Identification and transcriptomic assessment of latent profile pediatric septic shock phenotypes.

BACKGROUND: Sepsis poses a grave threat, especially among children, but treatments are limited owing to heterogeneity among patients. We sought to test the clinical and biological relevance of pediatric septic shock subclasses identified using reproducible approaches. METHODS: We performed latent profile analyses using clinical, laboratory, and biomarker data from a prospective multi-center pediatric septic shock observational cohort to derive phenotypes and trained a support vector machine model to assign phenotypes in an internal validation set. We established the clinical relevance of phenotypes and tested for their interaction with common sepsis treatments on patient outcomes. We conducted transcriptomic analyses to delineate phenotype-specific biology and inferred underlying cell subpopulations. Finally, we compared whether latent profile phenotypes overlapped with established gene-expression endotypes and compared survival among patients based on an integrated subclassification scheme. RESULTS: Among 1071 pediatric septic shock patients requiring vasoactive support on day 1 included, we identified two phenotypes which we designated as Phenotype 1 (19.5%) and Phenotype 2 (80.5%). Membership in Phenotype 1 was associated with ~ fourfold adjusted odds of complicated course relative to Phenotype 2. Patients belonging to Phenotype 1 were characterized by relatively higher Angiopoietin-2/Tie-2 ratio, Angiopoietin-2, soluble thrombomodulin (sTM), interleukin 8 (IL-8), and intercellular adhesion molecule 1 (ICAM-1) and lower Tie-2 and Angiopoietin-1 concentrations compared to Phenotype 2. We did not identify significant interactions between phenotypes, common treatments, and clinical outcomes. Transcriptomic analysis revealed overexpression of genes implicated in the innate immune response and driven primarily by developing neutrophils among patients designated as Phenotype 1. There was no statistically significant overlap between established gene-expression endotypes, reflective of the host adaptive response, and the newly derived phenotypes, reflective of the host innate response including microvascular endothelial dysfunction. However, an integrated subclassification scheme demonstrated varying survival probabilities when comparing patient endophenotypes. CONCLUSIONS: Our research underscores the reproducibility of latent profile analyses to identify 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.

High Variability in the Duration of Chest Compression Interruption is Associated With Poor Outcomes in Pediatric Extracorporeal Cardiopulmonary Resuscitation.

OBJECTIVES: To determine the association between chest compression interruption (CCI) patterns and outcomes in pediatric patients undergoing extracorporeal cardiopulmonary resuscitation (ECPR). DESIGN: Cardiopulmonary resuscitation (CPR) data were collected using defibrillator-electrode and bedside monitor waveforms from pediatric ECPR cases between 2013 and 2021. Duration and variability of CCI during cannulation for ECPR was determined and compared with survival to discharge using Fishers exact test and logistic regressions with cluster-robust se s for adjusted analyses. SETTING: Quaternary care children's hospital. PATIENTS: Pediatric patients undergoing ECPR. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 41 ECPR events, median age was 0.7 years (Q1, Q3: 0.1, 5.4), 37% (15/41) survived to hospital discharge with 73% (11/15) of survivors having a favorable neurologic outcome. Median duration of CPR from start of ECPR cannulation procedure to initiation of extracorporeal membrane oxygenation (ECMO) flow was 21 minutes (18, 30). Median duration of no-flow times associated with CCI during ECMO cannulation was 11 seconds (5, 28). Following planned adjustment for known confounders, survival to discharge was inversely associated with maximum duration of CCI (odds ratio [OR] 0.91 [0.86-0.95], p = 0.04) as well as the variability in the CCI duration (OR 0.96 [0.93-0.99], p = 0.04). Cases with both above-average CCI duration and higher CCI variability ( sd > 30 s) were associated with lowest survival (12% vs. 54%, p = 0.009). Interaction modeling suggests that lower variability in CCI is associated with improved survival, especially in cases where average CCI durations are higher. CONCLUSIONS: Shorter duration of CCI and lower variability in CCI during cannulation for ECPR were associated with survival following refractory pediatric cardiac arrest.

Biomarker Assessment of a High-Risk, Data-Driven Pediatric Sepsis Phenotype Characterized by Persistent Hypoxemia, Encephalopathy, and Shock.

