Revisiting Post-ICU Admission Fluid Balance Across Pediatric Sepsis Mortality Risk Strata: A Secondary Analysis of a Prospective Observational Cohort Study.

OBJECTIVES: Post-ICU admission cumulative positive fluid balance (PFB) is associated with increased mortality among critically ill patients. We sought to test whether this risk varied across biomarker-based risk strata upon adjusting for illness severity, presence of severe acute kidney injury (acute kidney injury), and use of continuous renal replacement therapy (CRRT) in pediatric septic shock. DESIGN: Ongoing multicenter prospective observational cohort. SETTING: Thirteen PICUs in the United States (2003-2023). PATIENTS: Six hundred and eighty-one children with septic shock. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Cumulative percent PFB between days 1 and 7 (days 1-7 %PFB) was determined. Primary outcome of interest was complicated course defined as death or persistence of greater than or equal to two organ dysfunctions by day 7. Pediatric Sepsis Biomarker Risk Model (PERSEVERE)-II biomarkers were used to assign mortality probability and categorize patients into high mortality (n = 91), intermediate mortality (n = 134), and low mortality (n = 456) risk strata. Cox proportional hazard regression models with adjustment for PERSEVERE-II mortality probability, presence of sepsis-associated acute kidney injury on day 3, and use of CRRT, demonstrated that time-dependent variable days 1-7%PFB was independently associated with an increased hazard of complicated course. Risk-stratified analyses revealed that each 10% increase in days 1-7 %PFB was associated with increased hazard of complicated course only among patients with high mortality risk strata (adjusted hazard ratio 1.24 (95% CI, 1.08-1.43), p = 0.003). However, this association was not causally mediated by PERSEVERE-II biomarkers. CONCLUSIONS: Our data demonstrate the influence of cumulative %PFB on the risk of complicated course in pediatric septic shock. Contrary to our previous report, this risk was largely driven by patients categorized as having a high mortality risk based on PERSEVERE-II biomarkers. Incorporation of such prognostic enrichment tools in randomized trials of restrictive fluid management or early initiation of de-escalation strategies may inform targeted application of such interventions among at-risk patients.

Derivation, validation, and transcriptomic assessment of pediatric septic shock phenotypes identified through latent profile analyses: Results from a prospective multi-center observational cohort.

Background: Sepsis poses a grave threat, especially among children, but treatments are limited due to clinical and biological heterogeneity among patients. Thus, there is an urgent need for precise subclassification of patients to guide therapeutic interventions. Methods: We used clinical, laboratory, and biomarker data from a prospective multi-center pediatric septic shock cohort to derive phenotypes using latent profile analyses. Thereafter, we trained a support vector machine model to assign phenotypes in a hold-out validation set. We tested interactions between phenotypes and common sepsis therapies on clinical outcomes and conducted transcriptomic analyses to better understand the phenotype-specific biology. Finally, we compared whether newly identified phenotypes overlapped with established gene-expression endotypes and tested the utility of an integrated subclassification scheme. Findings: Among 1,071 patients included, we identified two phenotypes which we named 'inflamed' (19.5%) and an 'uninflamed' phenotype (80.5%). The 'inflamed' phenotype had an over 4-fold risk of 28-day mortality relative to those 'uninflamed'. Transcriptomic analysis revealed overexpression of genes implicated in the innate immune response and suggested an overabundance of developing neutrophils, pro-T/NK cells, and NK cells among those 'inflamed'. There was no significant overlap between endotypes and phenotypes. However, an integrated subclassification scheme demonstrated varying survival probabilities when comparing endophenotypes. Interpretation: Our research underscores the reproducibility of latent profile analyses to identify clinical and biologically informative pediatric septic shock phenotypes with high prognostic relevance. Pending validation, an integrated subclassification scheme, reflective of the different facets of the host response, holds promise to inform targeted intervention among those critically ill.

Prognostic and predictive value of endothelial dysfunction biomarkers in sepsis-associated acute kidney injury: risk-stratified analysis from a prospective observational cohort of pediatric septic shock.

