Pathophysiology of Pediatric Multiple Organ Dysfunction Syndrome

Lipopolysaccharide (LPS)-Induced Tumor Necrosis Factor-Alpha (TNF-ɑ) Levels and Health Care Associated Infection (HAI) in Children with Multi-Organ Dysfunction Syndrome (MODS)

The present study estimated lipopolysaccharide (LPS)-induced tumor necrosis factor-alpha (TNF-α) levels and its association with health care associated infection (HAI) and duration of multi-organ dysfunction syndrome (MODS). LPS-induced TNF-α levels were estimated in 67 children on day 3 of MODS. Variables recorded were Pediatric Index of Mortality (PIM-3), cultures, diagnosis, HAI, days of MODS, survivors and non-survivors. Of 67 children, 37 (52.2%) were male and 27 (40.2%) expired. Sixty-three (94%) children had reduced TNF-α levels (<200 pg/ml); 23.11 (10.38, 40.59). The median number of days in MODS was 7 (5, 12) and prolonged MODS (≥7 d) was observed in 49/67 (73.1%) children. Forty-five (67.1%) children had HAI, among these 33/45 (73.3%) had ventilator associated pneumonia (VAP). TNF-α levels were significantly lower in children with MODS, prolonged MODS, children who developed HAI and non-survivors as compared to healthy children (p <0.0001), children with MODS <7 d (p=0.01), children without HAI (p=0.009) and survivors (p=0.04), respectively. HAI was independently associated with reduced levels of TNF-α (p=0.01).

Evaluation of the Performance of Various Diagnostic Modalities Available for the Detection of Scrub Typhus in Acute Undifferentiated Febrile Illness (AUFI) Cases at a Teaching Hospital in North Chhattisgarh, India

INTRODUCTION

Due to the lack of adequate data on the effectiveness of diagnostic methods and the ambiguous clinical symptoms that overlap with other febrile illnesses, diagnosing scrub typhus is difficult. This study aims to compare the accuracy of various investigations required for the diagnosis of scrub typhus like immunoglobulin G/immunoglobulin M (IgG/IgM) rapid test, IgM enzyme-linked immunosorbent assay (ELISA), and real-time polymerase chain reaction (RT-PCR) from a patient's serum.

METHODS

This is a prospective study that includes all clinically suspected patients who visited the Outpatient Department (OPD) of Medicine and were admitted to the Medicine wards and Intensive Care Units of Rajmata Shrimati Devendra Kumari Singhdeo Government Medical College, Ambikapur, Chhattisgarh, India. The patients' samples were tested initially using the IgG/IgM rapid test, further confirmed by ELISA, and then subjected to RT-PCR for final confirmation.

RESULTS

A total of 1,620 cases of acute undifferentiated febrile illness were tested, of which 82 tested positive for scrub typhus IgM rapid test. These 82 cases were further tested for confirmation using IgM ELISA, which showed 110 positive results. Additionally, RT-PCR was applied to all 1,620 samples using the DIAGsure Tropical Fever Panel Kit (3B BlackBio Dx Limited, Bhopal, India), resulting in 98 samples testing positive for scrub typhus. Both the ELISA and the rapid diagnostic test offer high capacity for discrimination, with sensitivity and specificity of 92.40%, 93.18%, and 99.20%, 98.17%, respectively (10.9% of cases came positive in serology which was negative in RT-PCR). It can be due to its nonspecific binding with antibodies of other febrile illnesses such as malaria, enteric fever, pulmonary tuberculosis, leptospirosis, etc. Conclusion: RT-PCR has shown excellent results with a sensitivity of >95% and specificity of >99%. Given its high sensitivity and specificity, along with clinical findings, RT-PCR is highly effective in detecting scrub typhus, especially for diagnosing early stages of the disease in cases of acute febrile illness with a duration of less than seven days. In reference labs, RT-PCR is the primary method for confirmation. This paper offers a thorough assessment of all the diagnostic tests for scrub typhus that are now accessible in a setting with limited resources, such as our north Chhattisgarh region.

Age influences the circulating immune profile in pediatric sepsis

Background

The immune response changes as patients age, yet studies on the immune dysregulation of sepsis often do not consider age as a key variable.

Objective

We hypothesized that age would influence the immune response in septic children and that there would be a distinct variation in the immune profile in healthy children and children with either sepsis, uncomplicated infection, or acute organ dysfunction without infection. We characterized the circulating immune profile of children presenting to our tertiary care children's hospital.

Methods

This investigation was a prospective, observational cohort study that enrolled patients from July 2020 - September 2022. Patients were included if they were < 21 years, admitted to the PICU, and received fluid resuscitation and antibiotics. Peripheral blood mononuclear cells were isolated from samples collected on PICU day 1.

Results

Eighty patients were enrolled. Children with sepsis had more regulatory CD4+ T cells and memory CD4+ T cells and less CD4+IL-10+ and CD8+T-bet+ T cells than healthy children. After ex vivo stimulation, sepsis samples had less of a reduction in CD4+ T cells producing IL-10 than healthy controls. Memory CD4+ T cells and regulatory CD4+ T cells were positively associated with age in sepsis alone.

Conclusion

A regulatory T cell failure may contribute to pediatric sepsis pathogenesis. Age is an important variable affecting sepsis-associated immune dysregulation and memory T cells in peripheral circulation correlate with age in sepsis alone.

Dysregulated STAT3 signaling and T cell immunometabolic dysfunction define a targetable, high mortality subphenotype of critically ill children

Sepsis is the leading cause of death of hospitalized children worldwide. Despite the established link between immune dysregulation and mortality in pediatric sepsis, it remains unclear which host immune factors contribute causally to adverse sepsis outcomes. Identifying modifiable pathobiology is an essential first step to successful translation of biologic insights into precision therapeutics. We designed a prospective, longitudinal cohort study of 88 critically ill pediatric patients with multiple organ dysfunction syndrome (MODS), including patients with and without sepsis, to define subphenotypes associated with targetable mechanisms of immune dysregulation. We first assessed plasma proteomic profiles and identified shared features of immune dysregulation in MODS patients with and without sepsis. We then employed consensus clustering to define three subphenotypes based on protein expression at disease onset and identified a strong association between subphenotype and clinical outcome. We next identified differences in immune cell frequency and activation state by MODS subphenotype and determined the association between hyperinflammatory pathway activation and cellular immunophenotype. Using single cell transcriptomics, we demonstrated STAT3 hyperactivation in lymphocytes from the sickest MODS subgroup and then identified an association between STAT3 hyperactivation and T cell immunometabolic dysregulation. Finally, we compared proteomics findings between patients with MODS and patients with inborn errors of immunity that amplify cytokine signaling pathways to further assess the impact of STAT3 hyperactivation in the most severe patients with MODS. Overall, these results identify a potentially pathologic and targetable role for STAT3 hyperactivation in a subset of pediatric patients with MODS who have high severity of illness and poor prognosis.

Multiorgan Dysfunction Syndrome in Abusive and Accidental Pediatric Traumatic Brain Injury

BACKGROUND

Abusive head trauma (AHT) is a mechanism of pediatric traumatic brain injury (TBI) with high morbidity and mortality. Multiorgan dysfunction syndrome (MODS), defined as organ dysfunction in two or more organ systems, is also associated with morbidity and mortality in critically ill children. Our objective was to compare the frequency of MODS and evaluate its association with outcome between AHT and accidental TBI (aTBI).

METHODS

This was a single center, retrospective cohort study including children under 3 years old admitted to the pediatric intensive care unit with nonpenetrating TBI between 2014 and 2021. Presence or absence of MODS on days 1, 3, and 7 using the Pediatric Logistic Organ Dysfunction-2 score and new impairment status (Functional Status Scale score change > 1 compared with preinjury) at hospital discharge (HD), short-term timepoint, and long-term timepoint were abstracted from the electronic health record. Multiple logistic regression was performed to examine the association between MODS and TBI mechanism with new impairment status.

RESULTS

Among 576 children, 215 (37%) had AHT and 361 (63%) had aTBI. More children with AHT had MODS on days 1 (34% vs. 23%, p = 0.003), 3 (28% vs. 6%, p < 0.001), and 7 (17% vs. 3%, p < 0.001) compared with those with aTBI. The most common organ failures were cardiovascular ([AHT] 66% vs. [aTBI] 66%, p = 0.997), neurologic (33% vs. 16%, p < 0.001), and respiratory (34% vs. 15%, p < 0.001). MODS was associated with new impairment in multivariable logistic regression at HD (odds ratio 19.1 [95% confidence interval 9.8-38.6, p < 0.001]), short-term discharge (7.4 [3.7-15.2, p < 0.001]), and long-term discharge (4.3 [2.0-9.4, p < 0.001])]. AHT was also associated with new impairment at HD (3.4 [1.6-7.3, p = 0.001]), short-term discharge (2.5 [1.3-4.7, p = 0.005]), and long-term discharge (2.1 [1.1-4.1, p = 0.036]).

CONCLUSIONS

Abusive head trauma as a mechanism was associated with MODS following TBI. Both AHT mechanism and MODS were associated with new impairment at all time points.

