using a cutoff of 2.0 ng/ml in children and 0.5 ng/ml in adults, was 0.93 (95%CI: 0.88-0.96). Despite the higher cutoff level for paediatric patients, a trend towards greater sensitivity existed in children (0.96 vs. 0.90; p=0.08). Elevated procalcitonin was correlated with whole blood meningococcal load (r=0.50) and Glasgow Meningococcal Sepsis Prognostic Score (r=0.40). Within the cohort of patients who were febrile on presentation (cohort B), the specificity of elevated procalcitonin in meningococcal disease was 0.85 (95% CI: 0.83-0.87), the positive and negative likelihood ratios were 6.1 and 0.08, respectively, and the sensitivity of elevated procalcitonin (0.93; 95% CI: 0.76-0.99) was corroborated. Measurement of procalcitonin is a useful tool in patients with nonspecific febrile illnesses when the possibility of meningococcal disease is present. The diagnostic accuracy surpasses that of current early laboratory markers, allowing results to be used to guide decisions about patient management.

Disseminated intravascular coagulation in pediatric patients: clinical and laboratory features and prognostic factors influencing the survival

Although disseminated intravascular coagulation (DIC) has been a well-known disorder for many years, there is lack of sufficient number of clinical trials about incidence, frequency of underlying disorders, and prognosis of DIC in children. The aim of this study was to evaluate the frequency, etiologic factors, and clinical and laboratory findings of DIC and to determine the prognostic factors influencing the mortality in hospitalized pediatric patients. Medical records of 5535 children who were hospitalized were investigated. Sixty-two patients who were diagnosed as acute DIC were enrolled. The frequency of DIC was 1.12%. The underlying etiologic factors were infection in 59 patients (95.2%) and major trauma in 3 patients (4.8%). The frequency of bleeding and thrombosis was 48.8 and 4.8%. Respiratory, cardiovascular, hepatic, renal, neurologic, and gastrointestinal dysfunction was present in 71, 67.7, 35.5, 16.1, 16.1 and 11.3% of patients, respectively. Respiratory and cardiovascular dysfunctions were significantly associated with mortality. Multiorgan dysfunction syndrome (MODS) was present in 85.5% of the patients, and 54.8% of the patients had developed acute respiratory distress syndrome (ARDS). Mortality rate was significantly high in patients with MODS and ARDS. In multivariete logistic regression analysis, only ARDS and cardiovascular dysfunction had predictive and prognostic value on mortality. None of the diagnostic laboratory tests had predictive or prognostic value and the degree of abnormality of these tests did not show any correlation with mortality. In conclusion, DIC is not a rare disorder in hospitalized children, especially in patients with sepsis, and MODS, ARDS, and respiratory and cardiovascular system dysfunctions are poor prognostic factors.

Randomized Trial of Volume Expansion with Albumin or Saline in Children with Severe Malaria: Preliminary Evidence of Albumin Benefit

BACKGROUND

Metabolic acidosis is the best predictor of death in children with severe falciparum malaria; however, its treatment presents a therapeutic dilemma, because acidosis and hypovolemia may coexist with coma, which can be associated with elevated intracranial pressure. We postulated that volume resuscitation with albumin might correct acidosis and hypovolemia with a lower risk of precipitating cerebral edema than crystalloid. In an open-label, randomized, controlled trial, we compared the safety of resuscitation with albumin to saline in Kenyan children with severe malaria.

METHODS

We randomly assigned children with severe malaria and metabolic acidosis (base deficit, >8 mmol/L) to receive fluid resuscitation with either 4.5% albumin or normal saline. A control (maintenance only) group was only included for patients with a base deficit of <15 mmol/L. The primary outcome measure was the percentage reduction in base deficit at 8 h. Secondary end points included death, the requirement for rescue therapies, and neurological sequelae in survivors.

RESULTS

Of 150 children recruited for the trial, 61 received saline, 56 received albumin, and 33 served as control subjects. There was no significant difference in the resolution of acidosis between the groups; however, the mortality rate was significantly lower among patients who received albumin (3.6% [2 of 56 patients]) than among those who received saline (18% [11 of 61]; relative risk, 5.5; 95% confidence interval, 1.2-24.8; P=.013).