BACKGROUND: Sepsis-associated acute kidney injury (SA-AKI) is associated with high morbidity, with no current therapies available beyond continuous renal replacement therapy (CRRT). Systemic inflammation and endothelial dysfunction are key drivers of SA-AKI. We sought to measure differences between endothelial dysfunction markers among children with and without SA-AKI, test whether this association varied across inflammatory biomarker-based risk strata, and develop prediction models to identify those at highest risk of SA-AKI. METHODS: Secondary analyses of prospective observational cohort of pediatric septic shock. Primary outcome of interest was the presence of ≥ Stage II KDIGO SA-AKI on day 3 based on serum creatinine (D3 SA-AKI SCr). Biomarkers including those prospectively validated to predict pediatric sepsis mortality (PERSEVERE-II) were measured in Day 1 (D1) serum. Multivariable regression was used to test the independent association between endothelial markers and D3 SA-AKI SCr. We conducted risk-stratified analyses and developed prediction models using Classification and Regression Tree (CART), to estimate risk of D3 SA-AKI among prespecified subgroups based on PERSEVERE-II risk. RESULTS: A total of 414 patients were included in the derivation cohort. Patients with D3 SA-AKI SCr had worse clinical outcomes including 28-day mortality and need for CRRT. Serum soluble thrombomodulin (sTM), Angiopoietin-2 (Angpt-2), and Tie-2 were independently associated with D3 SA-AKI SCr. Further, Tie-2 and Angpt-2/Tie-2 ratios were influenced by the interaction between D3 SA-AKI SCr and risk strata. Logistic regression demonstrated models predictive of D3 SA-AKI risk performed optimally among patients with high- or intermediate-PERSEVERE-II risk strata. A 6 terminal node CART model restricted to this subgroup of patients had an area under the receiver operating characteristic curve (AUROC) 0.90 and 0.77 upon tenfold cross-validation in the derivation cohort to distinguish those with and without D3 SA-AKI SCr and high specificity. The newly derived model performed modestly in a unique set of patients (n = 224), 84 of whom were deemed high- or intermediate-PERSEVERE-II risk, to distinguish those patients with high versus low risk of D3 SA-AKI SCr. CONCLUSIONS: Endothelial dysfunction biomarkers are independently associated with risk of severe SA-AKI. Pending validation, incorporation of endothelial biomarkers may facilitate prognostic and predictive enrichment for selection of therapeutics in future clinical trials among critically ill children.

SERUM SOLUBLE ENDOGLIN IN PEDIATRIC SEPTIC SHOCK-ASSOCIATED MULTIPLE ORGAN DYSFUNCTION SYNDROME.

ABSTRACT: Background: Endothelial activation is a key driver of multiple organ dysfunction syndrome (MODS). Soluble endoglin (sENG) is expressed by mature and progenitor endothelial cells and thought to have angiogenic properties. We sought to determine the association between sENG and pediatric sepsis-associated MODS. Methods: Prospective observational study of pediatric septic shock. Primary outcome of interest was complicated course-a composite of death by (or) MODS on day 7 of illness. Secondary outcomes included individual organ dysfunctions. Endothelial biomarkers including sENG were measured using multiplex Luminex assays among patients with existing data on the Pediatric Sepsis Biomarker Risk Model (PERSEVERE-II) data. Multivariable regression was used to test the independent association between sENG and clinical outcomes. Serum sENG concentrations across PERSEVERE-II mortality risk strata and correlations with established markers of endothelial dysfunction were determined. Results: Three hundred six critically ill children with septic shock were included. Serum sENG concentrations were higher among those with primary and secondary outcomes of interest, with the exception of acute neurological dysfunction. Soluble endoglin was independently associated with increased odds of complicated course (adjusted odds ratio, 1.53; 95% confidence interval, 1.02-2.27; P = 0.038) and acute renal dysfunction (adjusted odds ratio, 1.84; 95% confidence interval, 1.18-2.876; P = 0.006). Soluble endoglin demonstrated graded responses across PERSEVERE-II risk strata and was positively correlated with endothelial biomarkers, except angiopoietin-1. Conclusions: Serum sENG is independently associated with complicated course and acute renal dysfunction in pediatric septic shock. Future studies are required to validate our observational data, and mechanistic studies are necessary to elucidate whether endoglin plays an organ-specific role in the development or resolution of acute renal dysfunction in sepsis.

Revisiting post-ICU admission fluid balance across pediatric sepsis mortality risk strata: A secondary analyses from a prospective observational cohort study.

Introduction: Post-ICU admission cumulative positive fluid balance (PFB) is associated with increased mortality among critically ill patients. We sought to test whether this risk varied across biomarker-based risk strata upon adjusting for illness severity, presence of severe acute kidney injury (AKI), and use of renal replacement therapy (CRRT) in pediatric septic shock. Design: Ongoing multi-center prospective observational cohort. Setting: Thirteen pediatric ICUs in the United States (2003-2023). Patients: Six hundred and eighty-one children with septic shock. Interventions: None. Measurements and Main Results: Cumulative percent positive fluid balance between day 1-7 (Day 1-7%PFB) was determined. Primary outcome of interest was complicated course defined as death or persistence of ≥ 2 organ dysfunctions by day 7. PERSEVERE-II biomarkers were used to assign mortality probability and categorize patients into high (n = 91), intermediate (n = 134), and low (n = 456) mortality risk strata. Cox proportional hazard regression models with adjustment for PERSEVERE-II mortality probability, presence of sepsis associated acute kidney injury (SA-AKI) on Day 3, and any use of CRRT, demonstrated that time-dependent variable Day 1-7%PFB was independently associated with increased hazard of complicated course in the cohort. Risk stratified analyses revealed that each 10% increase in Day 1-7%PFB was independently associated with increased hazard of complicated course among patients with high mortality risk strata (adj HR of 1.24 (95%CI: 1.08-1.42), p = 0.002), but not among those categorized as intermediate- or low- mortality risk. Conclusions: Our data demonstrate the independent influence of cumulative %PFB on the risk of complicated course. Contrary to our previous report, this risk was largely driven by patients categorized as having a high-mortality risk based on PERSEVERE-II biomarkers. Further research is necessary to determine whether this subset of patients may benefit from targeted deployment of restrictive fluid management or early initiation of de-escalation therapies upon resolution of shock.

