Modeling T Cell Fate.

Many of the pathways that underlie the diversification of naive T cells into effector and memory subsets, and the maintenance of these populations, remain controversial. In recent years a variety of experimental tools have been developed that allow us to follow the fates of cells and their descendants. In this review we describe how mathematical models provide a natural language for describing the growth, loss, and differentiation of cell populations. By encoding mechanistic descriptions of cell behavior, models can help us interpret these new datasets and reveal the rules underpinning T cell fate decisions, both at steady state and during immune responses.

Site-specific development and progressive maturation of human tissue-resident memory T cells over infancy and childhood.

Infancy and childhood are critical life stages for generating immune memory to protect against pathogens; however, the timing, location, and pathways for memory development in humans remain elusive. Here, we investigated T cells in mucosal sites, lymphoid tissues, and blood from 96 pediatric donors aged 0-10 years using phenotypic, functional, and transcriptomic profiling. Our results revealed that memory T cells preferentially localized in the intestines and lungs during infancy and accumulated more rapidly in mucosal sites compared with blood and lymphoid organs, consistent with site-specific antigen exposure. Early life mucosal memory T cells exhibit distinct functional capacities and stem-like transcriptional profiles. In later childhood, they progressively adopt proinflammatory functions and tissue-resident signatures, coincident with increased T cell receptor (TCR) clonal expansion in mucosal and lymphoid sites. Together, our findings identify staged development of memory T cells targeted to tissues during the formative years, informing how we might promote and monitor immunity in children.

Longitudinal profiling of respiratory and systemic immune responses reveals myeloid cell-driven lung inflammation in severe COVID-19.

Immune response dynamics in coronavirus disease 2019 (COVID-19) and their severe manifestations have largely been studied in circulation. Here, we examined the relationship between immune processes in the respiratory tract and circulation through longitudinal phenotypic, transcriptomic, and cytokine profiling of paired airway and blood samples from patients with severe COVID-19 relative to heathy controls. In COVID-19 airways, T cells exhibited activated, tissue-resident, and protective profiles; higher T cell frequencies correlated with survival and younger age. Myeloid cells in COVID-19 airways featured hyperinflammatory signatures, and higher frequencies of these cells correlated with mortality and older age. In COVID-19 blood, aberrant CD163+ monocytes predominated over conventional monocytes, and were found in corresponding airway samples and in damaged alveoli. High levels of myeloid chemoattractants in airways suggest recruitment of these cells through a CCL2-CCR2 chemokine axis. Our findings provide insights into immune processes driving COVID-19 lung pathology with therapeutic implications for targeting inflammation in the respiratory tract.

The dynamics and longevity of circulating CD4+ memory T cells depend on cell age and not the chronological age of the host.

Quantifying the kinetics with which memory T cell populations are generated and maintained is essential for identifying the determinants of the duration of immunity. The quality and persistence of circulating CD4 effector memory (TEM) and central memory (TCM) T cells in mice appear to shift with age, but it is unclear whether these changes are driven by the aging host environment, by cell age effects, or both. Here, we address these issues by combining DNA labelling methods, established fate-mapping systems, a novel reporter mouse strain, and mathematical models. Together, these allow us to quantify the dynamics of both young and established circulating memory CD4 T cell subsets, within both young and old mice. We show that that these cells and their descendents become more persistent the longer they reside within the TCM and TEM pools. This behaviour may limit memory CD4 T cell diversity by skewing TCR repertoires towards clones generated early in life, but may also compensate for functional defects in new memory cells generated in old age.

Pervasive lesion segregation shapes cancer genome evolution.