CONCLUSIONS

In high-risk children with severe malaria and acidosis, fluid resuscitation with albumin may reduce mortality. Our study design did not enable us to determine whether saline administration is preferable to fluid restriction or whether saline administration is actually hazardous. Further studies are needed to confirm our findings before definitive treatment recommendations can be made.

Genomic polymorphic profiles in an Irish population with meningococcaemia: is it possible to predict severity and outcome of disease?

Patients with meningococcal disease have increased plasma levels of proinflammatory cytokines IL-6, IL-1beta, and TNF-alpha, with higher levels associated with fatal outcome. This study investigated whether polymorphisms in genes encoding these cytokines, and in those encoding anti-inflammatory IL-10 and IL-1Ra, are associated with the outcome in patients with meningococcal disease. Seven polymorphisms were genotyped in 183 meningococcal disease patients and 389 controls. The IL-6 -174 G/G and IL-10 -1082 A/A genotypes were more frequent in nonsurvivors compared with survivors (P=0.023 IL-6, 0.25 IL-10), and in patients with severe disease compared to those with mild disease (P=0.037 IL-6, 0.0078 IL-10). An association was also found between meningococcal disease and the IL-1RN VNTR polymorphism, but no association was observed with the LTA +252, TNF -308, IL-10 -592, or IL-1B +3953 polymorphisms. We conclude that genetic variability in the IL-6, IL-10, and IL-1RN genes is associated with a poor outcome in meningococcal disease.

The potential role of procalcitonin in the emergency department management of febrile young adults during a sustained meningococcal epidemic

OBJECTIVE

To prospectively investigate the diagnostic characteristics of procalcitonin as an aid in the diagnosis of meningococcal disease in febrile young adults presenting to the Waikato Hospital emergency department during a sustained meningococcal epidemic.

METHODS

The study population were emergency department patients aged 14-40 years presenting with either a temperature > or = 38.0 degrees C without an obvious focus of infection, or symptoms consistent with meningococcal disease. All had procalcitonin levels, N. meningitidis PCR, blood +/- CSF cultures.

RESULTS

One hundred and eighty-three patients presented with undifferentiated febrile illness over a 9 month study period. Nine were subsequently shown to have meningococcal disease. A positive procalcitonin (> or = 0.5 ng/mL) had a sensitivity of 100% (CI 66.4-100), specificity 89% (CI 83.1-93.1), negative predictive value 100% (CI 97.6-100) and positive predictive value 32% (CI 15.9-52.4) for meningococcal disease.

CONCLUSIONS

The finding of a procalcitonin level > or = 0.5 ng/mL in young adults with undifferentiated fever indicates an increased chance that the presenting illness may be meningococcal disease. In New Zealand's continuing meningococcal epidemic empirical antibiotics should be strongly considered in those with elevated procalcitonin levels in the hope of reducing meningococcal disease deaths due to delays in antibiotic administration.

Host genetic determinants of Neisseria meningitidis infections

The clinical presentation of infections caused by Neisseria meningitidis is highly diverse. Some patients develop meningitis, and others present with sepsis or even septic shock. After invasion of the bloodstream by the bacteria, three main cascade pathways are activated. These are the complement system, the inflammatory response, and the coagulation and fibrinolysis pathway. These pathways do not act independently but are able to interact with each other. Genetic polymorphisms among components of these pathways have been shown to be involved in the susceptibility, severity, and outcome of meningococcal disease. We review knowledge of genetic variations associated with susceptibility to and severity of meningococcal infection. Complement deficiencies and defects in sensing or opsonophagocytic pathways, such as the rare Toll-like receptor 4 single nucleotide polymorphisms (SNPs) and combinations of inefficient variants of Fcgamma-receptors, seem to have the most important role in genetically established susceptibility. Effect on severity has repeatedly been reported for FcgammaRIIa and plasminogen activator inhibitor type 1 (PAI1) polymorphisms. Outcome effects have been confirmed for SNPs in properdin deficiencies, PAI1 and combination of the -511C/T SNP in interleukin 1beta, and the +2018C/T SNP in interleukin RN. Conflicting results are reported for the effect of the -308G/A promoter polymorphism in tumour necrosis factor (TNF) alpha. These differences may reflect discrepancies in group definitions between studies or the influence of additional SNPs in the TNFalpha promoter, which can form haplotypes representing different cytokine production capacity. For several SNPs, the potential effect on susceptibility, severity, or outcome has not yet been confirmed in an independent study.