Detrimental effects of PCSK9 loss-of-function in the pediatric host response to sepsis are mediated through independent influence on Angiopoietin-1.

BACKGROUND: Sepsis is associated with significant mortality. Yet, there are no efficacious therapies beyond antibiotics. PCSK9 loss-of-function (LOF) and inhibition, through enhanced low-density lipoprotein receptor (LDLR) mediated endotoxin clearance, holds promise as a potential therapeutic approach among adults. In contrast, we have previously demonstrated higher mortality in the juvenile host. Given the potential pleiotropic effects of PCSK9 on the endothelium, beyond canonical effects on serum lipoproteins, both of which may influence sepsis outcomes, we sought to test the influence of PCSK9 LOF genotype on endothelial dysfunction. METHODS: Secondary analyses of a prospective observational cohort of pediatric septic shock. Genetic variants of PCSK9 and LDLR genes, serum PCSK9, and lipoprotein concentrations were determined previously. Endothelial dysfunction markers were measured in day 1 serum. We conducted multivariable linear regression to test the influence of PCSK9 LOF genotype on endothelial markers, adjusted for age, complicated course, and low- and high-density lipoproteins (LDL and HDL). Causal mediation analyses to test impact of select endothelial markers on the association between PCSK9 LOF genotype and mortality. Juvenile Pcsk9 null and wildtype mice were subject to cecal slurry sepsis and endothelial markers were quantified. RESULTS: A total of 474 patients were included. PCSK9 LOF was associated with several markers of endothelial dysfunction, with strengthening of associations after exclusion of those homozygous for the rs688 LDLR variant that renders it insensitive to PCSK9. Serum PCSK9 was not correlated with endothelial dysfunction. PCSK9 LOF influenced concentrations of Angiopoietin-1 (Angpt-1) upon adjusting for potential confounders including lipoprotein concentrations, with false discovery adjusted p value of 0.042 and 0.013 for models that included LDL and HDL, respectively. Causal mediation analysis demonstrated that the effect of PCSK9 LOF on mortality was mediated by Angpt-1 (p = 0.0008). Murine data corroborated these results with lower Angpt-1 and higher soluble thrombomodulin among knockout mice with sepsis relative to the wildtype. CONCLUSIONS: We present genetic and biomarker association data that suggest a potential direct role of the PCSK9-LDLR pathway on Angpt-1 in the developing host with septic shock and warrant external validation. Further, mechanistic studies on the role of PCSK9-LDLR pathway on vascular homeostasis may lead to the development of pediatric-specific sepsis therapies.

A Targeted Analysis of Serial Cytokine Measures and Nonpulmonary Organ System Failure in Children With Acute Respiratory Failure: Individual Measures and Trajectories Over Time.

OBJECTIVES: There is a need for research exploring the temporal trends of nonpulmonary organ dysfunction (NPOD) and biomarkers in order to identify unique predictive or prognostic phenotypes. We examined the associations between the number and trajectories of NPODs and plasma biomarkers of early and late inflammatory cascade activation, specifically plasma interleukin-1 receptor antagonist (IL-1ra) and interleukin-8 (IL-8), respectively, in the setting of acute respiratory failure (ARF). DESIGN: Secondary analysis of the Randomized Evaluation for Sedation Titration for Respiratory Failure clinical trial and Biomarkers in Acute Lung Injury (BALI) ancillary study. SETTING: Multicenter. PATIENTS: Intubated pediatric patients with ARF. INTERVENTIONS: NPODs were evaluated against plasma IL-1ra and IL-8 levels on individual days (1 to 4 d after intubation) and longitudinally across days. MEASUREMENTS AND MAIN RESULTS: Within the BALI cohort, 432 patients had at least one value for IL-1ra or IL-8 within days 0 through 5. 36.6% had a primary diagnosis of pneumonia, 18.5% had a primary diagnosis of sepsis and 8.1% died. Multivariable logistic regression models showed that increasing levels of both plasma IL-1ra and IL-8 were statistically significantly associated with increasing numbers of NPODs (IL-1ra: days 1-3; IL-8: days 1-4), independent of sepsis diagnosis, severity of oxygenation defect, age, and race/ethnicity. Longitudinal trajectory analysis identified four distinct NPOD trajectories and seven distinct plasma IL-1ra and IL-8 trajectories. Multivariable ordinal logistic regression revealed that specific IL-1ra and IL-8 trajectory groups were associated with greater NPOD trajectory group ( p = 0.004 and p < 0.0001, respectively), independent of severity of oxygenation defect, age, sepsis diagnosis, and race/ethnicity. CONCLUSIONS: Both the inflammatory biomarkers and number of NPODs exhibit distinct trajectories over time with strong associations with one another. These biomarkers and their trajectory patterns may be useful in evaluating the severity of multiple organ dysfunction syndrome in critically ill children and identifying those phenotypes with time-sensitive, treatable traits.