Cancers arise through the acquisition of oncogenic mutations and grow by clonal expansion1,2. Here we reveal that most mutagenic DNA lesions are not resolved into a mutated DNA base pair within a single cell cycle. Instead, DNA lesions segregate, unrepaired, into daughter cells for multiple cell generations, resulting in the chromosome-scale phasing of subsequent mutations. We characterize this process in mutagen-induced mouse liver tumours and show that DNA replication across persisting lesions can produce multiple alternative alleles in successive cell divisions, thereby generating both multiallelic and combinatorial genetic diversity. The phasing of lesions enables accurate measurement of strand-biased repair processes, quantification of oncogenic selection and fine mapping of sister-chromatid-exchange events. Finally, we demonstrate that lesion segregation is a unifying property of exogenous mutagens, including UV light and chemotherapy agents in human cells and tumours, which has profound implications for the evolution and adaptation of cancer genomes.

Associations Between End-Tidal Carbon Dioxide During Pediatric Cardiopulmonary Resuscitation, Cardiopulmonary Resuscitation Quality, and Survival.

BACKGROUND: Supported by laboratory and clinical investigations of adult cardiopulmonary arrest, resuscitation guidelines recommend monitoring end-tidal carbon dioxide (ETCO2) as an indicator of cardiopulmonary resuscitation (CPR) quality, but they note that "specific values to guide therapy have not been established in children." METHODS: This prospective observational cohort study was a National Heart, Lung, and Blood Institute-funded ancillary study of children in the ICU-RESUS trial (Intensive Care Unit-Resuscitation Project; NCT02837497). Hospitalized children (≤18 years of age and ≥37 weeks postgestational age) who received chest compressions of any duration for cardiopulmonary arrest, had an endotracheal or tracheostomy tube at the start of CPR, and evaluable intra-arrest ETCO2 data were included. The primary exposure was event-level average ETCO2 during the first 10 minutes of CPR (dichotomized as ≥20 mm Hg versus <20 mm Hg on the basis of adult literature). The primary outcome was survival to hospital discharge. Secondary outcomes were sustained return of spontaneous circulation, survival to discharge with favorable neurological outcome, and new morbidity among survivors. Poisson regression measured associations between ETCO2 and outcomes as well as the association between ETCO2 and other CPR characteristics: (1) invasively measured systolic and diastolic blood pressures, and (2) CPR quality and chest compression mechanics metrics (ie, time to CPR start; chest compression rate, depth, and fraction; ventilation rate). RESULTS: Among 234 included patients, 133 (57%) had an event-level average ETCO2 ≥20 mm Hg. After controlling for a priori covariates, average ETCO2 ≥20 mm Hg was associated with a higher incidence of survival to hospital discharge (86/133 [65%] versus 48/101 [48%]; adjusted relative risk, 1.33 [95% CI, 1.04-1.69]; P=0.023) and return of spontaneous circulation (95/133 [71%] versus 59/101 [58%]; adjusted relative risk, 1.22 [95% CI, 1.00-1.49]; P=0.046) compared with lower values. ETCO2 ≥20 mm Hg was not associated with survival with favorable neurological outcome or new morbidity among survivors. Average 2 ≥20 mm Hg was associated with higher systolic and diastolic blood pressures during CPR, lower CPR ventilation rates, and briefer pre-CPR arrest durations compared with lower values. Chest compression rate, depth, and fraction did not differ between ETCO2 groups. CONCLUSIONS: In this multicenter study of children with in-hospital cardiopulmonary arrest, ETCO2 ≥20 mm Hg was associated with better outcomes and higher intra-arrest blood pressures, but not with chest compression quality metrics.

Why marginal CO2 emissions are not decreasing for US electricity: Estimates and implications for climate policy.

Marginal emissions of CO2 from the electricity sector are critical for evaluating climate policies that rely on shifts in electricity demand or supply. This paper provides estimates of marginal CO2 emissions from US electricity generation using the most recently available and comprehensive data. The estimates vary by region, hour of the day, and year to year over the last decade. We identify an important and somewhat counterintuitive finding: While average emissions have decreased substantially over the last decade (28% nationally), marginal emissions have increased (7% nationally). We show that underlying these trends is primarily a shift toward greater reliance on coal to satisfy marginal electricity use. We apply our estimates to an analysis of the Biden administration's target of having electric vehicles (EVs) make up 50% of new vehicle purchases by 2030. We find that, without significant and concurrent changes to the electricity sector, the increase in electricity emissions is likely to offset more than half of the emission reductions from having fewer gasoline-powered vehicles on the road. Moreover, using average rather than marginal emissions to predict the impacts significantly overestimates the emission benefits. Overall, we find that the promise of EVs for reducing emissions depends, to a large degree, on complementary policies that decarbonize both average and marginal emissions in the electricity sector.