Programmed Cell Death Protein-1 Regulation in Response to SARS-CoV-2 in Paediatric Multisystem Inflammatory Syndrome Temporally Associated with SARS-CoV-2: A Prospective Cohort Study

The role of programmed death cell protein 1 (PD-1) has already been described in a range of various diseases, including COVID-19. This study provides new, innovative data, related to the expression of PD-1 and the risk of Paediatric Inflammatory Multisystem Syndrome, temporally associated with SARS-CoV-2 infection (PIMS-TS)-a rare, but potentially life-threatening complication of COVID-19. In this study, we evaluated the expression of PD-1 protein in patients with PIMS. Blood samples were taken from patients at the time of diagnosis (n = 33), after 6 weeks (n = 33), 3 months (n = 24), 6 months (n = 24) and 12 months (n = 8). The immunophenotypes were evaluated in flow cytometry. The control group consisted of 35 healthy children with negative SARS-CoV-2 antigen/PCR test, who were asymptomatic and had no history of allergic, autoimmune or oncological diseases. The associations between immunophenotypes, biochemical findings and clinical data were analysed. Significant increases in the expression of PD-1 for CD4+ and CD8+ T cells, compared to the control group, were observed in the day of admission, with a gradual decrease during the first weeks from initiation of treatment. This study sheds new light on the pathogenesis of PIMS-TS, emphasizing the role of PD-1 protein. Future research is essential for early risk prediction in SARS-CoV-2 patients and for devising effective clinical prevention and management strategies.

Persistent Inflammation, Immunosuppression, and Catabolism Syndrome in Pediatric Populations: A Brief Perspective

Surviving near-lethal insults, such as sepsis, trauma, and major surgery is more common due to advances in medical care. The decline in mortality has unmasked a population of chronic critically ill patients, many with the pathological immunophenotype known as Persistent inflammation, Immunosuppression, and Catabolism Syndrome (PICS). Though initially described in adults, many critically ill children exhibit the hallmarks of PICS, including lymphopenia, hyperinflammation, and evidence of ongoing somatic protein catabolism. These patients are plagued with recurrent infections and suffer worse outcomes. There remains a need to understand the pathophysiology underlying this condition to elucidate potential therapies and develop interventions. This perspective provides the most current update of PICS within the pediatric population.

SERUM HUMANIN IN PEDIATRIC SEPTIC SHOCK-ASSOCIATED MULTIPLE-ORGAN DYSFUNCTION SYNDROME

ABSTRACT

Background: Multiple-organ dysfunction syndrome disproportionately contributes to pediatric sepsis morbidity. Humanin (HN) is a small peptide encoded by mitochondrial DNA and thought to exert cytoprotective effects in endothelial cells and platelets. We sought to test the association between serum HN (sHN) concentrations and multiple-organ dysfunction syndrome in a prospectively enrolled cohort of pediatric septic shock. Methods: Human MT-RNR2 ELISA was used to determine sHN concentrations on days 1 and 3. The primary outcome was thrombocytopenia-associated multiorgan failure (TAMOF). Secondary outcomes included individual organ dysfunctions on day 7. Associations across pediatric sepsis biomarker (PERSEVERE)-based mortality risk strata and correlation with platelet and markers of endothelial activation were tested. Results: One hundred forty subjects were included in this cohort, of whom 39 had TAMOF. The concentration of sHN was higher on day 1 relative to day 3 and among those with TAMOF phenotype in comparison to those without. However, the association between sHN and TAMOF phenotype was not significant after adjusting for age and illness severity in multivariate models. In secondary analyses, sHN was associated with presence of day 7 sepsis-associated acute kidney injury ( P = 0.049). Furthermore, sHN was higher among those with high PERSEVERE-mortality risk strata and correlated with platelet counts and several markers of endothelial activation. Conclusion: Future investigation is necessary to validate the association between sHN and sepsis-associated acute kidney injury among children with septic shock. Furthermore, mechanistic studies that elucidate the role of HN may lead to therapies that promote organ recovery through restoration of mitochondrial homeostasis among those critically ill.

Machine learning-driven identification of the gene-expression signature associated with a persistent multiple organ dysfunction trajectory in critical illness

BACKGROUND

Multiple organ dysfunction syndrome (MODS) disproportionately drives morbidity and mortality among critically ill patients. However, we lack a comprehensive understanding of its pathobiology. Identification of genes associated with a persistent MODS trajectory may shed light on underlying biology and allow for accurate prediction of those at-risk.

METHODS

Secondary analyses of publicly available gene-expression datasets. Supervised machine learning (ML) was used to identify a parsimonious set of genes associated with a persistent MODS trajectory in a training set of pediatric septic shock. We optimized model parameters and tested risk-prediction capabilities in independent validation and test datasets, respectively. We compared model performance relative to an established gene-set predictive of sepsis mortality.

FINDINGS

Patients with a persistent MODS trajectory had 568 differentially expressed genes and characterized by a dysregulated innate immune response. Supervised ML identified 111 genes associated with the outcome of interest on repeated cross-validation, with an AUROC of 0.87 (95% CI: 0.85-0.88) in the training set. The optimized model, limited to 20 genes, achieved AUROCs ranging from 0.74 to 0.79 in the validation and test sets to predict those with persistent MODS, regardless of host age and cause of organ dysfunction. Our classifier demonstrated reproducibility in identifying those with persistent MODS in comparison with a published gene-set predictive of sepsis mortality.

INTERPRETATION

We demonstrate the utility of supervised ML driven identification of the genes associated with persistent MODS. Pending validation in enriched cohorts with a high burden of organ dysfunction, such an approach may inform targeted delivery of interventions among at-risk patients.

FUNDING

H.R.W.'s NIHR35GM126943 award supported the work detailed in this manuscript. Upon his death, the award was transferred to M.N.A. M.R.A., N.S.P, and R.K were supported by NIHR21GM151703. R.K. was supported by R01GM139967.

COVID-19 illness: Different comorbidities may require different immunological therapeutic targets

BACKGROUND

The SARS-CoV-2 pandemic has led to more than 6,870.000 deaths worldwide. Despite recent therapeutic advances, deaths in Intensive Care Units still range between 34 and 72%, comprising substantial unmet need as we move to an endemic phase. The general agreement is that in the first few days of infection, antiviral drugs and neutralizing monoclonal antibodies should be adopted. When the patient is hospitalized and develops severe pneumonia, progressing to a systemic disease, immune modifying therapy with corticosteroids is indicated. Such interventions, however, are less effective in the context of comorbidities (e.g., diabetes, hypertension, heart failure, atrial fibrillation, obesity and central nervous system-CNS diseases) which are by themselves associated with poor outcomes. Such comorbidities comprise common and some distinct underlying inflammatory pathobiology regulated by differential cytokine taxonomy.

METHODS

Searching in the PubMed database, literature pertaining to the biology underlying the different comorbidities, and the data from the studies related to various immunological treatments for the Covid-19 disease were carefully analyzed.

RESULTS

Several experimental and clinical data have demonstrated that hypertension and atrial fibrillation present an IL-6 dependent signature, whereas diabetes, obesity, heart failure and CNS diseases may exhibit an IL-1a/b predominant signature. Distinct selective cytokine targeting may offer advantage in treating severe COVID-19 illness based on single or multiple associated comorbidities. When the patient does not immediately respond, a broader target range through JAKs pathway inhibitors may be indicated.

CONCLUSIONS

Herein, we discuss the biological background associated with distinct comorbidities which might impact the SARS-CoV-2 infection course and how these should to be addressed to improve the current therapeutic outcome.

Neutrophils and the Systemic Inflammatory Response Syndrome (SIRS)

We are not entirely able to understand, assess, and modulate the functioning of the immune system in clinical situations that lead to a systemic inflammatory response. In the search for diagnostic and treatment strategies (which are still far from perfect), it became very important to study the pathogenesis and participation of endogenous inflammation mediators. This study attempts to more precisely establish the role of neutrophils in individual phenomena occurring during an inflammatory and anti-inflammatory reaction, taking into account their cidal, immunoregulatory, and reparative abilities. Pro- and anticoagulatory properties of endothelium in systemic inflammatory response syndrome (SIRS) are emphasised, along with the resulting clinical implications (the application of immunotherapy using mesenchymal stem/stromal cells (MSCs) or IL-6 antagonists in sepsis and COVID-19 treatment, among others). Special attention is paid to reactive oxygen species (ROS), produced by neutrophils activated during "respiratory burst" in the course of SIRS; the protective and pathogenic role of these endogenous mediators is highlighted. Moreover, clinically useful biomarkers of SIRS (neutrophil extracellular traps, cell-free DNA, DAMP, TREMs, NGAL, miRNA, selected cytokines, ROS, and recognised markers of endothelial damage from the group of adhesins by means of immunohistochemical techniques) related to the neutrophils are presented, and their role in the diagnosing and forecasting of sepsis, burn disease, and COVID-19 is emphasised. Finally, examples of immunomodulation of sepsis and antioxidative thermal injury therapy are presented.

Near-fatal cocaine intoxication in an infant with thrombotic microangiopathy associated with multiple organ failure

OBJECTIVE

To report a pediatric case of drug-induced thrombotic microangiopathy caused by cocaine.