OBJECTIVES: Identification of children with sepsis-associated multiple organ dysfunction syndrome (MODS) at risk for poor outcomes remains a challenge. We sought to the determine reproducibility of the data-driven "persistent hypoxemia, encephalopathy, and shock" (PHES) phenotype and determine its association with inflammatory and endothelial biomarkers, as well as biomarker-based pediatric risk strata. DESIGN: We retrained and validated a random forest classifier using organ dysfunction subscores in the 2012-2018 electronic health record (EHR) dataset used to derive the PHES phenotype. We used this classifier to assign phenotype membership in a test set consisting of prospectively (2003-2023) enrolled pediatric septic shock patients. We compared profiles of the PERSEVERE family of biomarkers among those with and without the PHES phenotype and determined the association with established biomarker-based mortality and MODS risk strata. SETTING: Twenty-five PICUs across the United States. PATIENTS: EHR data from 15,246 critically ill patients with sepsis-associated MODS split into derivation and validation sets and 1,270 pediatric septic shock patients in the test set of whom 615 had complete biomarker data. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The area under the receiver operator characteristic curve of the modified classifier to predict PHES phenotype membership was 0.91 (95% CI, 0.90-0.92) in the EHR validation set. In the test set, PHES phenotype membership was associated with both increased adjusted odds of complicated course (adjusted odds ratio [aOR] 4.1; 95% CI, 3.2-5.4) and 28-day mortality (aOR of 4.8; 95% CI, 3.11-7.25) after controlling for age, severity of illness, and immunocompromised status. Patients belonging to the PHES phenotype were characterized by greater degree of systemic inflammation and endothelial activation, and were more likely to be stratified as high risk based on PERSEVERE biomarkers predictive of death and persistent MODS. CONCLUSIONS: The PHES trajectory-based phenotype is reproducible, independently associated with poor clinical outcomes, and overlapped with higher risk strata based on prospectively validated biomarker approaches.

Diagnostic Validation of the Updated Pediatric Sepsis Biomarker Risk II for Acute Kidney Injury Prediction Model in Pediatric Septic Shock.

OBJECTIVES: We previously derived the updated Pediatric Sepsis Biomarker Risk for Acute Kidney Injury (PERSEVERE-II AKI) prediction model, which had robust diagnostic test characteristics for severe AKI on day 3 (D3 severe AKI) of septic shock. We now sought to validate this model in an independent cohort of children to the one in which the model was developed. DESIGN: A secondary analysis of a multicenter, prospective, observational study carried out from January 2019 to December 2022. SETTING: Ten PICUs in the United States. PATIENTS: Children with septic shock 1 week to 18 years old admitted to the PICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Seventy-nine of 363 patients (22%) had D3 severe AKI, defined as Kidney Disease Improving Global Outcomes stage 2 or higher. Patients were assigned a probability of D3 severe AKI using the PERSEVERE-II AKI model. The model predicted D3 severe AKI with an area under the receiver operating characteristic curve of 0.89 (95% CI, 0.85-0.93), sensitivity of 77% (95% CI, 66-86%), specificity of 88% (95% CI, 84-92%), positive predictive value of 65% (95% CI, 54-74%), and negative predictive value of 93% (95% CI, 89-96%). These data represent an increase in post-test probability of D3 severe AKI with a positive test from 22% to 65%, and a prevalence threshold of 28%. On multivariable regression, the PERSEVERE-II AKI prediction model demonstrated greater adjusted odds ratio (aOR) for D3 severe AKI (aOR, 11.2; 95% CI, 4.9-25.3) and lesser aOR for failure of D3 renal recovery from early AKI (aOR, 0.31; 95% CI, 0.13-0.69). CONCLUSIONS: The PERSEVERE-II AKI model demonstrates consistently robust performance for prediction of new or persistent D3 severe AKI in children with septic shock. A major limitation is that actual D3 severe AKI prevalence is below the prevalence threshold for the test, and thus future work should focus on evaluating use in enriched populations.

Executive Summary: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE (PEACE) Consensus Conference.