Detrimental effects of PCSK9 loss-of-function in the pediatric host response to sepsis are mediated through independent influence on Angiopoietin-1.

Background: Sepsis is associated with significant mortality, yet there are no efficacious therapies beyond antibiotics and supportive care. In adult sepsis studies, PCSK9 loss-of-function (LOF) and inhibition has shown therapeutic promise, likely through enhanced low-density lipoprotein receptor (LDLR) mediated endotoxin clearance. In contrast, we previously demonstrated higher mortality in septic juvenile hosts with PCSK9 LOF. In addition to direct influence on serum lipoprotein levels, PCSK9 likely exerts pleiotropic effects on vascular endothelium. Both mechanisms may influence sepsis outcomes. We sought to test the influence of PCSK9 LOF genotype on endothelial dysfunction in pediatric sepsis. Methods: Secondary analyses of a prospective observational cohort of pediatric septic shock. Single nucleotide polymorphisms of PCSK9 and LDLR genes were assessed. Serum PCSK9, lipoprotein, and endothelial marker concentrations were measured. Multivariable linear regression tested the influence of PCSK9 LOF genotype on endothelial markers, adjusted for age, complicated course, and low- and high-density lipoproteins (LDL and HDL). Causal mediation analyses assessed impact of select endothelial markers on the association between PCSK9 LOF genotype and mortality. Juvenile Pcsk9 null and wildtype mice were subject to cecal slurry sepsis and endothelial markers were quantified. Results: 474 patients were included. PCSK9 LOF was associated with several markers of endothelial dysfunction, with strengthening of associations after exclusion of patients homozygous for the rs688 LDLR variant that renders it insensitive to PCSK9. Serum PCSK9 levels did not correlate with endothelial dysfunction. PCSK9 LOF significantly influenced concentrations of Angiopoietin-1 (Angpt-1) and Vascular Cell Adhesion Molecule-1 (VCAM-1). However, upon adjusting for LDL and HDL, PCSK9 LOF remained significantly associated with low Angpt-1 alone. Causal Mediation Analysis demonstrated that the effect of PCSK9 LOF on mortality was partially mediated by Angpt-1 (p=0.0008). Murine data corroborated these results with lower Angpt-1 and higher soluble thrombomodulin among knockout mice with sepsis relative to the wildtype. Conclusions: PCSK9 LOF independently influences serum Angpt-1 levels in pediatric septic shock. Angpt-1 likely contributes mechanistically to the effect of PCSK9 LOF on mortality in juvenile hosts. Mechanistic studies on the role of PCSK9-LDLR pathway on vascular homeostasis may lead to the development of novel pediatric-specific sepsis therapies.

Executive Summary of the Second International Guidelines for the Diagnosis and Management of Pediatric Acute Respiratory Distress Syndrome (PALICC-2).

OBJECTIVES: We sought to update our 2015 work in the Second Pediatric Acute Lung Injury Consensus Conference (PALICC-2) guidelines for the diagnosis and management of pediatric acute respiratory distress syndrome (PARDS), considering new evidence and topic areas that were not previously addressed. DESIGN: International consensus conference series involving 52 multidisciplinary international content experts in PARDS and four methodology experts from 15 countries, using consensus conference methodology, and implementation science. SETTING: Not applicable. PATIENTS: Patients with or at risk for PARDS. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Eleven subgroups conducted systematic or scoping reviews addressing 11 topic areas: 1) definition, incidence, and epidemiology; 2) pathobiology, severity, and risk stratification; 3) ventilatory support; 4) pulmonary-specific ancillary treatment; 5) nonpulmonary treatment; 6) monitoring; 7) noninvasive respiratory support; 8) extracorporeal support; 9) morbidity and long-term outcomes; 10) clinical informatics and data science; and 11) resource-limited settings. The search included MEDLINE, EMBASE, and CINAHL Complete (EBSCOhost) and was updated in March 2022. Grading of Recommendations, Assessment, Development, and Evaluation methodology was used to summarize evidence and develop the recommendations, which were discussed and voted on by all PALICC-2 experts. There were 146 recommendations and statements, including: 34 recommendations for clinical practice; 112 consensus-based statements with 18 on PARDS definition, 55 on good practice, seven on policy, and 32 on research. All recommendations and statements had agreement greater than 80%. CONCLUSIONS: PALICC-2 recommendations and consensus-based statements should facilitate the implementation and adherence to the best clinical practice in patients with PARDS. These results will also inform the development of future programs of research that are crucially needed to provide stronger evidence to guide the pediatric critical care teams managing these patients.

Pathobiology, Severity, and Risk Stratification of Pediatric Acute Respiratory Distress Syndrome: From the Second Pediatric Acute Lung Injury Consensus Conference.