CASE DESCRIPTION

We report a nine-month-old patient who developed thrombotic microangiopathies after extreme cocaine intoxication, multiple organ dysfunction syndrome with hemodynamic dysfunction, anuric renal failure, liver failure, encephalopathy, and myocardial injury, corresponding phenotypically to thrombocytopenia-associated multiple organ failure. The patient received continuous venous hemofiltration and therapeutic plasma exchange, recovering satisfactorily. She was discharged after 30 days of hospitalization under the guidance of the childcare service, and was healthy after one year of follow-up. Toxicological samples confirmed high levels of cocaine and derivatives in blood, urine and hair.

COMMENTS

To our knowledge, this is the first reported pediatric case. There are particularities of cocaine intoxication pathophysiology that can trigger thrombotic microangiopathies because of vasoconstriction, direct endothelial injury, platelet activation, and increasing von Willebrand factor and fibrinogen levels. All of which results in a prothrombotic state, inflammatory dysregulation, and microvascular thrombi. The increasing use of cocaine, especially among young adults, puts children at high risk of toxicity, either by passive unintentional exposure, or abuse due to the increased availability in homes.

Pediatric Swine Model of Methicillin-Resistant Staphylococcus aureus Sepsis-Induced Coagulopathy, Disseminated Microvascular Thrombosis, and Organ Injuries

Sepsis-induced coagulopathy leading to disseminated microvascular thrombosis is associated with high mortality and has no existing therapy. Despite the high prevalence of Gram-positive bacterial sepsis, especially methicillin-resistant Staphylococcus aureus (MRSA), there is a paucity of published Gram-positive pediatric sepsis models. Large animal models replicating sepsis-induced coagulopathy are needed to test new therapeutics before human clinical trials.

HYPOTHESIS

Our objective is to develop a pediatric sepsis-induced coagulopathy swine model that last 70 hours.

METHODS AND MODELS

Ten 3 weeks old piglets, implanted with telemetry devices for continuous hemodynamic monitoring, were IV injected with MRSA (n = 6) (USA300, Texas Children's Hospital 1516 strain) at 1 × 109 colony forming units/kg or saline (n = 4). Fluid resuscitation was given for heart rate greater than 50% or mean arterial blood pressure less than 30% from baseline. Acetaminophen and dextrose were provided as indicated. Point-of-care complete blood count, prothrombin time (PT), activated thromboplastin time, d-dimer, fibrinogen, and specialized coagulation assays were performed at pre- and post-injection, at 0, 24, 48, 60, and 70 hours. Piglets were euthanized and necropsies performed.

RESULTS

Compared with the saline treated piglets (control), the septic piglets within 24 hours had significantly lower neurologic and respiratory scores. Over time, PT, d-dimer, and fibrinogen increased, while platelet counts and activities of factors V, VII, protein C, antithrombin, and a disintegrin and metalloproteinase with thrombospondin-1 motifs (13th member of the family) (ADAMTS-13) decreased significantly in septic piglets compared with control. Histopathologic examination showed minor focal organ injuries including microvascular thrombi and necrosis in the kidney and liver of septic piglets.

INTERPRETATIONS AND CONCLUSIONS

We established a 70-hour swine model of MRSA sepsis-induced coagulopathy with signs of consumptive coagulopathy, disseminated microvascular thrombosis, and early organ injuries with histological minor focal organ injuries. This model is clinically relevant to pediatric sepsis and can be used to study dysregulated host immune response and coagulopathy to infection, identify potential early biomarkers, and to test new therapeutics.

Immunoparalysis in critically ill children

Immunoparalysis is associated with poorer outcomes in the paediatric intensive care unit (PICU) setting. We aimed to determine the group of patients with higher chances of immunoparalysis and correlate this status with increased risks of nosocomial infection and adverse clinical parameters. We conducted an exploratory study with prospective data collection in a university-affiliated tertiary medical, surgical, and cardiac PICU. Fifteen patients with multiple organ dysfunction syndrome were included over a period of 6 months. Monocyte's human leucocyte antigen (HLA)-DR expression and tumour necrosis factor (TNF)-α and interleukin (IL)-6 production were measured by flow-cytometry at three time points (T1 = 1-2 days; T2 = 3-5 days; T3 = 6-8 days). Using the paediatric logistic organ dysfunction-2 score to assess initial disease severity, we established the optimal cut-off values of the evaluated parameters to identify the subset of patients with a higher probability of immunoparalysis. A comparative analysis was performed between them. Sixty per cent were males; the median age was 4.1 years. Considering the presence of two criteria in T1 (classical monocytes mean fluorescence intensity [MFI] for HLA-DR ≤ 1758.5, area under the curve (AUC) = 0.775; and frequency of monocytes producing IL-6 ≤ 68.5%, AUC = 0.905) or in T3 (classical monocytes MFI of HLA-DR ≤ 2587.5, AUC = 0.675; and frequency of monocytes producing TNF-α ≤ 93.5%, AUC = 0.833), a variable to define immunoparalysis was obtained (100% sensitivity, 81.5% specificity). Forty per cent of patients were assigned to the immunoparalysis group. In this: a higher frequency of nosocomial infection (p = 0.011), vasoactive inotropic score (p = 0.014) and length of hospital stay (p = 0.036) was observed. In the subgroup with the diagnosis of sepsis/septic shock (n = 5), patients showed higher percentages of non-classical monocytes (p = 0.004). No mortality was recorded. A reduction in classical monocytes HLA-DR expression with lower frequencies of monocytes producing TNF-α and IL-6 during the first week of critical illness, appears to be a good marker of immunoparalysis; these findings relate to an increased risk of nosocomial infection and deleterious outcomes. The increased frequency of non-classical monocytes in patients with sepsis/septic shock is suggestive of a better prognosis.

Pathogenesis, Prognosis and Outcomes of Multiple Organ Failure in Newborns (Review)

Multiple organ failure (MOF) is the leading cause of neonatal mortality in intensive care units. The prevalence of MOF in newborns is currently unclear, since its incidence varies in asphyxia, sepsis, prematurity, and comorbidity, and depends on the level of development and funding of health care in different countries. Sepsis and acute respiratory distress syndrome prevail among the causes of MOF in this category of patients.

Aim of the review. To summarize the available literature data on the pathogenesis, therapeutic strategies and outcomes of MOF in newborns.

Material and methods. We searched PubMed, Scopus, Web of Science, and RSCI databases using the following keywords: «newborns, multiple organ failure, etiology, pathogenesis, premature, diagnosis, treatment, respiratory support, cardiotonic support», without language limitations. A total of 144 full-text sources were selected for analysis, 70% of which were published in the last five years and 50% were published in the last three years. Criteria for exclusion were low information value and outdated data.

Results. The prevalence of MOF in neonates is currently unclear. This could be due to common association of neonatal MOF (as well as the adult one) with various diseases; thus, its incidence is not the same for asphyxia, sepsis, prematurity, and comorbidities. There is no precise data on neonatal mortality in MOF, but according to some reports, it may be as high as 13-50%.

In newborns, MOF can be caused by two major causes, intrapartum/postnatal asphyxia and sepsis, but could also be influenced by other intranatal factors such as intrauterine infections and acute interruption of placental blood flow.

The key element in the pathogenesis of neonate MOF is cytokinemia, which triggers universal critical pathways. Attempts to identify different clinical trajectories of critical illness in various categories of patients have led to the discovery of MOF phenotypes with specific patterns of systemic inflammatory response. This scientific trend is very promising for the creation of new classes of drugs and individual therapeutic pathways in neonates with MOF of various etiologies.

The pSOFA scale is used to predict the outcome of neonatal MOF, however, the nSOFA scale has higher validity in premature infants with low birth weight.

Central nervous system damage is the major MOF-associated adverse outcome in newborns, with gestational age and the timing of treatment initiation being key factors affecting risk of MOF development in both full-term and premature infants.

Conclusion. The study of cellular messengers of inflammation, MOF phenotypes, mitochondrial insufficiency, and immunity in critically ill infants with MOF of various etiologies is a promising area of research. The pSOFA scale is suggested for predicting the outcome of MOF in full-term infants, while the nSOFA scale should be used in premature infants with low birth weight.

Integrated PERSEVERE and endothelial biomarker risk model predicts death and persistent MODS in pediatric septic shock: a secondary analysis of a prospective observational study

Background

Multiple organ dysfunction syndrome (MODS) is a critical driver of sepsis morbidity and mortality in children. Early identification of those at risk of death and persistent organ dysfunctions is necessary to enrich patients for future trials of sepsis therapeutics. Here, we sought to integrate endothelial and PERSEVERE biomarkers to estimate the composite risk of death or organ dysfunctions on day 7 of septic shock.

Methods

We measured endothelial dysfunction markers from day 1 serum among those with existing PERSEVERE data. TreeNet® classification model was derived incorporating 22 clinical and biological variables to estimate risk. Based on relative variable importance, a simplified 6-biomarker model was developed thereafter.

Results

Among 502 patients, 49 patients died before day 7 and 124 patients had persistence of MODS on day 7 of septic shock. Area under the receiver operator characteristic curve (AUROC) for the newly derived PERSEVEREnce model to predict death or day 7 MODS was 0.93 (0.91–0.95) with a summary AUROC of 0.80 (0.76–0.84) upon tenfold cross-validation. The simplified model, based on IL-8, HSP70, ICAM-1, Angpt2/Tie2, Angpt2/Angpt1, and Thrombomodulin, performed similarly. Interaction between variables—ICAM-1 with IL-8 and Thrombomodulin with Angpt2/Angpt1—contributed to the models’ predictive capabilities. Model performance varied when estimating risk of individual organ dysfunctions with AUROCS ranging from 0.91 to 0.97 and 0.68 to 0.89 in training and test sets, respectively.