OBJECTIVES: To present recommendations and consensus statements with supporting literature for the clinical management of neonates and children supported with extracorporeal membrane oxygenation (ECMO) from the Pediatric ECMO Anticoagulation CollaborativE (PEACE) consensus conference. DATA SOURCES: Systematic review was performed using PubMed, Embase, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021, followed by serial meetings of international, interprofessional experts in the management ECMO for critically ill children. STUDY SELECTION: The management of ECMO anticoagulation for critically ill children. DATA EXTRACTION: Within each of eight subgroup, two authors reviewed all citations independently, with a third independent reviewer resolving any conflicts. DATA SYNTHESIS: A systematic review was conducted using MEDLINE, Embase, and Cochrane Library databases, from January 1988 to May 2021. Each panel developed evidence-based and, when evidence was insufficient, expert-based statements for the clinical management of anticoagulation for children supported with ECMO. These statements were reviewed and ratified by 48 PEACE experts. Consensus was obtained using the Research and Development/UCLA Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed 23 recommendations, 52 expert consensus statements, and 16 good practice statements covering the management of ECMO anticoagulation in three broad categories: general care and monitoring; perioperative care; and nonprocedural bleeding or thrombosis. Gaps in knowledge and research priorities were identified, along with three research focused good practice statements. CONCLUSIONS: The 91 statements focused on clinical care will form the basis for standardization and future clinical trials.

Drp1/p53 interaction mediates p53 mitochondrial localization and dysfunction in septic cardiomyopathy.

BACKGROUND: Previous studies have implicated p53-dependent mitochondrial dysfunction in sepsis induced end organ injury, including sepsis-induced myocardial dysfunction (SIMD). However, the mechanisms behind p53 localization to the mitochondria have not been well established. Dynamin-related protein 1 (Drp1), a mediator of mitochondrial fission, may play a role in p53 mitochondrial localization. Here we examined the role of Drp1/p53 interaction in SIMD using in vitro and murine models of sepsis. METHODS: H9c2 cardiomyoblasts and BALB/c mice were exposed to lipopolysaccharide (LPS) to model sepsis phenotype. Pharmacologic inhibitors of Drp1 activation (ψDrp1) and of p53 mitochondrial binding (pifithrin µ, PFTµ) were utilized to assess interaction between Drp1 and p53, and the subsequent downstream impact on mitochondrial morphology and function, cardiomyocyte function, and sepsis phenotype. RESULTS: Both in vitro and murine models demonstrated an increase in physical Drp1/p53 interaction following LPS treatment, which was associated with increased p53 mitochondrial localization, and mitochondrial dysfunction. This Drp1/p53 interaction was inhibited by ΨDrp1, suggesting that this interaction is dependent on Drp1 activation. Treatment of H9c2 cells with either ΨDrp1 or PFTµ inhibited the LPS mediated localization of Drp1/p53 to the mitochondria, decreased oxidative stress, improved cellular respiration and ATP production. Similarly, treatment of BALB/c mice with either ΨDrp1 or PFTµ decreased LPS-mediated mitochondrial localization of p53, mitochondrial ROS in cardiac tissue, and subsequently improved cardiomyocyte contractile function and survival. CONCLUSION: Drp1/p53 interaction and mitochondrial localization is a key prodrome to mitochondrial damage in SIMD and inhibiting this interaction may serve as a therapeutic target.

Prediction of Difficult Laryngoscopy Using Ultrasound: A Systematic Review and Meta-Analysis.