The changing landscape of text mining: a review of approaches for ecology and evolution.

In ecology and evolutionary biology, the synthesis and modelling of data from published literature are commonly used to generate insights and test theories across systems. However, the tasks of searching, screening, and extracting data from literature are often arduous. Researchers may manually process hundreds to thousands of articles for systematic reviews, meta-analyses, and compiling synthetic datasets. As relevant articles expand to tens or hundreds of thousands, computer-based approaches can increase the efficiency, transparency and reproducibility of literature-based research. Methods available for text mining are rapidly changing owing to developments in machine learning-based language models. We review the growing landscape of approaches, mapping them onto three broad paradigms (frequency-based approaches, traditional Natural Language Processing and deep learning-based language models). This serves as an entry point to learn foundational and cutting-edge concepts, vocabularies, and methods to foster integration of these tools into ecological and evolutionary research. We cover approaches for modelling ecological texts, generating training data, developing custom models and interacting with large language models and discuss challenges and possible solutions to implementing these methods in ecology and evolution.

Healthy dynamics of CD4 T cells may drive HIV resurgence in perinatally-infected infants on antiretroviral therapy.

In 2019 there were 490,000 children under five living with HIV. Understanding the dynamics of HIV suppression and rebound in this age group is crucial to optimizing treatment strategies and increasing the likelihood of infants achieving and sustaining viral suppression. Here we studied data from a cohort of 122 perinatally-infected infants who initiated antiretroviral treatment (ART) early after birth and were followed for up to four years. These data included longitudinal measurements of viral load (VL) and CD4 T cell numbers, together with information regarding treatment adherence. We previously showed that the dynamics of HIV decline in 53 of these infants who suppressed VL within one year were similar to those in adults. However, in extending our analysis to all 122 infants, we find that a deterministic model of HIV infection in adults cannot explain the full diversity in infant trajectories. We therefore adapt this model to include imperfect ART adherence and natural CD4 T cell decline and reconstitution processes in infants. We find that individual variation in both processes must be included to obtain the best fits. We also find that infants with faster rates of CD4 reconstitution on ART were more likely to experience resurgences in VL. Overall, our findings highlight the importance of combining mathematical modeling with clinical data to disentangle the role of natural immune processes and viral dynamics during HIV infection.

Potential safety implications of fatty acid-binding protein inhibition.

Fatty acid-binding proteins (FABPs) are small intracellular proteins that regulate fatty acid metabolism, transport, and signalling. There are ten known human isoforms, many of which are upregulated and involved in clinical pathologies. As such, FABP inhibition may be beneficial in disease states such as cancer, and those involving the cardiovascular system, metabolism, immunity, and cognition. Recently, a potent, selective FABP5 inhibitor (ART26.12), with 90-fold selectivity to FABP3 and 20-fold selectivity to FABP7, was found to be remarkably benign, with a no-observed-adverse-effect level of 1000 mg/kg in rats and dogs, showing no genotoxicity, cardiovascular, central, or respiratory toxicity. To understand the potential implication of FABP inhibition more fully, this review systematically assessed literature investigating genetic knockout, knockdown, and pharmacological inhibition of FABP3, FABP4, FABP5, or FABP7. Analysis of the literature revealed that animals bred not to express FABPs showed the most biological effects, suggesting key roles of these proteins during development. FABP ablation sometimes exacerbated symptoms of disease models, particularly those linked to metabolism, inflammatory and immune responses, cardiac contractility, neurogenesis, and cognition. However, FABP inhibition (genetic silencing or pharmacological) had a positive effect in many more disease conditions. Several polymorphisms of each FABP gene have also been linked to pathological conditions, but it was unclear how several polymorphisms affected protein function. Overall, analysis of the literature to date suggests that pharmacological inhibition of FABPs in adults is of low risk.