Conclusions

The newly derived PERSEVEREnce biomarker model reliably estimates risk of death or persistent organ dysfunctions on day 7 of septic shock. If validated, this tool can be used for prognostic enrichment in future pediatric trials of sepsis therapeutics.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04070-5.

Mortality Risk in Pediatric Sepsis Based on C-reactive Protein and Ferritin Levels

OBJECTIVES

Interest in using bedside C-reactive protein (CRP) and ferritin levels to identify patients with hyperinflammatory sepsis who might benefit from anti-inflammatory therapies has piqued with the COVID-19 pandemic experience. Our first objective was to identify patterns in CRP and ferritin trajectory among critically ill pediatric sepsis patients. We then examined the association between these different groups of patients in their inflammatory cytokine responses, systemic inflammation, and mortality risks.

DATA SOURCES

A prospective, observational cohort study.

STUDY SELECTION

Children with sepsis and organ failure in nine pediatric intensive care units in the United States.

DATA EXTRACTION

Two hundred and fifty-five children were enrolled. Five distinct clinical multi-trajectory groups were identified. Plasma CRP (mg/dL), ferritin (ng/mL), and 31 cytokine levels were measured at two timepoints during sepsis (median Day 2 and Day 5). Group-based multi-trajectory models (GBMTM) identified groups of children with distinct patterns of CRP and ferritin.

DATA SYNTHESIS

Group 1 had normal CRP and ferritin levels ( n = 8; 0% mortality); Group 2 had high CRP levels that became normal, with normal ferritin levels throughout ( n = 80; 5% mortality); Group 3 had high ferritin levels alone ( n = 16; 6% mortality); Group 4 had very high CRP levels, and high ferritin levels ( n = 121; 11% mortality); and Group 5 had very high CRP and very high ferritin levels ( n = 30; 40% mortality). Cytokine responses differed across the five groups, with ferritin levels correlated with macrophage inflammatory protein 1α levels and CRP levels reflective of many cytokines.

CONCLUSIONS

Bedside CRP and ferritin levels can be used together to distinguish groups of children with sepsis who have different systemic inflammation cytokine responses and mortality risks. These data suggest future potential value in personalized clinical trials with specific targets for anti-inflammatory therapies.

Vascular Reactivity Index and PELOD-2 as a mortality predictor in paediatric septic shock: a single-centre retrospective study

BACKGROUND

The mortality rate for children with septic shock is stil quite high in low-income and middle-income countries (31.7%). One of the most widely used scoring systems to assess mortality in sepsis or septic shock is Paediatric Logistic Organ Dysfunction 2 (PELOD-2). However, it requires various laboratory evaluations. A non-invasive, fast and easy method is needed to assess the mortality of children with septic shock at an early stage. Therefore, this study aims to evaluate the ability of Vascular Reactivity Index (VRI) compared with PELOD-2 score as a predictor of mortality in children with septic shock based on vascular response to vasoactive agents.

METHODS

A retrospective cohort study was conducted using data from children aged 1 month to 18 years with septic shock treated in the ER and paediatric intensive care unit (PICU) of the tertiary hospital from 2017 to 2021. The serial haemodynamic data were analysed including Systemic Vascular Resistant Index (SVRI) and the cardiac index from ultrasound cardiac output monitoring device was recorded in the first and sixth hours after the diagnosis of septic shock. The VRI was determined by dividing SVRI/Vasoactive Inotropic Score (ie, accumulated doses of dopamine, dobutamine, epinephrine, milrinone, vasopressin and norepinephrine). The receiver operating curve was used to calculate the area under the curve (AUC), sensitivity and specificity of each cut-off point.

RESULTS

A total of 68 subjects fulfilled the inclusion and exclusion criteria, the median age was 54 months with a range of 2-204 months and the mortality rate was 47%. The majority of the patients who died were found in the high cardiac index and low SVRI group (17.6%). Moreover, the optimum cut-off point of VRI was obtained to predict mortality in septic shock of 32.1, with 87.5% sensitivity and 88.9% specificity. The AUC for predicting death using VRI was 95% (95% CI 90% to 100%, p<0.001) and PELOD-2 92.6% (95% CI 96.4% to 98.8%, p<0.001).

CONCLUSION

The VRI <32.1 may potentially be used to predict mortality in children with septic shock and its predictive ability is as good as PELOD-2. The assessment of VRI is faster and easier than PELOD-2.

Case series: Factors of mortality in pediatric patients with pelvic fractures

OBJECTIVE

No algorithm exists to guide the orthopedic treatment of pediatric patients with pelvic fractures, as most analytic studies have been conducted in adults. The goal of this study was to identify prognostic factors of pelvic fractures, and suggest whether early total care can be safely provided.

METHODS

A retrospective trauma database for pediatric pelvic fractures from 2002-2018 was gathered, and patient charts were reviewed.

RESULTS

A total of 128 patients were evaluated for pelvic trauma; 99 injuries were secondary to motor vehicle accidents (MVA) (77%), and 19 were secondary to falls (15%). Patients were more likely to be male (71%), older (33% aged 15-16 years, 2% aged 0-1 years), to experience a head trauma (55%), to be treated conservatively (70%), and to survive their trauma (91%). About half of the patients (49%) experienced an additional extremity trauma. When exploring the prognostic factors, mortality was associated with thoracic trauma (72% vs. 27%, p<0.05); a lower reduction of neutrophils levels 48 hours after the initial trauma (-1.34 vs. -7.7, p<0.05); a more significant reduction upon arrival of Prothrombin Time (72% vs. 37%, p<0.01), and an increment of International Normalized Ratio (2.29 vs. 1.26, p<0.01) and Partial Thromboplastin Time (79 vs 28, p<0.01). There was also a higher demand for Fresh Frozen Plasma (24% vs. 9%, p<0.05); Upon presentation, there was a higher Injury Severity Score (49 vs. 21, p<0.001), and a lower systolic Blood Pressure (96 vs. 118, p<0.05); The deceased did not have a very prolonged stay in the hospital (3 days vs. 12 days, P<0.01); Mortality was not significantly associated with either Early Total Care or Damage Control Orthopedics.

CONCLUSIONS

Prognostic factors in pediatric patients with pelvic fractures parallel those of the adult population. Pediatric patients tendentiously outlive their pelvic trauma, whether the course of action taken by their surgeons is Conservative by nature, Early Total Care or Damage Control Orthopedics.

Association Between Heart Rate Variability and Inflammatory Biomarkers in Critically Ill Children

OBJECTIVES

The autonomic nervous system (ANS) can both modulate and be modulated by the inflammatory response during critical illness. We aimed to determine whether heart rate variability (HRV), a measure of ANS function, is associated with proinflammatory biomarker levels in critically ill children.

DESIGN

Two cohorts were analyzed. The first was a prospective observational cohort from August 2018 to August 2020 who had plasma proinflammatory cytokine measurements within 72 hours of admission, including tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and IL-8. The second was a retrospective cohort from June 2012 to August 2020 who had at least one C-reactive protein (CRP) measurement within 72 hours of admission.

SETTING

Forty-six-bed PICU.

PATIENTS

Critically ill children in either cohort who had continuous heart rate data available from the bedside monitors.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Sixty-two patients were included in the prospective cohort and 599 patients in the retrospective cohort. HRV was measured using the age-adjusted integer heart rate variability (HRVi), which is the sd of the heart rate sampled every 1 second over 5 consecutive minutes. The median HRVi was measured in the 12-hour period ending 30 minutes prior to inflammatory biomarker collection. HRVi was inversely correlated with IL-6, IL-8, and CRP levels (p ≤ 0.02); correlation with IL-8 and CRP persisted after adjusting for Pediatric Risk of Mortality III and age, and median HR and age (p < 0.001).

CONCLUSIONS

HRVi is inversely correlated with IL-6, IL-8, and CRP. Further studies are needed to validate this measure as a proxy for a proinflammatory state.

Machine learning derivation of four computable 24-h pediatric sepsis phenotypes to facilitate enrollment in early personalized anti-inflammatory clinical trials

BACKGROUND

Thrombotic microangiopathy-induced thrombocytopenia-associated multiple organ failure and hyperinflammatory macrophage activation syndrome are important causes of late pediatric sepsis mortality that are often missed or have delayed diagnosis. The National Institutes of General Medical Science sepsis research working group recommendations call for application of new research approaches in extant clinical data sets to improve efficiency of early trials of new sepsis therapies. Our objective is to apply machine learning approaches to derive computable 24-h sepsis phenotypes to facilitate personalized enrollment in early anti-inflammatory trials targeting these conditions.

METHODS

We applied consensus, k-means clustering analysis to our extant PHENOtyping sepsis-induced Multiple organ failure Study (PHENOMS) dataset of 404 children. 24-hour computable phenotypes are derived using 25 available bedside variables including C-reactive protein and ferritin.