Activation of protein C following infusion of protein C concentrate in children with severe meningococcal sepsis and purpura fulminans: a randomized, double-blinded, placebo-controlled, dose-finding study

BACKGROUND

Meningococcal septic shock in children results in high mortality and morbidity, and decreased protein C levels in these patients are associated with a poor outcome. We carried out a randomized, double-blinded, placebo-controlled study by supplying protein C concentrate. This phase 2 study was designed to assess the activation process of protein C and to study the dosing regimen of protein C concentrate in children with purpura fulminans and meningococcal septic shock in the perspective of a possible phase 3 trial.

METHODS

Forty children were randomized to receive placebo or protein C concentrate (200 IU/kg, 400 IU/kg, or 600 IU/kg), for a maximum of 7 days. Clinical and laboratory data, including plasma levels of protein C and activated protein C (APC), were collected at various time points. All patients received standard therapy for septic shock, including antibiotics, inotropic/vasoactive drugs, and blood products.

RESULTS

Increased APC levels relative to baseline were observed for the 27 of 28 patients treated with protein C concentrate, and the areas under the curve of protein C and APC were correlated with the dosage of protein C concentrate administered. Activation of coagulation, as evidenced by d-dimer levels, as well as the ratio of thrombin vs. APC normalized significantly faster with increasing dosages of protein C concentrate. No adverse reactions related to protein C concentrate were observed. Nine of the 40 (23%) patients died, and five survivors required amputations, with no differences in these rates among the randomized groups. Baseline APC levels were positively correlated with sequential organ failure assessment and pediatric risk of mortality scores and with d-dimers, tumor necrosis factor-alpha, interleukin-1, interleukin-6, interleukin-8, plasminogen activator inhibitor-1, TAT complexes, and PAP complexes.

CONCLUSIONS

Treatment with protein C concentrate is safe in children with purpura fulminans and meningococcal septic shock and leads to dose-related increases of plasma APC and resolution of coagulation imbalances.

Comparison of prediction models for adverse outcome in pediatric meningococcal disease using artificial neural network and logistic regression analyses

The objective of this study was to compare artificial neural network (ANN) and multivariable logistic regression analyses for prediction modeling of adverse outcome in pediatric meningococcal disease. We analyzed a previously constructed database of children younger than 20 years of age with meningococcal disease at four pediatric referral hospitals from 1985-1996. Patients were randomly divided into derivation and validation datasets. Adverse outcome was defined as death or limb amputation. ANN and multivariable logistic regression models were developed using the derivation set, and were tested on the validation set. Eight variables associated with adverse outcome in previous studies of meningococcal disease were considered in both the ANN and logistic regression analyses. Accuracies of these models were then compared. There were 381 patients with meningococcal disease in the database, of whom 50 had adverse outcomes. When applied to the validation data set, the sensitivities for both the ANN and logistic regressions models were 75% and the specificities were both 91%. There were no significant differences in any of the performance parameters between the two models. ANN analysis is an effective tool for developing prediction models for adverse outcome of meningococcal disease in children, and has similar accuracy as logistic regression modeling. With larger, more complete databases, and with advanced ANN algorithms, this technology may become increasingly useful for real-time prediction of patient outcome.

Influence of serogroup on the presentation, course, and outcome of invasive meningococcal disease in children in the Republic of Ireland, 1995-2000

To test the hypothesis that the infecting meningococcal serogroup modulates the presentation, course, and outcome of invasive meningococcal disease (IMD), we performed a retrospective review of cases of IMD in 407 children from 2 tertiary referral centers and 2 regional centers in Ireland. Patients infected with serogroup C meningococci (n=104) were older than those infected with serogroup B (n=303; median, 2.5 vs. 1.5 years; P=.04); all other demographic and clinical parameters were similar for the 2 groups. Among serogroup B patients, mortality was 3.6% and morbidity was 10%; for serogroup C patients, mortality was 4.8% and morbidity was 12.5% (P=.81 and P=.76, respectively). Serogroup C-associated sequelae more often were multiple (P=.003). Despite the introduction of serogroup C conjugate vaccine into the routine immunization schedule of some countries, ongoing morbidity from IMD is anticipated, because group B disease was very similar to group C disease in this pediatric population.