Resuscitation arterial waveform quantification and outcomes in pediatric bidirectional Glenn and Fontan patients.

BACKGROUND: Resuscitation with chest compressions and positive pressure ventilation in Bidirectional Glenn (BDG) or Fontan physiology may compromise passive venous return and accentuate neurologic injury. We hypothesized that arterial pressure and survival would be better in BDG than Fontan patients. METHODS: Secondary analyses of the Pediatric Intensive Care Quality of CPR and Improving Outcomes from Pediatric Cardiac Arrest databases. P-values were considered significant if < 0.05. RESULTS: In total, 64 patients had either BDG (42/64, 66%) or Fontan (22/64, 34%) anatomy. Return of spontaneous circulation was achieved in 76% of BDG patients versus 59% of Fontan patients and survival with favorable neurologic outcome in 22/42 (52%) BDG versus 6/22 (27%) Fontan patients, p = 0.067. Twelve of 24 (50%) BDG and 2/7 (29%) Fontan patients who survived to discharge suffered new morbidity as defined by worsening Functional Status Score. More BDG patients achieved adequate DBP (≥25 mmHg for neonates and infants; ≥ 30 mmHg for children) than Fontan patients (21/23 (91%) vs. 5/11 (46%), p = 0.007). CONCLUSIONS: Only 27% of Fontan patients survived to hospital discharge with favorable neurologic outcome after CPR, likely driven by inadequate diastolic blood pressure during resuscitation. One half of the BDG patients who survived to hospital discharge had new neurologic morbidity. BACKGROUND: Cardiac arrest in patients with congenital heart disease (CHD) may present challenges to resuscitation based on the unique cardiovascular physiology resulting from surgical palliation. Recent resuscitation guidelines for CHD patients highlight the lack of data surrounding these special patient populations.1 Univentricular heart disease is palliated by a series of cardiac surgeries that stepwise result in passive pulmonary perfusion from the systemic venous system directly to the pulmonary vascular bed. The bidirectional Glenn (BDG) palliation directly anastomoses the superior vena cava (SVC) to the pulmonary arterial system and leaves normal inferior vena cava (IVC) venous return to the heart.2 The Fontan palliation baffles IVC flow directly to the pulmonary vascular bed which relieves cyanosis due to right to left shunting, but requires systemic ventricular preload to be directly dependent upon pulmonary vascular resistance and intrathoracic pressures.3 IMPACT STATEMENT: Hemodynamic waveforms from 2 large prospective observational studies now allow for exploration of physiology during cardiopulmonary resuscitation for unique anatomy associated with single ventricle congenital heart disease. Fewer patients with Fontan physiology (46%) achieved an adequate diastolic blood pressure (defined as ≥ 25 mmHg for neonates and infants and ≥ 30 mmHg for children) than bidirectional Glenn patients during cardiopulmonary resuscitation (91%, p = 0.007). Only 27% of Fontan patients survived to hospital discharge with favorable neurologic outcome after cardiopulmonary resuscitation. Of the bidirectional Glenn patients who survived, 50% developed a new morbidity as quantified by the Functional Status Score.

Validating the safety of low-dose CTPA in pregnancy: results from the OPTICA (Optimised CT Pulmonary Angiography in Pregnancy) Study.