RESULTS

Four computable phenotypes (PedSep-A, B, C, and D) are derived. Compared to all other phenotypes, PedSep-A patients (n = 135; 2% mortality) were younger and previously healthy, with the lowest C-reactive protein and ferritin levels, the highest lymphocyte and platelet counts, highest heart rate, and lowest creatinine (p < 0.05); PedSep-B patients (n = 102; 12% mortality) were most likely to be intubated and had the lowest Glasgow Coma Scale Score (p < 0.05); PedSep-C patients (n = 110; mortality 10%) had the highest temperature and Glasgow Coma Scale Score, least pulmonary failure, and lowest lymphocyte counts (p < 0.05); and PedSep-D patients (n = 56, 34% mortality) had the highest creatinine and number of organ failures, including renal, hepatic, and hematologic organ failure, with the lowest platelet counts (p < 0.05). PedSep-D had the highest likelihood of developing thrombocytopenia-associated multiple organ failure (Adj OR 47.51 95% CI [18.83-136.83], p < 0.0001) and macrophage activation syndrome (Adj OR 38.63 95% CI [13.26-137.75], p < 0.0001).

CONCLUSIONS

Four computable phenotypes are derived, with PedSep-D being optimal for enrollment in early personalized anti-inflammatory trials targeting thrombocytopenia-associated multiple organ failure and macrophage activation syndrome in pediatric sepsis. A computer tool for identification of individual patient membership ( www.pedsepsis.pitt.edu ) is provided. Reproducibility will be assessed at completion of two ongoing pediatric sepsis studies.

Biomarkers associated with mortality in pediatric patients with cardiac arrest and acute respiratory distress syndrome

AIMS

To identify plasma biomarkers associated with cardiac arrest in a cohort of children with acute respiratory distress syndrome (ARDS), and to assess the association of these biomarkers with mortality in children with cardiac arrest and ARDS (ARDS + CA).

METHODS

This was a secondary analysis of a single-center prospective cohort study of children with ARDS from 2014-2019 with 17 biomarkers measured. Clinical characteristics and biomarkers were compared between subjects with ARDS + CA and ARDS with univariate analysis. In a sub-cohort of ARDS + CA subjects, the association between biomarker levels and mortality was tested using univariate and bivariate logistic regression.

RESULTS

Biomarkers were measured in 333 subjects: 301 with ARDS (median age 5.3 years, 55.5% male) and 32 ARDS + CA (median age 8 years, 53.1% male). More arrests (69%) occurred out-of-hospital with a median CPR duration of 11 (IQR 5.5, 25) minutes. ARDS severity, PRISM III score, vasoactive-ionotropic score and extrapulmonary organ failures were worse in the ARDS + CA versus ARDS group. Eight biomarkers were elevated in the ARDS + CA versus ARDS cohort: sRAGE, nucleosomes, SP-D, CCL22, IL-6, HSP70, IL-8, and MIP-1b. sRAGE, SP-D, and CCL22 remained elevated when the cohorts were matched for illness severity. When controlling for severity of ARDS and cardiac arrest characteristics, sRAGE, IL-6 and granzyme B were associated with mortality in the ARDS + CA group.

CONCLUSION

sRAGE, IL-6 and granzyme B were associated with cardiac arrest mortality when controlling for illness severity. sRAGE was consistently higher in the ARDS + CA cohort compared to ARDS and retained independent association with mortality.

Refining the Pediatric Multiple Organ Dysfunction Syndrome

Since its introduction into the medical literature in the 1970s, the term multiple organ dysfunction syndrome (or some variant) has been applied broadly to any patient with >1 concurrent organ dysfunction. However, the epidemiology, mechanisms, time course, and outcomes among children with multiple organ dysfunction vary substantially. We posit that the term pediatric multiple organ dysfunction syndrome (or MODS) should be reserved for patients with a systemic pathologic state resulting from a common mechanism (or mechanisms) that affects numerous organ systems simultaneously. In contrast, children in whom organ injuries are attributable to distinct mechanisms should be considered to have additive organ system dysfunctions but not the syndrome of MODS. Although such differentiation may not always be possible with current scientific knowledge, we make the case for how attempts to differentiate multiple organ dysfunction from other states of additive organ dysfunctions can help to evolve clinical and research priorities in diagnosis, monitoring, and therapy from largely organ-specific to more holistic strategies.

A specialized multi-disciplinary care program for children with sepsis and multiple organ dysfunction-associated immune dysregulation

The complex physiology and medical requirements of children with sepsis and multiple organ dysfunction syndrome (MODS) challenge traditional care coordination models. While the involvement of multiple clinical subspecialty services is often necessary to support different care processes and individual organ system dysfunctions, it can also delay the diagnostic process, monitoring, and treatment. The logistics of coordinating with many specialty providers for critically ill patients are challenging and time consuming, and often can result in fragmented communication. To address these and other related issues, we developed a new multi-disciplinary consult service focused on streamlining diagnostics, management, and communication for patients with sepsis and MODS-associated immune dysregulation. The service, called the Program in Inflammation, Immunity, and the Microbiome (PrIIMe), is now a hospital-wide clinical consult service at our institution caring for a broad group of patients with immune dysregulation, particularly focusing on patients with sepsis and MODS. In this paper, we summarize the development, structure, and function of the program, as well as the initial impact. This information may be helpful to clinicians and healthcare leaders who are developing multi-disciplinary consult services for children with complex care needs, especially those with sepsis and MODS-associated immune dysregulation. IMPACT: The care of children with sepsis and multiple organ dysfunction-associated immune dysregulation requires rapid and flexible involvement of multiple clinical subspecialists that is difficult to achieve without fragmented care and delayed decision making. In this narrative review we describe the development, structure, and function of a multi-disciplinary consult service at a children's hospital dedicated to helping coordinate management and provide continuity of care for patients with sepsis and multiple organ dysfunction-associated immune dysregulation. This information may be helpful to clinicians and healthcare leaders who are developing multi-disciplinary consult services for children with complex care needs, especially those with sepsis and MODS-associated immune dysregulation.

Pediatric Organ Dysfunction Information Update Mandate (PODIUM) Contemporary Organ Dysfunction Criteria: Executive Summary

Prior criteria for organ dysfunction in critically ill children were based mainly on expert opinion. We convened the Pediatric Organ Dysfunction Information Update Mandate (PODIUM) expert panel to summarize data characterizing single and multiple organ dysfunction and to derive contemporary criteria for pediatric organ dysfunction. The panel was composed of 88 members representing 47 institutions and 7 countries. We conducted systematic reviews of the literature to derive evidence-based criteria for single organ dysfunction for neurologic, cardiovascular, respiratory, gastrointestinal, acute liver, renal, hematologic, coagulation, endocrine, endothelial, and immune system dysfunction. We searched PubMed and Embase from January 1992 to January 2020. Study identification was accomplished using a combination of medical subject headings terms and keywords related to concepts of pediatric organ dysfunction. Electronic searches were performed by medical librarians. Studies were eligible for inclusion if the authors reported original data collected in critically ill children; evaluated performance characteristics of scoring tools or clinical assessments for organ dysfunction; and assessed a patient-centered, clinically meaningful outcome. Data were abstracted from each included study into an electronic data extraction form. Risk of bias was assessed using the Quality in Prognosis Studies tool. Consensus was achieved for a final set of 43 criteria for pediatric organ dysfunction through iterative voting and discussion. Although the PODIUM criteria for organ dysfunction were limited by available evidence and will require validation, they provide a contemporary foundation for researchers to identify and study single and multiple organ dysfunction in critically ill children.

IFN-γ signature in the plasma proteome distinguishes pediatric hemophagocytic lymphohistiocytosis from sepsis and SIRS

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome characterized by pathologic immune activation in which prompt recognition and initiation of immune suppression is essential for survival. Children with HLH have many overlapping clinical features with critically ill children with sepsis and systemic inflammatory response syndrome (SIRS) in whom alternative therapies are indicated. To determine whether plasma biomarkers could differentiate HLH from other inflammatory conditions and to better define a core inflammatory signature of HLH, concentrations of inflammatory plasma proteins were compared in 40 patients with HLH to 47 pediatric patients with severe sepsis or SIRS. Fifteen of 135 analytes were significantly different in HLH plasma compared with SIRS/sepsis, including increased interferon-γ (IFN-γ)-regulated chemokines CXCL9, CXCL10, and CXCL11. Furthermore, a 2-analyte plasma protein classifier including CXCL9 and interleukin-6 was able to differentiate HLH from SIRS/sepsis. Gene expression in CD8+ T cells and activated monocytes from blood were also enriched for IFN-γ pathway signatures in peripheral blood cells from patients with HLH compared with SIRS/sepsis. This study identifies differential expression of inflammatory proteins as a diagnostic strategy to identify critically ill children with HLH, and comprehensive unbiased analysis of inflammatory plasma proteins and global gene expression demonstrates that IFN-γ signaling is uniquely elevated in HLH. In addition to demonstrating the ability of diagnostic criteria for HLH and sepsis or SIRS to identify groups with distinct inflammatory patterns, results from this study support the potential for prospective evaluation of inflammatory biomarkers to aid in diagnosis of and optimizing therapeutic strategies for children with distinctive hyperinflammatory syndromes.

Effect of enteral immunomodulatory nutrition formula on mortality and critical care parameters in critically ill patients: A systematic review with meta-analysis

BACKGROUND

Enteral immunomodulatory nutrition is recommended as an adjuvant therapy for patients in intensive care units (ICU), but its effectiveness is incompletely understood.

AIM

The aim of this review was to examine the effect of a commonly used immunomodulatory formula-omega-3 fatty acids, γ-linolenic acid, and antioxidants-on clinical outcomes and mortality risk in critically ill patients.