OBJECTIVES: Evaluate associations between ultrasound measures and difficult laryngoscopy. DATA SOURCES: MEDLINE, Embase, Google Scholar, Web of Science, and the Cochrane Library were searched using MeSH terms and keywords. STUDY SELECTION: Studies published in English describing the use of airway ultrasound for identifying difficult laryngoscopy, with sufficient data to calculate sensitivity and specificity using 2 × 2 tables. DATA EXTRACTION: We assigned the described indices of airway dimension to one of three domains based on methodology characteristics: anterior tissue thickness domain, anatomical position domain, and oral space domain. We then performed a bivariate random-effects meta-analysis, deriving pooled sensitivity, specificity, diagnostic odds ratio, positive likelihood ratio, and negative likelihood ratio estimates. We assessed risks of bias using Quality Assessment of Diagnostic Accuracy Studies-2 analysis. DATA SYNTHESIS: Thirty-three studies evaluating 27 unique indices were included in the meta-analysis. The ultrasound protocols of the included studies were heterogeneous. Anterior tissue thickness demonstrated a pooled sensitivity of 76% (95% CI, 71-81%), specificity of 77% (95% CI, 72-81%), and an area under the receiver operating characteristic curve (AUROC) of 0.83 (95% CI, 0.80-0.86). Anatomical position demonstrated a pooled sensitivity of 74% (95% CI, 61-84%), specificity of 86% (95% CI, 78-91%), and an AUROC of 0.87 (95% CI, 0.84-0.90). Oral space demonstrated a pooled sensitivity of 53% (95% CI, 0.36-0.69), specificity of 77% (95% CI, 0.67-0.85), and an AUROC of 0.73 (95% CI, 0.69-0.77). CONCLUSIONS: Airway ultrasound metrics associate with difficult laryngoscopy in three domains: anterior tissue thickness, anatomic position, and oral space. An assessment instrument combining clinical and ultrasound assessments may be an accurate screening tool for difficult laryngoscopy.

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.

External validation of the modified sepsis renal angina index for prediction of severe acute kidney injury in children with septic shock.

BACKGROUND: Acute kidney injury (AKI) occurs commonly in pediatric septic shock and increases morbidity and mortality. Early identification of high-risk patients can facilitate targeted intervention to improve outcomes. We previously modified the renal angina index (RAI), a validated AKI prediction tool, to improve specificity in this population (sRAI). Here, we prospectively assess sRAI performance in a separate cohort. METHODS: A secondary analysis of a prospective, multicenter, observational study of children with septic shock admitted to the pediatric intensive care unit from 1/2019 to 12/2022. The primary outcome was severe AKI (≥ KDIGO Stage 2) on Day 3 (D3 severe AKI), and we compared predictive performance of the sRAI (calculated on Day 1) to the original RAI and serum creatinine elevation above baseline (D1 SCr > Baseline +). Original renal angina fulfillment (RAI +) was defined as RAI ≥ 8; sepsis renal angina fulfillment (sRAI +) was defined as RAI ≥ 20 or RAI 8 to < 20 with platelets < 150 × 103/µL. RESULTS: Among 363 patients, 79 (22%) developed D3 severe AKI. One hundred forty (39%) were sRAI + , 195 (54%) RAI + , and 253 (70%) D1 SCr > Baseline + . Compared to sRAI-, sRAI + had higher risk of D3 severe AKI (RR 8.9, 95%CI 5-16, p < 0.001), kidney replacement therapy (KRT) (RR 18, 95%CI 6.6-49, p < 0.001), and mortality (RR 2.5, 95%CI 1.2-5.5, p = 0.013). sRAI predicted D3 severe AKI with an AUROC of 0.86 (95%CI 0.82-0.90), with greater specificity (74%) than D1 SCr > Baseline (36%) and RAI + (58%). On multivariable regression, sRAI + retained associations with D3 severe AKI (aOR 4.5, 95%CI 2.0-10.2, p < 0.001) and need for KRT (aOR 5.6, 95%CI 1.5-21.5, p = 0.01). CONCLUSIONS: Prediction of severe AKI in pediatric septic shock is important to improve outcomes, allocate resources, and inform enrollment in clinical trials examining potential disease-modifying therapies. The sRAI affords more accurate and specific prediction than context-free SCr elevation or the original RAI in this population.

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.

Serum renin and prorenin concentrations predict severe persistent acute kidney injury and mortality in pediatric septic shock.