Intravenous immunoglobulin for treating sepsis and septic shock

BACKGROUND

Death from severe sepsis and septic shock is common, and researchers have explored whether antibodies to the endotoxins in some bacteria reduces mortality.

OBJECTIVES

To estimate the effects of intravenous immunoglobulin (IVIG) in patients with bacterial sepsis or septic shock on mortality, bacteriological failure rates, and duration of stay in hospital.

SEARCH STRATEGY

We searched the Cochrane Infectious Diseases Group specialized register up to November 2001; the Cochrane Controlled Trials Register, The Cochrane Library issue 4, 2001; MEDLINE 1966 to November 2001; and EMBASE 1988 to September 2001. We contacted investigators active in the field for unpublished data.

SELECTION CRITERIA

Randomised trials comparing intravenous immunoglobulin (monoclonal or polyclonal) with placebo or no intervention, in patients with bacterial sepsis or septic shock.

DATA COLLECTION AND ANALYSIS

Inclusion criteria, trial quality assessment, and data abstraction were done in duplicate. We conducted pre-specified subgroup analyses by type of immunoglobulin preparation.

MAIN RESULTS

Twenty-seven out of 55 studies met our inclusion criteria. Pooled analysis of all types of IVIG preparations revealed a significant trend toward reduction of mortality (n= 8,856; RR=0.91; 95%CI 0.86-0.96). Overall mortality was reduced in patients who received polyclonal IVIG (n=492; RR=0.64; 95% CI 0.51 to 0.80). For the two high-quality trials on polyclonal IVIG, the RR for overall mortality was 0.30, but the confidence interval was wide (95% CI 0.09 to 0.99, n=91). Mortality was not reduced among patients who received monoclonal antibodies such as anti-endotoxins (n=2,826 in 5 good-quality studies; RR=0.97; 95% CI 0.88 to 1.07) or anti-cytokines (n=4,318; RR=0.93; 95% CI 0.86 to 1.01). A few studies measured secondary outcomes (deaths from sepsis or length of hospitalisation) but no differences in the intervention and control groups were identified except among those who received polyclonal IVIG, where sepsis-related mortality was significantly reduced (n=161; RR=0.35; 95% CI 0.18 to 0.69).

REVIEWER'S CONCLUSIONS

Polyclonal IVIG significantly reduced mortality and and is a promising adjuvant in the treatment of sepsis and septic shock. However, all the trials were small and the totality of the evidence is insufficient to support a robust conclusion of benefit. Adjunctive therapy with monoclonal IVIGs remains experimental.

Epidemiology and prognostic factors in meningococcal disease in a small island population: Malta 1994-1998

STUDY OBJECTIVE

To review the epidemiology of meningococcal disease in Malta over the period 1994-1998, and to identify factors at presentation and in the management of meningococcal disease which may influence mortality.

DESIGN

All admissions with meningococcal disease to a national hospital in a population-based study over the period 1994-1998 were studied retrospectively.

MAIN RESULTS

Fifty-six cases were diagnosed over 1994-1998, the incidence rising from 0.8/100,000 to 7.2/100,000 total population (p < 0.0001). The median time interval from arrival at hospital to administration of parenteral antibiotic decreased over the 5-year period from 4.4 to 1.2 hours (p = 0.025), with no significant change in the case-fatality rate. There was no association between the time interval from arrival at hospital to parenteral antibiotic administration, and mortality. The following features at presentation were associated with increased mortality: older age (p = 0.03), meningococcaemia compared with meningitis (p = 0.05), shock (p < 0.0001), disseminated intravascular coagulation (p = 0.0001), a normal/low white blood cell count (p = 0.0003), a low platelet count (p = 0.0001) and a high serum creatinine (p = 0.003).