OBJECTIVES: To review the literature for studies published in children on the pathobiology, severity, and risk stratification of pediatric acute respiratory distress syndrome (PARDS) with the intent of guiding current medical practice and identifying important areas for future research related to severity and risk stratification. DATA SOURCES: Electronic searches of PubMed and Embase were conducted from 2013 to March 2022 by using a combination of medical subject heading terms and text words to capture the pathobiology, severity, and comorbidities of PARDS. STUDY SELECTION: We included studies of critically ill patients with PARDS that related to the severity and risk stratification of PARDS using characteristics other than the oxygenation defect. Studies using animal models, adult only, and studies with 10 or fewer children were excluded from our review. DATA EXTRACTION: Title/abstract review, full-text review, and data extraction using a standardized data collection form. DATA SYNTHESIS: The Grading of Recommendations Assessment, Development, and Evaluation approach was used to identify and summarize relevant evidence and develop recommendations for clinical practice. There were 192 studies identified for full-text extraction to address the relevant Patient/Intervention/Comparator/Outcome questions. One clinical recommendation was generated related to the use of dead space fraction for risk stratification. In addition, six research statements were generated about the impact of age on acute respiratory distress syndrome pathobiology and outcomes, addressing PARDS heterogeneity using biomarkers to identify subphenotypes and endotypes, and use of standardized ventilator, physiologic, and nonpulmonary organ failure measurements for future research. CONCLUSIONS: Based on an extensive literature review, we propose clinical management and research recommendations related to characterization and risk stratification of PARDS severity.

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.

Association of Pathogen Type With Outcomes of Children Encountering Community-Acquired Pediatric Septic Shock.

OBJECTIVES: To determine the association of pathogen type with mortality, functional status, and health-related quality of life (HRQL) among children at hospital discharge/1 month following hospitalization for septic shock. DESIGN: Secondary database analysis of a prospective, descriptive cohort investigation. SETTING: Twelve academic PICUs in the United States. PATIENTS: Critically ill children, 1 month to 18 years old, enrolled from 2013 to 2017. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Association of clinical outcomes with pathogen type was assessed for all patients and separately for surviving patients enrolled in the primary Life After Pediatric Sepsis Evaluation (LAPSE) investigation. For this secondary analysis, we predicted that age would be associated with pathogen type and outcomes, and accordingly, it was incorporated as a confounding variable in primary analyses. Among 389 children enrolled with septic shock, at 1 month/hospital discharge, we observed no statistically significant differences in relation to pathogen types for the composite outcome mortality or substantial new functional morbidity: no causative organism identified (27% [28/103]), pure viral infections (26% [24/91]), pure bacterial/fungal infections (25% [31/125]), and bacterial/fungal+viral coinfections (33% [23/70]). Similarly, we observed no statistically significant differences in relation to pathogen types for the composite outcome, mortality, or persistent serious deterioration of HRQL: no causative organism identified (43% [44/103]), pure viral infections (33% [30/91]), pure bacterial/fungal infections (46% [57/125]), and bacterial/fungal+viral coinfections (43% [30/70]). However, we did identify statistically significant associations between pathogen type and the outcome ventilator-free days ( p = 0.0083) and PICU-free days (0.0238). CONCLUSIONS: This secondary analysis of the LAPSE database identified no statistically significant association of pathogen type with composite mortality and morbidity outcomes. However, pathogen type may be associated with PICU resources employed to treat sepsis organ dysfunction. Ultimately, pediatric septic shock was frequently associated with adverse patient-centered, clinically meaningful outcomes regardless of infectious disease pathogen type.

Health Resource Use in Survivors of Pediatric Septic Shock in the United States.

OBJECTIVES: To evaluate postdischarge health resource use in pediatric survivors of septic shock and determine patient and hospitalization factors associated with health resource use. DESIGN: Secondary analyses of a multicenter prospective observational cohort study. SETTING: Twelve academic PICUs. PATIENTS: Children greater than or equal to 1 month and less than 18 years old hospitalized for community-acquired septic shock who survived to 1 year. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: For 308/338 patients (91%) with baseline and greater than or equal to one postdischarge survey, we evaluated readmission, emergency department (ED) visits, new medication class, and new device class use during the year after sepsis. Using negative binomial regression with bidirectional stepwise selection, we identified factors associated with each outcome. Median age was 7 years (interquartile range, 2-13), 157 (51%) had a chronic condition, and nearly all patients had insurance (private [n = 135; 44%] or government [n = 157; 51%]). During the year after sepsis, 128 patients (42%) were readmitted, 145 (47%) had an ED visit, 156 (51%) started a new medication class, and 102 (33%) instituted a new device class. Having a complex chronic condition was independently associated with readmission and ED visit. Documented infection and higher sum of Pediatric Logistic Organ Dysfunction--2 hematologic score were associated with readmission, whereas younger age and having a noncomplex chronic condition were associated with ED visit. Factors associated with new medication class use were private insurance, neurologic insult, and longer PICU stays. Factors associated with new device class use were preadmission chemotherapy or radiotherapy, presepsis Functional Status Scale score, and ventilation duration greater than or equal to 10 days. Of patients who had a new medication or device class, most had a readmission (56% and 61%) or ED visit (62% and 67%). CONCLUSIONS: Children with septic shock represent a high-risk cohort with high-resource needs after discharge. Interventions and targeted outcomes to mitigate postdischarge resource use may differ based on patients' preexisting conditions.