BACKGROUND: Studies in critically ill adults demonstrate associations between serum renin concentrations (a proposed surrogate for renin-angiotensin-aldosterone system dysregulation) and poor outcomes, but data in critically ill children are lacking. We assessed serum renin + prorenin concentrations in children with septic shock to determine their predictive ability for acute kidney injury (AKI) and mortality. METHODS: We conducted a secondary analysis of a multicenter observational study of children aged 1 week to 18 years admitted to 14 pediatric intensive care units (PICUs) with septic shock and residual serum available for renin + prorenin measurement. Primary outcomes were development of severe persistent AKI (≥ KDIGO stage 2 for ≥ 48 h) in the first week and 28-day mortality. RESULTS: Among 233 patients, day 1 median renin + prorenin concentration was 3436 pg/ml (IQR 1452-6567). Forty-two (18%) developed severe persistent AKI and 32 (14%) died. Day 1 serum renin + prorenin predicted severe persistent AKI with an AUROC of 0.75 (95% CI 0.66-0.84, p < 0.0001; optimal cutoff 6769 pg/ml) and mortality with an AUROC of 0.79 (95% CI 0.69-0.89, p < 0.0001; optimal cutoff 6521 pg/ml). Day 3/day 1 (D3:D1) renin + prorenin ratio had an AUROC of 0.73 (95% CI 0.63-0.84, p < 0.001) for mortality. On multivariable regression, day 1 renin + prorenin > optimal cutoff retained associations with severe persistent AKI (aOR 6.8, 95% CI 3.0-15.8, p < 0.001) and mortality (aOR 6.9, 95% CI 2.2-20.9, p < 0.001). Similarly, D3:D1 renin + prorenin > optimal cutoff was associated with mortality (aOR 7.6, 95% CI 2.5-23.4, p < 0.001). CONCLUSIONS: Children with septic shock have very elevated serum renin + prorenin concentrations on PICU admission, and these concentrations, as well as their trend over the first 72 h, predict severe persistent AKI and mortality. A higher resolution version of the Graphical abstract is available as Supplementary information.

Drp1/Fis1-Dependent Pathologic Fission and Associated Damaged Extracellular Mitochondria Contribute to Macrophage Dysfunction in Endotoxin Tolerance.

OBJECTIVES: Recent publications have shown that mitochondrial dynamics can govern the quality and quantity of extracellular mitochondria subsequently impacting immune phenotypes. This study aims to determine if pathologic mitochondrial fission mediated by Drp1/Fis1 interaction impacts extracellular mitochondrial content and macrophage function in sepsis-induced immunoparalysis. DESIGN: Laboratory investigation. SETTING: University laboratory. SUBJECTS: C57BL/6 and BALB/C mice. INTERVENTIONS: Using in vitro and murine models of endotoxin tolerance (ET), we evaluated changes in Drp1/Fis1-dependent pathologic fission and simultaneously measured the quantity and quality of extracellular mitochondria. Next, by priming mouse macrophages with isolated healthy mitochondria (MC) and damaged mitochondria, we determined if damaged extracellular mitochondria are capable of inducing tolerance to subsequent endotoxin challenge. Finally, we determined if inhibition of Drp1/Fis1-mediated pathologic fission abrogates release of damaged extracellular mitochondria and improves macrophage response to subsequent endotoxin challenge. MEASUREMENTS AND MAIN RESULTS: When compared with naïve macrophages (NMs), endotoxin-tolerant macrophages (ETM) demonstrated Drp1/Fis1-dependent mitochondrial dysfunction and higher levels of damaged extracellular mitochondria (Mitotracker-Green + events/50 µL: ETM = 2.42 × 106 ± 4,391 vs NM = 5.69 × 105 ± 2,478; p < 0.001). Exposure of NMs to damaged extracellular mitochondria (MH) induced cross-tolerance to subsequent endotoxin challenge, whereas MC had minimal effect (tumor necrosis factor [TNF]-α [pg/mL]: NM = 668 ± 3, NM + MH = 221 ± 15, and NM + Mc = 881 ± 15; p < 0.0001). Inhibiting Drp1/Fis1-dependent mitochondrial fission using heptapeptide (P110), a selective inhibitor of Drp1/Fis1 interaction, improved extracellular mitochondrial function (extracellular mitochondrial membrane potential, JC-1 [R/G] ETM = 7 ± 0.5 vs ETM + P110 = 19 ± 2.0; p < 0.001) and subsequently improved immune response in ETMs (TNF-α [pg/mL]; ETM = 149 ± 1 vs ETM + P110 = 1,150 ± 4; p < 0.0001). Similarly, P110-treated endotoxin tolerant mice had lower amounts of damaged extracellular mitochondria in plasma (represented by higher extracellular mitochondrial membrane potential, TMRM/MT-G: endotoxin tolerant [ET] = 0.04 ± 0.02 vs ET + P110 = 0.21 ± 0.02; p = 0.03) and improved immune response to subsequent endotoxin treatment as well as cecal ligation and puncture. CONCLUSIONS: Inhibition of Drp1/Fis1-dependent mitochondrial fragmentation improved macrophage function and immune response in both in vitro and in vivo models of ET. This benefit is mediated, at least in part, by decreasing the release of damaged extracellular mitochondria, which contributes to endotoxin cross-tolerance. Altogether, these data suggest that alterations in mitochondrial dynamics may play an important role in sepsis-induced immunoparalysis.