CONCLUSIONS

The upsurge of cases in the population was accompanied by a decrease in intervention time in the general hospital, probably due to increased awareness of the disease. This study did not show a positive relationship between early in-hospital administration of antibiotics and improved survival, probably because antibiotics were given earlier to those with fulminant disease and, with therefore, an inherently worse outcome. Stratification of cases by severity on admission is recommended in future studies.

Coagulation in severe sepsis: a central role for thrombomodulin and activated protein C

OBJECTIVES

To review the mechanisms that cause coagulation abnormalities in sepsis, focusing on the interaction between the vascular endothelium and the circulating coagulation factors, particularly the role of the protein C pathway and thrombomodulin.

DATA SOURCES/STUDY SELECTION

Published research abstracts and review articles on the experimental and clinical investigation of the pathophysiology of disseminated intravascular coagulation in sepsis.

DATA EXTRACTION AND SYNTHESIS

The data provide increasing evidence that the coagulopathy seen in sepsis is a result of a complex imbalance of pro- and anticoagulant pathways. Whereas previous research has largely studied events in the plasma, it is now apparent that reactions on cell surfaces such as the vascular endothelium are important in the control of the regulatory pathways.

CONCLUSIONS

The plasma components of the protein C pathway are down-regulated in sepsis. Decreased thrombomodulin expression may cause defective function of the endothelial component of this pathway in septic patients. Treatments must be designed to overcome any functional defect.

Can generic scores (Pediatric Risk of Mortality and Pediatric Index of Mortality) replace specific scores in predicting the outcome of presumed meningococcal septic shock in children?

OBJECTIVE

To compare, in children with septic shock and purpura, the accuracy in predicting death of two specific scores (the MenOPP bedside clinical [MOC] score of Gedde Dahl and the score of Groupe Francophone de Réanimation Pédiatrique [GFRP]), the C-reactive protein (CRP) level, and the two pediatric generic scores (the Pediatric Risk of Mortality [PRISM] and Pediatric Index of Mortality [PIM] scores).

DESIGN

Prospective, population-based study with analysis of previous comparative studies.

SETTING

A 14-bed pediatric intensive care unit in a university hospital.

PATIENTS

All children admitted consecutively to the pediatric intensive care unit with septic shock and purpura (n = 58, with 16 deaths [27.6%]) from January 1993 to May 2000.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The MOC and GFRP scores and the CRP level were prospectively determined at admission. The PRISM score was prospectively calculated within 24 hrs of admission or at the time of death, and the PIM score was calculated retrospectively between 1993 and 1997 and then prospectively from admission data. The nonparametric estimate of the area under the receiver operating characteristic curves (AUC) was calculated from the raw data using the Wilcoxon-Mann-Whitney two-sample statistic, and the standard error of the AUCs was calculated with DeLong's method. All the scores had an AUC >0.80, the PRISM probability of death having the best one (0.96 +/- 0.02). The PRISM value, which is easier to calculate, had an AUC of 0.95 +/- 0.02. The PRISM score performed significantly better than the PIM score (AUC, 0.83 +/- 0.06; p <.01) and the CRP level (AUC, 0.80 +/- 0.06; p <.01); however, there was no significant difference between the MOC (AUC, 0.91 +/- 0.04) and GFRP scores (AUC, 0.87 +/- 0.05). Analyzing literature and calculating AUCs from original data of previous studies, we observed that the superiority of the PRISM score had never been demonstrated in meningococcal diseases.

CONCLUSIONS

The PRISM score performed better than the PIM score, and was not surpassed by specific scores. Thus, we propose its use for outcome prediction in children with septic shock and purpura. However, if the PRISM score is to be used as inclusion criterion for clinical trials, it should be evaluated within a few hours after admission.