DESIGN

Systematic review and meta-analysis of randomized controlled trials (RCTs).

METHOD

PubMed, Scopus, and Institute for Scientific Information (ISI) Web of Knowledge databases were searched until 18 February 2021. RCTs that used the immunomodulatory formula in the ICU were included.

RESULTS

Ten RCTs (1166 participants) were included in the meta-analysis. The immunomodulatory formula reduced the duration of ICU stay weighted mean difference [(WMD): -2.97 days; 95%CI: -5.59, -0.35)], mechanical ventilation (WMD = -2.20 days, 95%CI: -4.29, -0.10), sequential organ failure assessment and multiple organ dysfunction scores (Hedge's g: -0.42 U/L; 95% CI: -0.74, -0.11), decreased 8-day overall mortality risk (RR = 0.74, 95% CI: 0.58, 0.91), and extended the ICU-free days (WMD: 4.06 days, 95% CI: 0.02, 8.09). The improvement in respiratory function and reduction in mortality risk was more in patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Furthermore, the reduction in mechanical ventilation and mortality risk was more evident in older (>60 years) vs young adults.

CONCLUSION AND RELEVANCE TO CLINICAL PRACTICE

Taken together, the immunomodulatory formula may enhance clinical practice for critical care nurses, such that the prevalence and/or susceptibility to secondary conditions commonly encountered in the ICU (ie, ALI and ARDS) could be attenuated, ultimately allowing critical care nurses to focus their care on the primary reason for which a patient is in the ICU. The study protocol was registered in PROSPERO.

Morbidity and Mortality in Critically Ill Children. I. Pathophysiologies and Potential Therapeutic Solutions

OBJECTIVES

Developing effective therapies to reduce morbidity and mortality requires knowing the responsible pathophysiologies and the therapeutic advances that are likely to be impactful. Our objective was to determine at the individual patient level the important pathophysiological processes and needed therapeutic additions and advances that could prevent or ameliorate morbidities and mortalities.

DESIGN

Structured chart review by pediatric intensivists of PICU children discharged with significant new morbidity or mortality to determine the pathophysiologies responsible for poor outcomes and needed therapeutic advances.

SETTING

Multicenter study (eight sites) from the Collaborative Pediatric Critical Care Research Network of general and cardiac PICUs.

PATIENTS

First PICU admission of patients from December 2011 to April 2013.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Two-hundred ninety-two patients were randomly selected from 681 patients discharged with significant new morbidity or mortality. The median age was 2.4 years, 233 (79.8%) were in medical/surgical ICUs, 59 (20.2%) were in cardiac ICUs. Sixty-five (22.3%) were surgical admissions. The outcomes included 117 deaths and 175 significant new morbidities. The most common pathophysiologies contributing to the poor outcomes were impaired substrate delivery (n = 158, 54.1%) and inflammation (n = 104, 35.6%). There were no strong correlations between the pathophysiologies and no remarkable clusters among them. The most common therapeutic needs involved new drugs (n = 149, 51.0%), cell regeneration (n = 115, 39.4%), and immune and inflammatory modulation (n = 79, 27.1%). As with the pathophysiologies, there was a lack of strong correlations or meaningful clusters in the suggested therapeutic needs.

CONCLUSIONS

There was no single dominant pathophysiology or cluster of pathophysiologies responsible for poor pediatric critical care outcomes. Therapeutic needs often involved therapies that are not close to implementation such as cell regeneration, improved organ transplant, improved extracorporeal support and artificial organs, and improved drugs.

Metabolism and energy prescription in critically III children

Optimal nutrition therapy can positively influence clinical outcomes in critically ill children. Accurate assessment of nutritional status, metabolic state, macronutrient requirements and substrate utilization allows accurate prescription of nutrition in this population. In response to stress and injury, the body undergoes adaptive physiologic changes leading to dysregulation of the inflammatory response and hyperactivation of the inflammatory cascade. This results in a global catabolic state with modification in oxygen consumption and macronutrient metabolism. A comprehensive understanding of the metabolic response is essential when prescribing nutritional interventions aimed to offset the burden of this adaptive stress response in the critically ill. In this narrative review we aim to provide a comprehensive review of the physiologic basis, recent literature and some emerging concepts related to energy expenditure and the practical aspects of energy delivery in the critically ill child. Based on the unique metabolic characteristics of the critically ill child, we aim to provide a pragmatic approach to providing nutrition therapy.

Multiorgan dysfunction syndrome in sepsis: Is macrophage activation syndrome secondary to infection?

OBJECTIVE

To assess macrophage activation syndrome (MAS) in septic shock leading to multiorgan dysfunction syndrome (MODS).

METHODS

A prospective observational study was conducted at a tertiary care hospital to evaluate the MAS criteria in different stages of sepsis. Children aged 6 months to 12 years in different stages of septic shock were recruited. The Paediatric Rheumatology International Trials Organisation Collaborative Initiative (PRINTO) criteria of MAS were applied initially at the stage of septic shock and subsequently at the stage of MODS (MODS cohort) or following recovery from septic shock without going through MODS (non-MODS cohort).

RESULTS

A total of 127 subjects were studied, with 53 comprising the MODS cohort and the rest 74 the non-MODS cohort. At the initial assessment, a comparable proportion of subjects in the MODS and non-MODS groups satisfied the MAS criteria (20.75% and 25.68%, respectively; p=0.529). However, by the time of progression to MODS, 81.13% of the subjects satisfied the MAS criteria in the MODS group, whereas only 16.18% subjects in the non-MODS group continued to satisfy the MAS criteria (p<0.001). Thus, there was a definite increase in the proportion of subjects showing MAS by the time they progressed to multiorgan dysfunction (p<0.001). In contrast, the proportion declined significantly (25.68% to 16.18%; p=0.008) in the subjects who had recovered.

CONCLUSION

The findings bear out the hypothesis that MODS in sepsis is a reflection of MAS secondary to sepsis. However, studies in larger cohorts are needed to validate these findings and explore the therapeutic implications.

Risk Factors for Mortality in Refractory Pediatric Septic Shock Supported with Extracorporeal Life Support

Risk factors for mortality in children with refractory pediatric septic shock who are supported with extracorporeal life support (ECLS) are largely unknown. Therefore, we performed univariable and multivariable analyses to determine risk factors for mortality among children (<19 years) who underwent an ECLS run between January 2012 and September 2014 at eight tertiary pediatric hospitals, and who had septic shock based on 2005 International Consensus Criteria. Of the 514 children treated with ECLS during the study period, 70 were identified with septic shock. The mortality rate was similar between those with (54.3%) and without septic shock (43.7%). Among those with septic shock, significant risk factors for mortality included cardiac failure or extracorporeal cardiopulmonary resuscitation (ECPR) as indication for ECLS cannulation compared with respiratory failure (P = 0.003), having a new neurologic event following cannulation (P = 0.032), acquiring a new infection following cannulation (P = 0.005), inability to normalize pH in the 48 hours following ECLS cannulation (P = 0.010), and requiring higher daily volume of platelet transfusions (P = 0.005). These findings can be used to help guide clinical decision making for children with septic shock that is refractory to medical management.

Acute and chronic neuroinflammation is triggered by diabetic ketoacidosis in a rat model

INTRODUCTION

Cognitive decline is common in patients with type 1 diabetes and has been attributed to the effects of chronic hyperglycemia and severe hypoglycemia. Diabetic ketoacidosis (DKA) has only recently been suspected to be involved in causing cognitive decline. We hypothesized that DKA triggers both acute and chronic neuroinflammation, contributing to brain injury.

RESEARCH METHODS AND DESIGN

We measured concentrations of cytokines, chemokines and matrix metalloproteinases (MMP) in serum and brain tissue lysates in juvenile rats during and after DKA (during acute DKA, 24 hours and 7 days after DKA), and compared these to healthy controls and hyperglycemic controls. We also measured cytokine, chemokine and MMP concentrations in serum and brain tissue of adult rats (70 days) that had experienced DKA as juveniles and compared these measurements to those of adult diabetic rats without exposure to DKA.

RESULTS

During acute DKA in the juvenile rats, serum concentrations of CCL3, tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and MMP-9 were significantly increased. Serum concentrations of IL-2 and IL-17A increased 7 days after DKA recovery. In brain tissue lysates, concentrations of CCL3, CCL5, interferon (IFN)-γ and MMP-9 were significantly elevated during acute DKA. In adult rats that had DKA as juveniles (28 days previously), serum concentrations of IL-1ß and brain concentrations of IL-10 and IL-12p70 were elevated in comparison to diabetic rats without prior DKA. Composite scores for highly correlated cytokines and chemokines (mean z-scores for IL-10, IL-1ß, TNF-α, IL-17A, IFN-γ, CXCL-1 and CCL5) were also significantly elevated in adult rats with prior DKA.

CONCLUSIONS

These data confirm that DKA causes acute systemic inflammation and neuroinflammation in a rat model. Importantly, the neuroinflammatory response triggered by DKA is long-lasting, suggesting the possibility that DKA-induced chronic neuroinflammation could contribute to long-term cognitive decline in individuals with diabetes.