Differences in the Genomic Profiles of Immunoparalyzed and Nonimmunoparalyzed Children With Sepsis: A Pilot Study.

OBJECTIVES: Sepsis-induced immunoparalysis represents a pathologic downregulation of leukocyte function shown to be associated with adverse outcomes, although its mechanisms remain poorly understood. Our goal was to compare genome-wide gene expression profiles of immunoparalyzed and nonimmunoparalyzed children with sepsis to identify genes and pathways associated with immunoparalysis. DESIGN: Prospective observational study. PATIENTS: Twenty-six children with lower respiratory tract infection meeting criteria for sepsis, severe sepsis, or septic shock admitted to the PICU. SETTING: Two tertiary care PICUs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Innate immune function was assayed ex vivo by measuring release of tumor necrosis factor-α from whole blood after incubation with lipopolysaccharide for 4 hours. Immunoparalysis was defined as a tumor necrosis factor-α production capacity less than 200 pg/mL. Ten of the 26 children were immunoparalyzed. There were 17 significant differentially expressed genes when comparing genome-wide gene expression profiles of immunoparalyzed and nonimmunoparalyzed children (false discovery rate < 0.05). Nine genes showed increased expression in immunoparalyzed children (+1.5- to +8.8-fold change). Several of these dampen the immune system. Eight showed decreased expression in immunoparalyzed children (-1.7- to -3.9-fold change), several of which are involved in early regulation and activation of immune function. Functional annotation clustering using differentially expressed genes with p value of less than 0.05 showed three clusters related to immunity with significant enrichment scores (2.2-4.5); the most significant gene ontology terms in these clusters were antigen processing and presentation and negative regulation of interleukin-6 production. Network analysis identified potential protein interactions that may be involved in the development of immunoparalysis in children. CONCLUSIONS: In this exploratory analysis, immunoparalyzed children with sepsis showed increased expression of genes that dampen the immune system and decreased expression of genes involved in regulation and activation of the immune system. Analysis also implicated other proteins as potentially having as yet unidentified roles in the development of immunoparalysis.

Identification of phenotypes in paediatric patients with acute respiratory distress syndrome: a latent class analysis.

BACKGROUND: Previous latent class analysis of adults with acute respiratory distress syndrome (ARDS) identified two phenotypes, distinguished by the degree of inflammation. We aimed to identify phenotypes in children with ARDS in whom developmental differences might be important, using a latent class analysis approach similar to that used in adults. METHODS: This study was a secondary analysis of data aggregated from the Randomized Evaluation of Sedation Titration for Respiratory Failure (RESTORE) clinical trial and the Genetic Variation and Biomarkers in Children with Acute Lung Injury (BALI) ancillary study. We used latent class analysis, which included demographic, clinical, and plasma biomarker variables, to identify paediatric ARDS (PARDS) phenotypes within a cohort of children included in the RESTORE and BALI studies. The association of phenotypes with clinically relevant outcomes and the performance of paediatric data in adult ARDS classification algorithms were also assessed. FINDINGS: 304 children with PARDS were included in this secondary analysis. Using latent class analysis, a two-class model was a better fit for the cohort than a one-class model (p<0·001). Latent class analysis identified two classes: class 1 (181 [60%] of 304 patients with PARDS) and class 2 (123 [40%] of 304 patients with PARDS), referred to as phenotype 1 and 2 hereafter. Phenotype 2 was characterised by higher concentrations of inflammatory biomarkers, a higher incidence of vasopressor use, and more frequent diagnosis of sepsis, consistent with the adult hyperinflammatory phenotype. All levels of severity of PARDS were observed across both phenotypes. Children with the hyperinflammatory phenotype (phenotype 2) had worse clinical outcomes than those with the hypoinflammatory phenotype (phenotype 1), with a longer duration of mechanical ventilation (median 10·0 days [IQR 6·3-21·0] for phenotype 2 vs 6·6 days [4·1-10·8] for phenotype 1, p<0·0001), and higher incidence of mortality (17 [13·8%] of 123 patients vs four [2·2%] of 181 patients, p=0·0001). When using adult phenotype classification algorithms in children, the soluble tumour necrosis factor receptor-1 (sTNFr1), vasopressor use, and interleukin (IL)-6 variables gave an area under the curve (AUC) of 0·956, and the sTNFr1, vasopressor use, and IL-8 variables gave an AUC of 0·954, compared with the gold standard of latent class analysis. INTERPRETATION: Latent class analysis identified two phenotypes in children with ARDS with characteristics similar to those in adults, including worse outcomes among patients with the hyperinflammatory phenotype. PARDS phenotypes should be considered in design and analysis of future clinical trials in children. FUNDING: US National Institutes of Health.

Improvement in Health-Related Quality of Life After Community Acquired Pediatric Septic Shock.