BACKGROUND: Pulmonary embolism (PE) is a leading cause of pregnancy-related mortality. CT pulmonary angiogram (CTPA) is the first-line advanced imaging modality for suspected PE in pregnancy at institutes offering low-dose techniques; however, a protocol balancing safety with low dose remains undefined. The wide range of CTPA doses reported in pregnancy suggests a lack of confidence in implementing low-dose techniques in this group. PURPOSE: To define and validate the safety, radiation dose and image quality of a low-dose CTPA protocol optimised for pregnancy. MATERIALS AND METHODS: The OPTICA study is a prospective observational study. Pregnant study participants with suspected PE underwent the same CTPA protocol between May 2018 and February 2022. The primary outcome, CTPA safety, was judged by the reference standard; the 3-month incidence of venous thromboembolism (VTE) in study participants with a negative index CTPA. Secondary outcomes defined radiation dose and image quality. Absorbed breast, maternal effective and fetal doses were estimated by Monte-Carlo simulation on gestation-matched phantoms. Image quality was assessed by signal-to-noise and contrast-to-noise ratios and a Likert score for pulmonary arterial enhancement. RESULTS: A total of 116 CTPAs were performed in 113 pregnant women of which 16 CTPAs were excluded. PE was diagnosed on 1 CTPA and out-ruled in 99. The incidence of recurrent symptomatic VTE was 0.0% (one-sided 95% CI, 2.66%) at follow-up. The mean absorbed breast dose was 2.9 ± 2.1mGy, uterine/fetal dose was 0.1 ± 0.2mGy and maternal effective dose was 1.4 ± 0.9mSv. Signal-to-noise ratio (SNR) was 11.9 ± 3.7. Contrast-to-noise ratio (CNR) was 10.4 ± 3.5. CONCLUSION: The OPTICA CTPA protocol safely excluded PE in pregnant women across all trimesters, with low fetal and maternal radiation. CLINICAL RELEVANCE: OPTICA (Optimised CT Pulmonary Angiography in Pregnancy) is the first prospective study to define the achievable radiation dose, image-quality and safety of a low-dose CT pulmonary angiogram protocol optimised for pregnancy (NCT04179487). It provides the current benchmark for safe and achievable CT pulmonary angiogram doses in the pregnant population. KEY POINTS: • Despite the increased use of CT pulmonary angiogram in pregnancy, an optimised low-dose protocol has not been defined and reported doses in pregnancy continue to vary widely. • The OPTICA (Optimised CT Pulmonary Angiography in Pregnancy) study prospectively defines the achievable dose, image quality and safety of a low-dose CT pulmonary angiogram protocol using widely available technology. • OPTICA provides a benchmark for safe and achievable CT pulmonary angiogram doses in the pregnant population.

Early bolus epinephrine administration during pediatric cardiopulmonary resuscitation for bradycardia with poor perfusion: an ICU-resuscitation study.

BACKGROUND: Half of pediatric in-hospital cardiopulmonary resuscitation (CPR) events have an initial rhythm of non-pulseless bradycardia with poor perfusion. Our study objectives were to leverage granular data from the ICU-RESUScitation (ICU-RESUS) trial to: (1) determine the association of early epinephrine administration with survival outcomes in children receiving CPR for bradycardia with poor perfusion; and (2) describe the incidence and time course of the development of pulselessness. METHODS: Prespecified secondary analysis of ICU-RESUS, a multicenter cluster randomized trial of children (< 19 years) receiving CPR in 18 intensive care units in the United States. Index events (October 2016-March 2021) lasting ≥ 2 min with a documented initial rhythm of bradycardia with poor perfusion were included. Associations between early epinephrine (first 2 min of CPR) and outcomes were evaluated with Poisson multivariable regression controlling for a priori pre-arrest characteristics. Among patients with arterial lines, intra-arrest blood pressure waveforms were reviewed to determine presence of a pulse during CPR interruptions. The temporal nature of progression to pulselessness was described and outcomes were compared between patients according to subsequent pulselessness status. RESULTS: Of 452 eligible subjects, 322 (71%) received early epinephrine. The early epinephrine group had higher pre-arrest severity of illness and vasoactive-inotrope scores. Early epinephrine was not associated with survival to discharge (aRR 0.97, 95%CI 0.82, 1.14) or survival with favorable neurologic outcome (aRR 0.99, 95%CI 0.82, 1.18). Among 186 patients with invasive blood pressure waveforms, 118 (63%) had at least 1 period of pulselessness during the first 10 min of CPR; 86 (46%) by 2 min and 100 (54%) by 3 min. Sustained return of spontaneous circulation was highest after bradycardia with poor perfusion (84%) compared to bradycardia with poor perfusion progressing to pulselessness (43%) and bradycardia with poor perfusion progressing to pulselessness followed by return to bradycardia with poor perfusion (62%) (p < 0.001). CONCLUSIONS: In this cohort of pediatric CPR events with an initial rhythm of bradycardia with poor perfusion, we failed to identify an association between early bolus epinephrine and outcomes when controlling for illness severity. Most children receiving CPR for bradycardia with poor perfusion developed subsequent pulselessness, 46% within 2 min of CPR onset.