Rise in Angiopoietin-2 Following Neonatal Cardiac Surgery Is Associated With Adverse Clinical Outcomes

OBJECTIVES

Neonatal cardiac surgery for congenital cardiac defects is associated with significant morbidity and mortality, and there is a need for early identification of patients at highest risk of adverse outcomes. Because vascular endothelial injury mediates damage across organ systems, we measured serum biomarkers of endothelial injury in neonates following cardiopulmonary bypass and examined their associations with short-term outcomes.

DESIGN

Prospective cohort study.

SETTING

Pediatric cardiac ICU.

PATIENTS

Thirty neonates less than 2 weeks old undergoing repair of congenital cardiac defects with cardiopulmonary bypass.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Biomarkers of endothelial integrity, angiopoietin-1 and angiopoietin-2, were measured preoperatively and at 24 hours postoperatively. A composite adverse outcome was defined as any of the following: stroke, need for renal replacement therapy, extracorporeal membrane oxygenation support, cardiac arrest, or death. Associations of biomarkers with adverse outcomes were examined using Wilcoxon rank-sum test. There was an increase in angiopoietin-2 from preoperatively to 24 hours postoperatively (p < 0.0001) and a decrease in angiopoietin-1 from preoperatively to 24 hours postoperatively (p < 0.0001). Patients with greater rise in angiopoietin-2 from preoperatively to 24 hours postoperatively had greater risk of composite adverse outcome (p = 0.04). They had a trend toward higher Vasoactive-Inotropic Score (p = 0.06) and a higher prevalence of low cardiac output syndrome (p = 0.06). Twenty-four hour postoperative angiopoietin-2 level was associated with the composite adverse outcome (p = 0.03). The rise in angiopoietin-2 level from preoperatively to 24 hours postoperatively directly correlated with cardiopulmonary bypass duration (r = 0.47; p = 0.01).

CONCLUSIONS

In neonatal cardiac surgery, longer duration of cardiopulmonary bypass is directly associated with greater endothelial injury as measured by increased serum levels of angiopoietin-2. Angiopoietin-2 levels 24 hours postoperatively were significantly associated with a composite adverse outcome. Postoperative angiopoietin-2 level may serve as an early indicator of patients in need of closer monitoring and protective intervention. Further research into endothelial protective strategies is warranted.

Associations of Plasma Angiopoietins-1 and -2 and Angiopoietin-2/-1 Ratios With Measures of Organ Injury and Clinical Outcomes in Children With Sepsis: A Preliminary Report

OBJECTIVES

Results from preclinical and adult sepsis studies suggest that the balance of circulating angiopoietin-1 and -2 levels, represented as angiopoietin-2/-1 ratios, plays a pivotal role in mediating vascular dysfunction and organ injury during sepsis. However, the relationship of plasma angiopoietins with organ injury and clinical outcomes in children with sepsis remains unknown. We sought to determine whether plasma angiopoietin-1 and -2 levels and angiopoietin-2/-1 ratios in the acute phase of sepsis correlated with measures of organ injury and clinical outcomes in children with sepsis.

DESIGN

Prospective observational cohort study.

SETTING

PICU within a tertiary freestanding children's hospital.

PATIENTS

Children 18 years old or less and greater than 3 kg admitted to the PICU for sepsis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Plasma angiopoietin-1 and -2 levels were measured in 38 children with sepsis 0-6, 24, 48, and 72 hours following PICU admission. Children with elevated pediatric Sequential Organ Failure Assessment scores on the third day after PICU admission demonstrated significantly higher 24-72-hour angiopoietin-2/-1 ratios predominantly as a function of higher angiopoietin-2 levels. In children with sepsis-induced organ dysfunction, angiopoietin-2/-1 ratios correlated with oxygenation indices and serum levels of creatinine and bilirubin. Forty-eight- and 72-hour angiopoietin-2/-1 ratios correlated with PICU length of stay (Spearman rho = 0.485, p = 0.004 and rho = 0.440, p = 0.015, respectively).

CONCLUSIONS

In the acute phase of sepsis in children, plasma angiopoietin-2/-1 ratios rise significantly above control levels and correlate with measures of organ injury and worse clinical outcomes after 24 hours. Our findings suggest that angiopoietin dysregulation begins early in sepsis and, if sustained, may promote greater organ injury that can lead to worse clinical outcomes.

Derivation and Validation of Novel Phenotypes of Multiple Organ Dysfunction Syndrome in Critically Ill Children

IMPORTANCE

Multiple organ dysfunction syndrome (MODS) is a dynamic and heterogeneous process associated with high morbidity and mortality in critically ill children.

OBJECTIVE

To determine whether data-driven phenotypes of MODS based on the trajectories of 6 organ dysfunctions have prognostic and therapeutic relevance in critically ill children.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included 20 827 pediatric intensive care encounters among 14 285 children admitted to 2 large academic pediatric intensive care units (PICUs) between January 2010 and August 2016. Patients were excluded if they were older than 21 years or had undergone cardiac surgery. The 6 subscores of the pediatric Sequential Organ Failure Assessment (pSOFA) score were calculated for the first 3 days, including the subscores for respiratory, cardiovascular, coagulation, hepatic, neurologic, and renal dysfunctions. MODS was defined as a pSOFA subscore of at least 2 in at least 2 organs. Encounters were split in a 80:20 ratio for derivation and validation, respectively. The trajectories of the 6 subscores were used to derive a set of data-driven phenotypes of MODS using subgraph-augmented nonnegative matrix factorization in the derivation set. Data analysis was conducted from March to October 2019.

EXPOSURES

The primary exposure was phenotype membership. In the subset of patients with vasoactive-dependent shock, the interaction between hydrocortisone and phenotype membership and its association with outcomes were examined in a matched cohort.

MAIN OUTCOMES AND MEASURES

The primary outcome was in-hospital mortality. Secondary outcomes included persistent MODS on day 7, and vasoactive-free, ventilator-free, and hospital-free days. Regression analysis was used to adjust for age, severity of illness, immunocompromised status, and study site.

RESULTS

There were 14 285 patients with 20 827 encounters (median [interquartile range] age 5.2 years [1.5-12.7] years; 11 409 [54.8%; 95% CI, 54.1%-55.5%] male patients). Of these, 5297 encounters (25.4%; 95% CI, 24.8%-26.0%) were with patients who had MODS, of which 5054 (95.4%) met the subgraph count threshold and were included in the analysis. Subgraph augmented nonnegative matrix factorization uncovered 4 data-driven phenotypes of MODS, characterized by a combination of neurologic, respiratory, coagulation, and cardiovascular dysfunction, as follows: phenotype 1, severe, persistent encephalopathy (1019 patients [19.2%]); phenotype 2, moderate, resolving hypoxemia (1828 patients [34.5%]); phenotype 3, severe, persistent hypoxemia and shock (1012 patients [19.1%]); and phenotype 4, moderate, persistent thrombocytopenia and shock (1195 patients [22.6%]). These phenotypes were reproducible in a validation set of encounters, had distinct clinical characteristics, and were independently associated with outcomes. For example, using phenotype 2 as reference, the adjusted hazard ratios (aHRs) for death by 28 days were as follows: phenotype 1, aHR of 3.0 (IQR, 2.1-4.3); phenotype 3, aHR of 2.8 (IQR, 2.0-4.1); and phenotype 4, aHR of 1.8 (IQR, 1.2-2.6). Interaction analysis in a matched cohort of patients with vasoactive-dependent shock revealed that hydrocortisone had differential treatment association with vasoactive-free days across phenotypes. For example, patients in phenotype 3 who received hydrocortisone had more vasoactive-free days than those who did not (23 days vs 18 days; P for interaction < .001), whereas patients in other phenotypes who received hydrocortisone either had no difference or had less vasoactive-free days.

CONCLUSIONS AND RELEVANCE

In this study, data-driven phenotyping in critically ill children with MODS uncovered 4 distinct and reproducible phenotypes with prognostic relevance and possible therapeutic relevance. Further validation and characterization of these phenotypes is warranted.

Venous Thromboembolism in Children: From Diagnosis to Management

Venous thromboembolism (VTE) in children is a rare occurrence, although in recent decades we have seen an increase due to several factors, such as the rise in survival of subjects with chronic conditions, the use of catheters, and the increased sensitivity of diagnostic tools. Besides inherited thrombophilia, acquired conditions such as cardiovascular diseases, infections, chronic disorders, obesity and malignancy are also common risk factors for paediatric VTE. The treatment of paediatric VTE consists of the use of heparins and/or vitamin K antagonists to prevent dissemination, embolization, and secondary VTE. Randomized clinical trials of direct oral anticoagulants in paediatric VTE are ongoing, with the aim to improve the compliance and the care of patients. We reviewed the physiological and pathological mechanisms underlying paediatric thrombosis and updated the current diagnosis and treatment options.

Scrub typhus with multi-organ dysfunction syndrome and immune thrombocytopenia: a case report and review of the literature

BACKGROUND

Scrub typhus is an acute infectious zoonotic disease caused by Orientia tsutsugamushi. Multi-organ dysfunction secondary to scrub typhus is hard to diagnose and has a high mortality rate. Only one case of scrub typhus with multi-organ dysfunction syndrome and immune thrombocytopenia has been reported thus far. In this study, we report a second case of scrub typhus with multi-organ dysfunction syndrome and immune thrombocytopenia, and we summarize its diagnosis and treatment.