Management of sepsis and septic shock in infants and children

Sepsis and septic shock constitute an important cause of morbidity and mortality in critically ill children. Thus, the systemic response to infection and its management remains a major challenge in clinical medicine. Apart from antibiotic administration, the majority of available therapies are limited to supportive strategies, although considerable efforts are being undertaken to devise innovative approaches that modulate host inflammatory responses. In suspected sepsis, 2 or 3 days' empiric antibiotic therapy should begin immediately after cultures have been obtained without awaiting results. Antibiotics should be re-evaluated when the results of the cultures and susceptibility tests are available. The initial antibiotic (combination) is determined by the likely causative agent, susceptibility patterns within a specific institution, CNS penetration, toxicity, and the patient's hepatic and renal function. The likely offending micro-organism in turn depends primarily on the patient's age, coexistence of any premorbid condition leading to impaired immune response, and the presenting signs and symptoms. Close attention to cardiovascular, respiratory, fluid and electrolyte, haematological, renal and metabolic/nutritional support is essential to optimise outcome. Fluid resuscitation is of utmost importance to overcome hypovolaemia on the basis of a diffuse capillary leak. Monitoring and normalisation of the heart rate is essential. In case of nonresponse to fluid resuscitation, inotropic and vasoactive agents are commonly used to increase cardiac output, maintain adequate blood pressure and enhance oxygen delivery to the tissue. Because respiratory distress syndrome is seen in about 40% of critically ill children with septic shock, increased inspired oxygen is essential. To provide optimal relief from respiratory muscle fatigue and facilitate the provision of positive airway pressure, early intubation and mechanical ventilation should be considered. Renal support is essential to avoid prolonged renal shutdown in hypoperfusion states. Haematological support comprises replacement therapy of clotting factors to overcome disseminated intravascular coagulation. Metabolic support may include glucose support, extraction of ammonia from the body and recognition of liver dysfunction. Nutritional support may modify the inflammatory host response, and early enteral feeding can improve outcome in critical illness. To date, glucocorticoid and non-glucocorticoid anti-inflammatory agents have not shown significant benefit in septic patients.

Early filtration and mortality in meningococcal septic shock?

Following the introduction of a policy of early therapeutic filtration for presumed meningococcal septicaemic shock, the overall mortality has decreased.

[Fatality rate in the epidemiology of meningococcal disease: study in the region of Campinas, SP, Brazil, 1993 to 1998]

OBJECTIVE

To analyze the trends of the meningococcal disease cumulative incidence and case-fatality rate in the region of Campinas, Brazil, an area that encircles five cities and 1.2 million inhabitants, from 1993 to 1998.

METHODS

A longitudinal retrospective study of all case records (375) obtained from the regional epidemiological surveillance system was carried out. A logistic regression analysis allowed identifying the risk factors related to fatal outcomes of meningococcal disease.

RESULTS

The highest fatality rates (23.8%) were seen in the period of 1996 and 1997, coinciding with the incidence peaks of serogroup B Neisseria and a high percentage of septicemia cases. Also at the same period there was registered a poor etiological investigation of the cases. A seasonal pattern and the predomination of strains B:4:P1.15 and C:2b:P1.3 were observed. In the logistic regression analysis, the risk factors related to fatality were: septicemia with or without meningitis (adjusted odds ratio [OR(aj)] = 13.88 and 95% confidence interval [CI] = 4.68 - 42.13); age over 30 years (OR(aj) = 6.42; CI = 2.32 - 17.80); age under 1 year (OR(aj) = 2.95; CI = 1.55 - 5.63); and serogroup B (OR(aj) = 2.33; CI = 1.14 - 4.79).

CONCLUSIONS

Septicemia, age and serogroup were predictive variables related to a fatal outcome. In 1996 and 1997, case-fatality rates were high, indicating the need to further assessment of the quality of the services delivered and their readiness to take preventive action. The lack of etiological identification in many cases precluded more accurate inferences about the epidemiological behavior of Neisseria meningitidis in the region.

Risk factors predicting complications in blood culture-proven typhoid fever in adults

To create a prognostic model for complications of blood culture-proven typhoid fever in adults (> or = 15 y old), a retrospective cohort was assembled though review of the medical records of the hospitalized patients treated for typhoid fever over a 3-y period ending January 1995. Of the 59 patients included, 21 (35.6%) developed various complications of typhoid fever. No patient included died. Four baseline variables (abdominal pain, systolic blood pressure < 100 mmHg, hypoalbuminaemia < 32 g/l and laboratory evidence of disseminated intravascular coagulation) were independently associated with complications and were used to create a prognostic model. The prediction accuracy of the model was determined using the concordance index (c-index). The results (c-index, 0.915 [95%, CI, 89.0-93.0]) showed that the model predicted complications significantly better than chance. The model stratified patients into 3 prognostic stages: low risk for complications (0%; stage I), intermediate risk (42.9%; stage II) and high risk (92.3%; stage III) (p = 0.001). If validated in other settings, it will help clinicians in predicting complications in patients with blood culture-proven typhoid fever on admission.