Ultrasound education improves safety for peripheral intravenous catheter insertion in critically ill children.

BACKGROUND: Difficulty in obtaining peripheral vascular access is a common problem in patients admitted to the pediatric intensive care unit (PICU). The use of ultrasound guidance can improve the overall success in obtaining vascular access. This study evaluated the success and longevity of PIV placement by nurses pre- and post-implementation of an USGPIV curriculum. METHODS: PICU nurses participated in a prospective quality improvement study. Each participating nurse attempted 10 PIVs by using landmark (LM) methods. The same nurses then received individual instruction in an USGPIV placement curriculum. Following the educational intervention, each nurse attempted 10 USGPIVs. RESULTS: A total of 150 LM PIVs and 143 USGPIVs were attempted. The first stick success in the post-intervention (USGPIV) group was 85.9% compared to 47.3% in the pre-intervention (LM) group (p < 0.001). Overall success was also superior in the USGPIV group (94.3 versus 57.3%, respectively; p < 0.001). PIVs placed by US lasted longer with a median survival time of 4 ± 3.84 days versus 3 ± 3.51 days for LM PIVs (p < 0.050, log-rank test). CONCLUSIONS: Successful implementation of a standardized curriculum for USGPIV placement for PICU nurses improves first stick, overall success, and longevity of PIV catheter placement. IMPACT: An ultrasound-guided IV curriculum can be successfully implemented resulting in increased first stick success and increased longevity. Registered nurses can be trained in placement of ultrasound-guided IV placement. This study provides a training curriculum for ultrasound-guided IV placement that can be applied to other settings or institutions.

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.

Laryngeal Ultrasound Detects Vocal Fold Immobility in Adults: A Systematic Review.

Laryngeal ultrasound (US) is becoming widely accepted for assessing true vocal fold immobility (TVFI), a potential complication of laryngeal and thyroid surgery. The objective of this project is to perform a systematic review and meta-analysis of pooled evidence surrounding laryngeal US as a modality for diagnosing TVFI in adults at risk for the condition in comparison to laryngoscopy as a gold standard. Medical subject heading terms were used to search MEDLINE, Embase, Google Scholar, Web of Science, and the Cochrane Library for relevant citations from January 1, 2000, to June 30, 2020. Studies were included if they involved patients 16 years and older, where laryngeal US was compared to laryngoscopy for TVFI. Studies were excluded if there were insufficient data to compute a sensitivity/specificity table after attempting to contact the authors. Case reports, and case series were also excluded. The initial search returned 1357 citations. Of these, 109 were selected for review utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Thirty citations describing 6033 patients were included in the final meta-analysis. A bivariate random effects meta-analysis was performed, revealing a pooled sensitivity for laryngeal US of 0.95 (95% confidence interval [CI] 0.88-0.98), a specificity of 0.99 (95% CI 0.97-0.99), and a diagnostic odds ratio of 1328.2 (95% CI 294.0-5996.5). The area under the curve of the hierarchical summary receiver operating characteristic curve was 0.99 (95% CI 0.98-1.00). Laryngeal US demonstrates high sensitivity and specificity for detecting VFI in the hands of clinicians directly providing care to patients.