Background: Although some pediatric sepsis survivors experience worsening health-related quality of life (HRQL), many return to their pre-illness HRQL. Whether children can improve beyond baseline is not known. We examined a cohort of pediatric sepsis survivors to determine if those with baseline HRQL scores below the population mean could exhibit ≥10% improvement and evaluated factors associated with improvement. Methods: In this secondary analysis of the Life After Pediatric Sepsis Evaluation prospective study, children aged 1 month to 18 years admitted to 12 academic PICUs in the United States with community-acquired septic shock who survived to 3 months and had baseline HRQL scores ≤ 80 (i.e., excluding those with good baseline HRQL to allow for potential improvement) were included. HRQL was measured using the Pediatric Quality of Life Inventory or Stein-Jessop Functional Status Scale. Findings: One hundred and seventeen children were eligible. Sixty-one (52%) had ≥ 10% improvement in HRQL by 3 months. Lower pre-sepsis HRQL was associated with increased odds of improvement at 3 months [aOR = 1.08, 95% CI (1.04-1.11), p < 0.001] and 12 months [OR = 1.05, 95% CI (1.02-1.11), p = 0.005]. Improvement in HRQL was most prevalent at 3 month follow-up; at 12 month follow-up, improvement was more sustained among children without severe developmental delay compared to children with severe developmental delay. Interpretation: More than half of these children with community acquired septic shock experienced at least a 10% improvement in HRQL from baseline to 3 months. Children with severe developmental delay did not sustain this improvement at 12 month follow-up.

Thrombomodulin is associated with increased mortality and organ failure in mechanically ventilated children with acute respiratory failure: biomarker analysis from a multicenter randomized controlled trial.

BACKGROUND: Acute respiratory failure (ARF) can progress to acute respiratory distress syndrome and death. Biomarkers may allow for risk stratification and prognostic enrichment in ARF. Thrombomodulin (TM) is a transmembrane antithrombotic mediator expressed in endothelial cells. It is cleaved into its soluble form (sTM) during inflammation and vascular injury. Levels of sTM correlate with inflammation and end organ dysfunction. METHODS: This was a prospective observational study of 432 patients aged 2 weeks-17 years requiring invasive mechanical ventilation. It was ancillary to the multicenter clinical trial, Randomized Evaluation of Sedation Titration for Respiratory Failure (RESTORE). After consent, patients had up to 3 plasma samples collected at 24-h intervals within 5 days after intubation. sTM was assayed by ELISA. The Hazard ratio (HR) for 90-day mortality was determined by Cox regression. Mixed effect models (MEM) were used to test for association with extrapulmonary multiorgan failure (MOF) and oxygenation index (OI). Age, race, sex and PRISM-III scores were used as confounding variables for multivariable analyses. RESULTS: sTM values ranged from 16.6 to 670.9 ng/ml within 5 days after intubation. Higher sTM was associated with increased 90-day mortality (n = 432, adjusted HR = 1.003, p = 0.02) and worse OI in the first 5 days after intubation (n = 252, Estimate = 0.02, p < 0.01). Both initial and slope of sTM were associated with increased extrapulmonary MOF in unadjusted and adjusted analyses (Intercept, Estimate = 0.003, p < 0.0001; and slope, Estimate = 0.01, p = 0.0009, n = 386). CONCLUSIONS: Plasma sTM is associated with mortality, severity of hypoxic respiratory failure and worsening extrapulmonary MOF in children with ARF. This suggests a role of vascular injury in the pathogenesis of ARF and provides potential applicability towards targeted therapies. TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT00814099 . In healthy lung endothelium, thrombomodulin (TM) recruits thrombin to activate Protein-C (PC/APC), that inhibits plasminogen activator-1 (PAI-1) and thrombosis. In inflamed and damaged endothelium, TM is cleaved into its soluble form (sTM), precluding its usual regulation of thrombosis. In this study, we measured plasma sTM levels in pediatric patients with respiratory failure and found that sTM correlated with mortality and other clinical markers of poor outcomes.

Inflammatory Biomarkers Are Associated With a Decline in Functional Status at Discharge in Children With Acute Respiratory Failure: An Exploratory Analysis.