Protein C substitution in sepsis-associated purpura fulminans

OBJECTIVE

To assess the effect of protein C (PC) substitution on imminent peripheral necroses and overall outcome in patients with sepsis-associated purpura fulminans.

DESIGN

Case series.

SETTING

Intensive care units of two university hospitals.

PATIENTS

A total of 12 patients with purpura fulminans, disseminated intravascular coagulation and imminent peripheral necroses in association with sepsis caused by Neisseria meningitidis (n = 5), Streptococcus pneumoniae (n = 2), Capnocytophaga canimorsus (n = 2), and Staphylococcus aureus (n = 1). In two patients, no pathogens were identified.

INTERVENTIONS

Intravenous administration of PC concentrate (100 IU/kg every 6 hrs). In addition, antithrombin III substitution, antimicrobial therapy, hemodynamic support, and mechanical ventilation in all patients and hemodiafiltration in 10 patients.

MAIN RESULTS

After the onset of PC, progressive peripheral ischemia was reversed irrespective of the etiology of infection. Laboratory variables reflecting disseminated intravascular coagulation improved rapidly, although the recovery of the platelet count was retarded in the patients who subsequently died. No drug-related adverse events were noted. Amputations were necessary in two patients, and necrotic tips of fingers and toes were macerated in a third. The hospital mortality was 42%. Of the five lethal cases, two were caused by S. pneumoniae, one by N. meningitidis, one by C. canimorsus, and one by an unknown pathogen.

CONCLUSIONS

This article provides encouraging results on the use of PC substitution in meningococcal purpura and presents new data on the administration of this drug to patients with septic purpura caused by other bacterial species. By clinical judgment, PC limited the extent of tissue necrosis. The small number of patients does not allow for any conclusions on the potential effect of PC on mortality. A controlled and randomized study with a larger number of patients is needed before any recommendations can be given on the use of PC in sepsis-related purpura fulminans and shock.

Disseminated intravascular coagulation and purpura fulminans secondary to infection

Infection is one of the commonest causes of disseminated intravascular coagulation (DIC). DIC is a complex disorder that results from an imbalance of the pro- and anticoagulant regulatory pathways. This chapter will explain the cellular and molecular basis of the disorder and consider the rationale behind current and experimental treatment strategies.

Update on meningococcal disease with emphasis on pathogenesis and clinical management

The only natural reservoir of Neisseria meningitidis is the human nasopharyngeal mucosa. Depending on age, climate, country, socioeconomic status, and other factors, approximately 10% of the human population harbors meningococci in the nose. However, invasive disease is relatively rare, as it occurs only when the following conditions are fulfilled: (i) contact with a virulent strain, (ii) colonization by that strain, (iii) penetration of the bacterium through the mucosa, and (iv) survival and eventually outgrowth of the meningococcus in the bloodstream. When the meningococcus has reached the bloodstream and specific antibodies are absent, as is the case for young children or after introduction of a new strain in a population, the ultimate outgrowth depends on the efficacy of the innate immune response. Massive outgrowth leads within 12 h to fulminant meningococcal sepsis (FMS), characterized by high intravascular concentrations of endotoxin that set free high concentrations of proinflammatory mediators. These mediators belonging to the complement system, the contact system, the fibrinolytic system, and the cytokine system induce shock and diffuse intravascular coagulation. FMS can be fatal within 24 h, often before signs of meningitis have developed. In spite of the increasing possibilities for treatment in intensive care units, the mortality rate of FMS is still 30%. When the outgrowth of meningococci in the bloodstream is impeded, seeding of bacteria in the subarachnoidal compartment may lead to overt meningitis within 24 to 36 h. With appropriate antibiotics and good clinical surveillance, the mortality rate of this form of invasive disease is 1 to 2%. The overall mortality rate of meningococcal disease can only be reduced when patients without meningitis, i.e., those who may develop FMS, are recognized early. This means that the fundamental nature of the disease as a meningococcus septicemia deserves more attention.