Western diet regulates immune status and the response to LPS-driven sepsis independent of diet-associated microbiome.

Sepsis is a deleterious immune response to infection that leads to organ failure and is the 11th most common cause of death worldwide. Despite plaguing humanity for thousands of years, the host factors that regulate this immunological response and subsequent sepsis severity and outcome are not fully understood. Here we describe how the Western diet (WD), a diet high in fat and sucrose and low in fiber, found rampant in industrialized countries, leads to worse disease and poorer outcomes in an LPS-driven sepsis model in WD-fed mice compared with mice fed standard fiber-rich chow (SC). We find that WD-fed mice have higher baseline inflammation (metaflammation) and signs of sepsis-associated immunoparalysis compared with SC-fed mice. WD mice also have an increased frequency of neutrophils, some with an "aged" phenotype, in the blood during sepsis compared with SC mice. Importantly, we found that the WD-dependent increase in sepsis severity and higher mortality is independent of the microbiome, suggesting that the diet may be directly regulating the innate immune system through an unknown mechanism. Strikingly, we could predict LPS-driven sepsis outcome by tracking specific WD-dependent disease factors (e.g., hypothermia and frequency of neutrophils in the blood) during disease progression and recovery. We conclude that the WD is reprogramming the basal immune status and acute response to LPS-driven sepsis and that this correlates with alternative disease paths that lead to more severe disease and poorer outcomes.

Implementation of a Bedside Point-of-Care Ultrasound Program in a Large Academic Neonatal Intensive Care Unit.

OBJECTIVE: In the adult and pediatric critical care population, point-of-care ultrasound (POCUS) can aid in diagnosis, patient management, and procedural accuracy. For neonatal providers, training in ultrasound and the use of ultrasound for diagnosis and management is increasing, but use in the neonatal intensive care unit (NICU) is still uncommon compared with other critical care fields. Our objective was to describe the process of implementing a POCUS program in a large academic NICU and evaluate the role of ultrasound in neonatal care during early adaption of this program. STUDY DESIGN: A POCUS program established in December 2018 included regular bedside scanning, educational sessions, and quality assurance, in collaboration with members of the cardiology, radiology, and pediatric critical care divisions. Core applications were determined, and protocols outlined guidelines for image acquisition. An online database included images and descriptive logs for each ultrasound. RESULTS: A total of 508 bedside ultrasounds (76.8% diagnostic and 23.2% procedural) were performed by 23 providers from December 2018 to December 2020 in five core diagnostic applications: umbilical line visualization, cardiac, lung, abdomen (including bladder), and cranial as well as procedural applications. POCUS guided therapy and influenced clinical management in all applications: umbilical line assessment (26%), cardiac (33%), lung (14%), abdomen (53%), and cranial (43%). With regard to procedural ultrasound, 74% of ultrasound-guided arterial access and 89% of ultrasound-guided lumbar punctures were successful. CONCLUSIONS: Implementation of a POCUS program is feasible in a large academic NICU and can benefit from a team approach. Establishing a program in any NICU requires didactic opportunities, a defined scope of practice, and imaging review with quality assurance. Bedside clinician performed ultrasound findings can provide valuable information in the NICU and impact clinical management. KEY POINTS: · Use of point-of-care ultrasound is increasing in neonatology and has been shown to improve patient care.. · Implementation of a point-of-care ultrasound program requires the definition of scope of practice and can benefit from the support of other critical care and imaging departments and providers.. · Opportunities for point-of-care ultrasound didactics, imaging review, and quality assurance can enhance the utilization of bedside ultrasound..

Estimating filling pressures in paediatric heart transplant recipients using echocardiographic parameters and B-type natriuretic peptide.