Brief report: incidence and outcomes of pediatric tracheal intubation-associated cardiac arrests in the ICU-RESUS clinical trial.

BACKGROUND: Tracheal intubation (TI)-associated cardiac arrest (TI-CA) occurs in 1.7% of pediatric ICU TIs. Our objective was to evaluate resuscitation characteristics and outcomes between cardiac arrest patients with and without TI-CA. METHODS: Secondary analysis of cardiac arrest patients in both ICU-RESUS trial and ancillary CPR-NOVA study. The primary exposure was TI-CA, defined as cardiac arrest occurred during TI procedure or within 20 min after endotracheal tube placement. The primary outcome was survival to hospital discharge with favorable neurological outcome (Pediatric Cerebral Performance Category score 1-3 or unchanged). RESULTS: Among 315 children with cardiac arrests, 48 (15.2%) met criteria for TI-CA. Pre-existing medical conditions were similar between groups. Pre-arrest non-invasive mechanical ventilation was more common among TI-CA patients (18/48, 37.5%) compared to non-TI-CA patients (35/267, 13.1%). In 48% (23/48), the TI-CA occurred within 20 min after intubation (i.e., not during intubation). Duration of CPR was longer in TI-CA patients (median 11.0 min, interquartile range [IQR]: 2.5, 35.5) than non-TI-CA patients (median 5.0 min, IQR 2.0, 21.0), p = 0.03. Return of spontaneous circulation occurred in 32/48 (66.7%) TI-CA versus 186/267 (69.7%) non-TI-CA, p = 0.73. Survival to hospital discharge with favorable neurological outcome occurred in 29/48 (60.4%) TI-CA versus 146/267 (54.7%) non-TI-CA, p = 0.53. CONCLUSIONS: Fifteen percent of these pediatric ICU cardiac arrests were associated with TI. Half of TI-CA occurred after endotracheal tube placement. While duration of CPR was longer in TI-CA patients, there were no differences in unadjusted outcomes following TI-CA versus non-TI-CA. TRIAL REGISTRATION: The ICU-RESUS (ClinicalTrials.gov Identifier: NCT02837497).

Urinary biomarkers associated with acute kidney injury in pediatric mechanical circulatory support patients.

BACKGROUND: In patients requiring mechanical circulatory support (MCS), the incidence of acute kidney injury (AKI) is between 37 and 63%. In this study, we performed an exploratory analysis evaluating the relationship of multiple urine biomarkers with AKI development in pediatric MCS patients. METHODS: This is a single center retrospective study in a pediatric cohort receiving MCS from August 2014 to November 2020. We measured 14 urine biomarkers of kidney injury on day 1 following MCS initiation and analyzed their association with development of AKI in the first 7 days of MCS initiation. RESULTS: Sixty patients met inclusion criteria. Patients with AKI were more likely to be supported by venoarterial extracorporeal membrane oxygenation (65% vs. 8.3%, p < 0.001), compared to the no AKI group and less likely to have ventricular assist devices (10% vs. 50%, p < 0.001). There was a significant increase in the median urine albumin and urine osteoactivin in the AKI group, compared to the no AKI group (p = 0.020 and p = 0.018, respectively). When normalized to urine creatinine (UCr), an increased log osteoactivin/UCr was associated with higher odds of AKI development (OR: 2.05; 95% CI: 1.07, 4.44; p = 0.028), and higher log epidermal growth factor (EGF)/UCr (OR: 0.41; 95% CI: 0.15, 0.96) was associated with decreased odds of AKI. CONCLUSIONS: Early increase in urine osteoactivin is associated with AKI development within 7 days of MCS initiation in pediatric patients. Contrary, an increased urine EGF is associated with kidney protection. A higher resolution version of the Graphical abstract is available as Supplementary information.