Update on meningococcal disease with emphasis on pathogenesis and clinical management

The only natural reservoir of Neisseria meningitidis is the human nasopharyngeal mucosa. Depending on age, climate, country, socioeconomic status, and other factors, approximately 10% of the human population harbors meningococci in the nose. However, invasive disease is relatively rare, as it occurs only when the following conditions are fulfilled: (i) contact with a virulent strain, (ii) colonization by that strain, (iii) penetration of the bacterium through the mucosa, and (iv) survival and eventually outgrowth of the meningococcus in the bloodstream. When the meningococcus has reached the bloodstream and specific antibodies are absent, as is the case for young children or after introduction of a new strain in a population, the ultimate outgrowth depends on the efficacy of the innate immune response. Massive outgrowth leads within 12 h to fulminant meningococcal sepsis (FMS), characterized by high intravascular concentrations of endotoxin that set free high concentrations of proinflammatory mediators. These mediators belonging to the complement system, the contact system, the fibrinolytic system, and the cytokine system induce shock and diffuse intravascular coagulation. FMS can be fatal within 24 h, often before signs of meningitis have developed. In spite of the increasing possibilities for treatment in intensive care units, the mortality rate of FMS is still 30%. When the outgrowth of meningococci in the bloodstream is impeded, seeding of bacteria in the subarachnoidal compartment may lead to overt meningitis within 24 to 36 h. With appropriate antibiotics and good clinical surveillance, the mortality rate of this form of invasive disease is 1 to 2%. The overall mortality rate of meningococcal disease can only be reduced when patients without meningitis, i.e., those who may develop FMS, are recognized early. This means that the fundamental nature of the disease as a meningococcus septicemia deserves more attention.

Nitric oxide participates in the immune response against Neisseria meningitidis serogroup B

The present report explores the role of nitric oxide into the immune response against Neisseria meningitidis serogroup B. Here we show that NO mediates the alphaTNF increase induced by N. meningitidis derived lipopolysaccharides (LPS), at the same time that participates in the bactericidal activity of resting or gammaIFN activated macrophages and plays a role in the specific DTH and IgG response induced by a commercial anti-meningococcal vaccine. Our findings suggest a positive role for NO at the final effector mechanisms and in the early events driving the immunity against N. meningitidis, suggesting also an insight into its role in endotoxic shock.

Circulating platelet-neutrophil complexes represent a subpopulation of activated neutrophils primed for adhesion, phagocytosis and intracellular killing

Platelets play a prominent role in linking the processes of inflammation, haemostasis and thrombosis. Recent studies have shown that platelets form heterotypic aggregates with leucocytes via platelet CD62P and leucocyte beta2 integrins. These interactions have been observed in vitro in blood taken from healthy volunteers and in clinical conditions in which thrombosis and inflammation are prominent. This study investigated the properties of platelet-neutrophil complexes (PNCs) in anticoagulated whole blood. At rest, neutrophils in PNCs exhibit a significantly more activated adhesion molecule profile than free neutrophils with increased CD11b expression and activation (increased binding of the CD11b/CD18 'activation reporter' monoclonal antibody 24) and decreased CD62L expression. In addition, neutrophils in PNCs phagocytosed significantly more Neisseria meningitidis and produced more toxic oxygen metabolites than free neutrophils. Stimulation with the platelet agonist adenosine diphosphate (ADP) led to further increases in CD11b expression and activation, loss of CD62L as well as increased phagocytosis and toxic oxygen metabolite production throughout the whole neutrophil population. When these experiments were repeated with the CD62P blocking antibody G1 the effects were inhibited to a variable extent, dependent upon the parameter under investigation. These results indicate that both soluble and contact-dependent factors contribute to platelet-mediated neutrophil activation. Platelet neutrophil complexes represent a large subpopulation of neutrophils with a more activated adhesion molecule profile, and a greater capacity for phagocytosis and toxic oxygen metabolite production. This study provides further support for a role for PNCs in both health and disease.