To evaluate the link between early acute respiratory failure and functional morbidity in survivors using the plasma biomarkers interleukin-8, interleukin-1 receptor antagonist, thrombomodulin, and plasminogen activator inhibitor-1. We hypothesized that children with acute respiratory failure with higher levels of inflammation would have worse functional outcomes at discharge, as measured by Pediatric Overall Performance Category. DESIGN: Secondary analysis of the Genetic Variation and Biomarkers in Children with Acute Lung Injury (R01HL095410) study. SETTING: Twenty-two PICUs participating in the multisite clinical trial, Randomized Evaluation of Sedation Titration for Respiratory Failure (U01 HL086622) and the ancillary study (Biomarkers in Children with Acute Lung Injury). SUBJECTS: Children 2 weeks to 17 years requiring invasive mechanical ventilation for acute airways and/or parenchymal lung disease. Patients with an admission Pediatric Overall Performance Category greater than 3 (severe disability, coma, or brain death) were excluded. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among survivors, 387 patients had no worsening of Pediatric Overall Performance Category at discharge while 40 had worsening functional status, defined as any increase in Pediatric Overall Performance Category from baseline. There was no significant relationship between worsening of Pediatric Overall Performance Category and interleukin-8 or plasminogen activator inhibitor-1 on any day. There was no significant relationship between interleukin-1 receptor antagonist, or thrombomodulin, and worsening Pediatric Overall Performance Category on day 1. Plasma interleukin-1 receptor antagonist and thrombomodulin were significantly elevated on days 2 and 3 in those with worse functional status at discharge compared with those without. In multivariable analysis, interleukin-1 receptor antagonist and thrombomodulin were associated with a decline in functional status on days 2 and 3 after adjustment for age and highest oxygenation index. However, after adjusting for age and cardiovascular failure, only day 2 thrombomodulin levels were associated with a worsening in Pediatric Overall Performance Category. CONCLUSIONS: Higher levels of interleukin-1 receptor antagonist or thrombomodulin following intubation were associated with worse Pediatric Overall Performance Category scores at hospital discharge in children who survive acute respiratory failure. These data suggest that persistent inflammation may be related to functional decline.

Recalibration of the Renal Angina Index for Pediatric Septic Shock.

INTRODUCTION: Sepsis-associated acute kidney injury (AKI) is a common diagnosis in children that is associated with poor outcomes. The lack of therapeutic options once present makes early identification of at-risk patients essential. The renal angina index (RAI) has been previously validated to predict severe AKI in heterogeneous populations of critically ill children. The performance of this score specifically in children with septic shock is unknown. METHODS: A secondary analysis of a multicenter, prospective, observational study of 379 children with septic shock to determine the ability of the RAI to predict severe AKI at day 3, and to assess for the potential need for recalibration of the RAI in this unique subset of patients. RESULTS: At the original cutoff of ≥8, the RAI predicted day 3 severe AKI with an area under the receiving operating characteristic (AUROC) curve 0.90 (95% confidence interval [CI]: 0.86 to 93), 95% sensitivity, and 54% specificity. A Youden's index identified a higher optimal cutoff of ≥20 (sensitivity 83%, specificity 80%), and day 1 platelet count <150 × 103/µl was an independent predictor of severe AKI (adjusted odds ratio: 3.2; 95% CI: 1.7 to 6.3; P < 0.001). Recalibration of the RAI to include platelet count and this new threshold restored the sensitivity of the original ≥8 threshold (95%), while improving its specificity (69%). CONCLUSIONS: The RAI appears to be a sensitive and reliable tool for prediction of severe AKI in children with septic shock, although the use of a recalibrated sepsis-specific RAI using a higher cutoff and platelet count may be beneficial.

Health-Related Quality of Life After Community-Acquired Septic Shock in Children With Preexisting Severe Developmental Disabilities.

OBJECTIVES: To serially evaluate health-related quality of life during the first year after community-acquired septic shock in children with preexisting severe developmental disabilities and explore factors associated with health-related quality of life changes in these children. DESIGN: Secondary analysis of the Life after Pediatric Sepsis Evaluation investigation. SETTING: Twelve academic PICU in the United States. PATIENTS: Children greater than or equal to 1 month and less than 18 years old identified by their family caregiver (e.g., parent/guardian) as having severe developmental disability prior to septic shock. INTERVENTIONS: Family caregivers completed the Stein-Jessop Functional Status II-R Short Form as a measure of their child's health-related quality of life at baseline (reflecting preadmission status), day 7, and months 1, 3, 6, and 12 following PICU admission. Stein-Jessop Functional Status II-R Short Form scores were linearly transformed to a 0-100 scale, with higher scores indicating better health-related quality of life. MEASUREMENTS AND MAIN RESULTS: Of 392 Life after Pediatric Sepsis Evaluation participants, 137 were identified by their caregiver as having a severe developmental disability. Sixteen children (11.6%) with severe disability died during the 12 months following septic shock. Among 121 survivors, Stein-Jessop Functional Status II-R Short Form scores declined from preadmission baseline to day 7 (70.7 ± 16.1 vs 55.6 ± 19.2; p < 0.001). Stein-Jessop Functional Status II-R Short Form scores remained below baseline through month 12 (59.1 ± 21.0, p < 0.001 vs baseline). After adjusting for baseline Stein-Jessop Functional Status II-R Short Form, the caregiver being a single parent/guardian was associated with lower month 3 Stein-Jessop Functional Status II-R Short Form scores (p = 0.041). No other baseline child or caregiver characteristic, or critical illness-related factors were significantly associated with month 3 Stein-Jessop Functional Status II-R Short Form scores. CONCLUSIONS: Health-related quality of life among children with severe developmental disability remains, on average, below baseline during the first year following community-acquired septic shock. Children with severe disability and septic shock that are in single parent families are at increased risk. Clinical awareness of the potential for decline in health-related quality of life among disabled children is essential to prevent this adverse outcome from being missed.