Management of Extracorporeal Membrane Oxygenation Anticoagulation in the Perioperative Period: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference.

OBJECTIVES: To derive systematic review-informed, modified Delphi consensus regarding the management of children on extracorporeal membrane oxygenation (ECMO) undergoing invasive procedures or interventions developed by the Pediatric Anticoagulation on ECMO CollaborativE (PEACE) Consensus Conference. DATA SOURCES: A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021. STUDY SELECTION: ECMO anticoagulation and hemostasis management in the perioperative period and during procedures. DATA EXTRACTION: Two authors reviewed all citations independently, with a third independent reviewer resolving any conflicts. Seventeen references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form. DATA SYNTHESIS: Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements for the management of bleeding and thrombotic complications in pediatric ECMO patients. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. Four good practice statements, 7 recommendations, and 18 consensus statements are presented. CONCLUSIONS: Although agreement among experts was strong, important future research is required in this population for evidence-informed recommendations.

Clinical Outcomes After Tracheostomy in Children With Single Ventricle Physiology: Collaborative Research From the Pediatric Cardiac Intensive Care Society Multicenter Cohort, 2010-2021.

OBJECTIVES: Multicenter studies reporting outcomes following tracheostomy in children with congenital heart disease are limited, particularly in patients with single ventricle physiology. We aimed to describe clinical characteristics and outcomes in a multicenter cohort of patients with single ventricle physiology who underwent tracheostomy before Fontan operation. DESIGN: Multicenter retrospective cohort study. SETTING: Twenty-one tertiary care pediatric institutions participating in the Collaborative Research from the Pediatric Cardiac Intensive Care Society. PATIENTS: We reviewed 99 children with single ventricle physiology who underwent tracheostomy before the Fontan operation at 21 institutions participating in Collaborative Research from the Pediatric Cardiac Intensive Care Society between January 2010 and December 2020, with follow-up through December 31, 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Death occurred in 51 of 99 patients (52%). Cox proportional hazard analysis was performed to determine factors associated with death after tracheostomy. Results are presented as hazard ratio (HR) with 95% CIs. Nonrespiratory indication(s) for tracheostomy (HR, 2.21; 95% CI, 1.14-4.32) and number of weeks receiving mechanical ventilation before tracheostomy (HR, 1.06; 95% CI, 1.02-1.11) were independently associated with greater hazard of death. In contrast, diagnosis of tricuspid atresia or Ebstein's anomaly was associated with less hazard of death (HR, 0.16; 95% CI, 0.04-0.69). Favorable outcome, defined as survival to Fontan operation or decannulation while awaiting Fontan operation with viable cardiopulmonary physiology, occurred in 29 of 99 patients (29%). Median duration of mechanical ventilation before tracheostomy was shorter in patients who survived to favorable outcome (6.1 vs. 12.1 wk; p < 0.001), and only one of 16 patients with neurologic indications for tracheostomy and 0 of ten patients with cardiac indications for tracheostomy survived to favorable outcome. CONCLUSIONS: For children with single ventricle physiology who undergo tracheostomy, mortality risk is high and should be carefully considered when discussing tracheostomy as an option for these children. Favorable outcomes are possible, although thoughtful attention to patient selection and tracheostomy timing are likely necessary to achieve this goal.

Survival With Favorable Neurologic Outcome and Quality of Cardiopulmonary Resuscitation Following In-Hospital Cardiac Arrest in Children With Cardiac Disease Compared With Noncardiac Disease.