CASE PRESENTATION

A 43-year-old Han Chinese woman, a sanitation worker, was admitted to our hospital after 7 days of a skin infection and 5 days of a sore throat with fever and dizziness. A physical examination revealed the presence of an eschar on the right side of her neck. She had a history of insect bites during her sanitation work. A diagnostic evaluation identified scrub typhus as the primary illness, which was associated with multi-organ dysfunction syndrome and immune thrombocytopenia. She recovered completely after 15 days of treatment and extensive symptomatic supportive care.

CONCLUSION

We report a second case of tsutsugamushi disease with multi-organ dysfunction syndrome and immune thrombocytopenia, which resolved after treatment and extensive care.

A Multicenter Network Assessment of Three Inflammation Phenotypes in Pediatric Sepsis-Induced Multiple Organ Failure

OBJECTIVES

Ongoing adult sepsis clinical trials are assessing therapies that target three inflammation phenotypes including 1) immunoparalysis associated, 2) thrombotic microangiopathy driven thrombocytopenia associated, and 3) sequential liver failure associated multiple organ failure. These three phenotypes have not been assessed in the pediatric multicenter setting. We tested the hypothesis that these phenotypes are associated with increased macrophage activation syndrome and mortality in pediatric sepsis.

DESIGN

Prospective severe sepsis cohort study comparing children with multiple organ failure and any of these phenotypes to children with multiple organ failure without these phenotypes and children with single organ failure.

SETTING

Nine PICUs in the Eunice Kennedy Shriver National Institutes of Child Health and Human Development Collaborative Pediatric Critical Care Research Network.

PATIENTS

Children with severe sepsis and indwelling arterial or central venous catheters.

INTERVENTIONS

Clinical data collection and twice weekly blood sampling until PICU day 28 or discharge.

MEASUREMENTS AND MAIN RESULTS

Of 401 severe sepsis cases enrolled, 112 (28%) developed single organ failure (0% macrophage activation syndrome 0/112; < 1% mortality 1/112), whereas 289 (72%) developed multiple organ failure (9% macrophage activation syndrome 24/289; 15% mortality 43/289). Overall mortality was higher in children with multiple organ and the phenotypes (24/101 vs 20/300; relative risk, 3.56; 95% CI, 2.06-6.17). Compared to the 188 multiple organ failure patients without these inflammation phenotypes, the 101 multiple organ failure patients with these phenotypes had both increased macrophage activation syndrome (19% vs 3%; relative risk, 7.07; 95% CI, 2.72-18.38) and mortality (24% vs 10%; relative risk, 2.35; 95% CI, 1.35-4.08).

CONCLUSIONS

These three inflammation phenotypes were associated with increased macrophage activation syndrome and mortality in pediatric sepsis-induced multiple organ failure. This study provides an impetus and essential baseline data for planning multicenter clinical trials targeting these inflammation phenotypes in children.

TSLP Exacerbates Septic Inflammation via Murine Double Minute 2 (MDM2) Signaling Pathway

Thymic stromal lymphopoietin (TSLP) is crucial for Th2-mediated inflammation. Sepsis is a serious systemic inflammatory reaction with organ dysfunction by infection. However, the function of TSLP during sepsis is poorly understood. Thus, we investigated a role and regulatory mechanism of TSLP during sepsis. Sepsis was induced by lipopolysaccharides (LPS) or Escherichia coli DH5α injection in mice. TSLP levels were measured in human subjects, mice, and macrophages. TSLP deficiency or murine double minute 2 (MDM2) deficiency was induced using siRNA or an MDM2 inhibitor, nutlin-3a. We found that TSLP levels were elevated in serum of patients and mice with sepsis. TSLP deficiency lowered liver damage and inflammatory cytokine levels in mice with sepsis. TSLP was produced by the MDM2/NF-κB signaling pathway in LPS-stimulated macrophages. TSLP downregulation by an MDM2 inhibitor, nutlin-3a, alleviated clinical symptoms and septic inflammatory responses. Pharmacological inhibition of TSLP level by cisplatin reduced the septic inflammatory responses. Altogether, the present results show that TSLP exacerbates septic inflammation via the MDM2 signaling pathway, suggesting that TSLP may be a potential target for the treatment of sepsis.

Targeting Complement Pathways in Polytrauma- and Sepsis-Induced Multiple-Organ Dysfunction

Exposure to traumatic or infectious insults results in a rapid activation of the complement cascade as major fluid defense system of innate immunity. The complement system acts as a master alarm system during the molecular danger response after trauma and significantly contributes to the clearance of DAMPs and PAMPs. However, depending on the origin and extent of the damaged macro- and micro -milieu, the complement system can also be either excessively activated or inhibited. In both cases, this can lead to a maladaptive immune response and subsequent multiple cellular and organ dysfunction. The arsenal of complement-specific drugs offers promising strategies for various critical conditions after trauma, hemorrhagic shock, sepsis, and multiple organ failure. The imbalanced immune response needs to be detected in a rational and real-time manner before the translational therapeutic potential of these drugs can be fully utilized. Overall, the temporal-spatial complement response after tissue trauma and during sepsis remains somewhat enigmatic and demands a clinical triad: reliable tissue damage assessment, complement activation monitoring, and potent complement targeting to highly specific rebalance the fluid phase innate immune response.

Fluid treatment for children with diabetic ketoacidosis: How do the results of the pediatric emergency care applied research network Fluid Therapies Under Investigation in Diabetic Ketoacidosis (FLUID) Trial change our perspective?

The optimal fluid treatment protocol for children with diabetic ketoacidosis (DKA) has long been a subject of controversy. Until recently, there was no high-quality evidence from randomized clinical trials to support an optimal guideline, and recommendations were mainly based on theoretical considerations. As a consequence, fluid treatment protocols for children with DKA vary between institutions (and countries). In June 2018, the results from the Fluid Therapies Under Investigation in DKA Trial conducted in the Pediatric Emergency Care Applied Research Network were published. This large, factorial-designed randomized controlled trial assessed neurological outcomes of 1387 children with DKA who were treated with one of four fluid protocols that varied in infusion rate and sodium content. In this commentary, we review and discuss the results of this new study and the implications for clinical care of DKA in children.

Effects of different periods of gastric ischemia on liver as a remote organ1

PURPOSE

To evaluate the hepatic changes associated with gastric ischemia.

METHODS

Thirty male rabbits were studied, distributed in 3 groups (n=10). Group 1: ligature and section of the gastric vasculature and removal of the liver after three hours; Group 2: ligature and section of the gastric vasculature and removal of the liver after 6 hours; Group 3: ligature and section of the gastric vasculature and removal of the liver after 12 hours. Blood samples were collected immediately before surgery and after the determined time of ischemia in each group to evaluate the hepatic function. After the death of the rabbits, the liver was removed for macro and microscopic study.

RESULTS

An increase in aminotransferases and bilirubin occurred in groups 2 and 3. Total protein and albumin diminished in all of the animals. All of the rabbits from groups 2 and 3 presented hepatocellular necrosis.

CONCLUSION

The devascularization of the stomach for a period of above three hours is associated with hepatic morphological and functional disorders.

Hepatobiliary Dysfunction and Disseminated Intravascular Coagulation Increase Risk of Mortality in Pediatric Hemophagocytic Lymphohistiocytosis

OBJECTIVES

Hemophagocytic lymphohistiocytosis poses significant challenges due to limited tools to guide clinical decisions in a population at high risk of death. We sought to assess whether disseminated intravascular coagulation and hepatobiliary dysfunction, significant comorbidities seen in critical care settings, would identify hemophagocytic lymphohistiocytosis patients with increased risk of mortality.

DESIGN

Retrospective chart review.

SETTING

Single-center PICU.

PATIENTS

All patients admitted to a tertiary care children's hospital diagnosed with hemophagocytic lymphohistiocytosis from 2005 to 2012.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Forty-three patients were diagnosed with hemophagocytic lymphohistiocytosis with median age of 61 months. The 5-year overall survival was 51% (22/43). Univariate analyses revealed ferritin levels greater than 10,000 (ng/mL), international normalized ratio greater than 1.5, or platelet counts less than 100,000/µL at initiation of dexamethasone were individually associated with mortality. Development of disseminated intravascular coagulation, hepatobiliary dysfunction, or both increased the likelihood of death in hemophagocytic lymphohistiocytosis patients (relative risk; 95% CI) (6; 1.4-34; p < 0.05), (4.1; 1.8-10; p < 0.05), and (7.5; 1.8-42; p < 0.05). Of 12 autopsies performed, 75% had at least one active infection, 66% had chronic lymphopenia, 50% had lymphocyte depletion in the spleen, thymus, or bone marrow, 42% had evidence of microvascular thrombosis, and 92% had evidence of hepatocellular injury.

CONCLUSIONS

Hemophagocytic lymphohistiocytosis continues to have high mortality with hemophagocytic lymphohistiocytosis-1994/2004 (dexamethasone/etoposide), the current standard of care for all children with hemophagocytic lymphohistiocytosis. Hemophagocytic lymphohistiocytosis patients who developed disseminated intravascular coagulation, hepatobiliary dysfunction, or both had higher risk of death with mortalities of 60%, 77%, and 77%, respectively. Phenotypic classifications are urgently needed to guide individualized treatment strategies to improve outcomes for children with hemophagocytic lymphohistiocytosis.