BACKGROUND: Longitudinal evaluation of allograft diastolic function in paediatric heart transplant recipients is important for early detection of acute rejection, cardiac allograft vasculopathy, and graft dysfunction. Mean diastolic right atrial and pulmonary capillary wedge pressures obtained at catheterisation are the reference standards for assessment. Echocardiography is non-invasive and more suitable for serial surveillance, but individual parameters have lacked accuracy. This study aimed to identify covariates of post-transplant mean right atrial and pulmonary capillary wedge pressures, including B-type natriuretic peptide and certain echocardiographic parameters. METHODS: A retrospective review of 143 scheduled cardiac catheterisations and echocardiograms from 56 paediatric recipients transplanted from 2007 to 2011 was performed. Samples with rejection were excluded. Univariate and multivariate linear regression models using backward selection were applied to a database consisting of B-type natriuretic peptide, haemodynamic, and echocardiographic data. RESULTS: Ln B-type natriuretic peptide, heart rate z-score, left ventricular end-diastolic dimension z-score, mitral E/e', and percent interventricular septal thickening in systole were independently associated with mean right atrial pressure. Ln B-type natriuretic peptide, heart rate z-score, left ventricular end-diastolic dimension z-score, left ventricular mass (observed/predicted), and mitral E/e' were independently associated with mean pulmonary capillary wedge pressure. Covariates of B-type natriuretic peptide included mean pulmonary artery and pulmonary capillary wedge pressures, height, haemoglobin, fractional shortening, percent interventricular septal thickening in systole, and pulmonary vascular resistance index. CONCLUSIONS: B-type natriuretic peptide and echocardiographic indices of diastolic function were independently related to post-transplant mean right atrial and pulmonary capillary wedge pressures in paediatric heart transplant recipients without rejection.

Regulating Critical Care Ultrasound, It Is All in the Interpretation.

Point-of-care ultrasound (POCUS) use is rapidly expanding as a practice in adult and pediatric critical care environments. In January 2020, the Joint Commission endorsed a statement from the Emergency Care Research Institute citing point-of-care ultrasound as a potential hazard to patients for reasons related to training and skill verification, oversight of use, and recordkeeping and accountability mechanisms for clinical use; however, no evidence was presented to support these concerns. Existing data on point-of-care ultrasound practices in pediatric critical care settings verify that point-of-care ultrasound use continues to increase, and contrary to the concerns raised, resources are becoming increasingly available for point-of-care ultrasound use. Many institutions have recognized a successful approach to addressing these concerns that can be achieved through multispecialty collaborations.

Assessment of Vocal Cord Motion Using Laryngeal Ultrasound in Children: A Systematic Review and Meta-Analysis.

OBJECTIVES: Laryngeal ultrasound is a nonirradiating, noninvasive method for assessing the upper airway in children. This systematic review and meta-analysis examine available evidence for accuracy of laryngeal ultrasound in diagnosing vocal cord immobility in infants and children after surgery and trauma affecting the vocal cords. DESIGN: Medical subject heading terms were used to search MEDLINE, Embase, Google Scholar, Web of Science, and the Cochrane Library for relevant citations. Publications from January 1, 2000, to June 30, 2020 were included in the search strategy. Study inclusion criteria consisted of randomized control trials and nonrandomized retrospective or prospective observational studies where vocal cord motion was evaluated by laryngeal ultrasound and compared with a reference test. Studies were excluded if there was insufficient data to compute a sensitivity/specificity table. Case reports, case series less than 10, and manuscripts not published in English were also excluded. PATIENTS: Studies which included subjects younger than or equal to 18 years were considered for full article review. SETTINGS: No restrictions on study settings were imposed in this systematic review. MEASUREMENTS AND MAIN RESULTS: The initial search returned 1,357 citations. After de-duplication, abstract, and full review, eight citations were included in the final meta-analysis. A bivariate random-effects meta-analysis was performed, which revealed a pooled sensitivity for laryngeal ultrasound in detecting vocal cord immobility of 91% (95% CI, 83-95%), specificity of 97% (95% CI, 82-100%), diagnostic odds ratio 333.56 (95% CI, 34.00-3,248.71), positive likelihood ratio 31.58 (95% CI, 4.50-222.05), and negative likelihood ratio 0.09 (95% CI, 0.05-0.19). CONCLUSIONS: Laryngeal ultrasound demonstrates high sensitivity and specificity for detecting vocal cord motion in children in a wide range of clinical settings. Laryngeal ultrasound offers a low-risk imaging option for assessing vocal cord function in children compared with the current gold standard of laryngoscopy.