OBJECTIVES: To assess associations between outcome and cardiopulmonary resuscitation (CPR) quality for in-hospital cardiac arrest (IHCA) in children with medical cardiac, surgical cardiac, or noncardiac disease. DESIGN: Secondary analysis of a multicenter cluster randomized trial, the ICU-RESUScitation Project (NCT02837497, 2016-2021). SETTING: Eighteen PICUs. PATIENTS: Children less than or equal to 18 years old and greater than or equal to 37 weeks postconceptual age receiving chest compressions (CC) of any duration during the study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 1,100 children with IHCA, there were 273 medical cardiac (25%), 383 surgical cardiac (35%), and 444 noncardiac (40%) cases. Favorable neurologic outcome was defined as no more than moderate disability or no worsening from baseline Pediatric Cerebral Performance Category at discharge. The medical cardiac group had lower odds of survival with favorable neurologic outcomes compared with the noncardiac group (48% vs 55%; adjusted odds ratio [aOR] [95% CI], aOR 0.59 [95% CI, 0.39-0.87], p = 0.008) and surgical cardiac group (48% vs 58%; aOR 0.64 [95% CI, 0.45-0.9], p = 0.01). We failed to identify a difference in favorable outcomes between surgical cardiac and noncardiac groups. We also failed to identify differences in CC rate, CC fraction, ventilation rate, intra-arrest average target diastolic or systolic blood pressure between medical cardiac versus noncardiac, and surgical cardiac versus noncardiac groups. The surgical cardiac group had lower odds of achieving target CC depth compared to the noncardiac group (OR 0.15 [95% CI, 0.02-0.52], p = 0.001). We failed to identify a difference in the percentage of patients achieving target CC depth when comparing medical cardiac versus noncardiac groups. CONCLUSIONS: In pediatric IHCA, medical cardiac patients had lower odds of survival with favorable neurologic outcomes compared with noncardiac and surgical cardiac patients. We failed to find differences in CPR quality between medical cardiac and noncardiac patients, but there were lower odds of achieving target CC depth in surgical cardiac compared to noncardiac patients.

Early Cardiac Arrest Hemodynamics, End-Tidal C o2 , and Outcome in Pediatric Extracorporeal Cardiopulmonary Resuscitation: Secondary Analysis of the ICU-RESUScitation Project Dataset (2016-2021).

OBJECTIVES: Cannulation for extracorporeal membrane oxygenation during active extracorporeal cardiopulmonary resuscitation (ECPR) is a method to rescue patients refractory to standard resuscitation. We hypothesized that early arrest hemodynamics and end-tidal C o2 (ET co2 ) are associated with survival to hospital discharge with favorable neurologic outcome in pediatric ECPR patients. DESIGN: Preplanned, secondary analysis of pediatric Utstein, hemodynamic, and ventilatory data in ECPR patients collected during the 2016-2021 Improving Outcomes from Pediatric Cardiac Arrest study; the ICU-RESUScitation Project (ICU-RESUS; NCT02837497). SETTING: Eighteen ICUs participated in ICU-RESUS. PATIENTS: There were 97 ECPR patients with hemodynamic waveforms during cardiopulmonary resuscitation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Overall, 71 of 97 patients (73%) were younger than 1 year old, 82 of 97 (85%) had congenital heart disease, and 62 of 97 (64%) were postoperative cardiac surgical patients. Forty of 97 patients (41%) survived with favorable neurologic outcome. We failed to find differences in diastolic or systolic blood pressure, proportion achieving age-based target diastolic or systolic blood pressure, or chest compression rate during the initial 10 minutes of CPR between patients who survived with favorable neurologic outcome and those who did not. Thirty-five patients had ET co2 data; of 17 survivors with favorable neurologic outcome, four of 17 (24%) had an average ET co2 less than 10 mm Hg and two (12%) had a maximum ET co2 less than 10 mm Hg during the initial 10 minutes of resuscitation. CONCLUSIONS: We did not identify an association between early hemodynamics achieved by high-quality CPR and survival to hospital discharge with favorable neurologic outcome after pediatric ECPR. Candidates for ECPR with ET co2 less than 10 mm Hg may survive with favorable neurologic outcome.

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.