The enteroendocrine axis and its effect on gastrointestinal function, nutrition, and inflammation.

PURPOSE OF REVIEW: Gastrointestinal (GI) dysfunction limits enteral nutrition (EN) delivery in critical illness and contributes to systemic inflammation. The enteroendocrine (EE) axis plays an integral role in this interface between nutrition, inflammation, and GI function in critical illness. In this review, we present an overview of the EE system with a focus on its role in GI inflammation and function. RECENT FINDINGS: Enteroendocrine cells have been primarily described in their role in macronutrient digestion and absorption. Recent research has expanded on the diverse functions of EE cells including their ability to sense microbial peptides and metabolites and regulate immune function and inflammation. Therefore, EE cells may be both affected by and contribute to many pathophysiologic states and interventions of critical illness such as dysbiosis, inflammation, and alternative EN strategies. In this review, we present an overview of EE cells including their growing role in nonnutrient functions and integrate this understanding into relevant aspects of critical illness with a focus on EN. SUMMARY: The EE system is key in maintaining GI homeostasis in critical illness, and how it is impacted and contributes to outcomes in the setting of dysbiosis, inflammation and different feeding strategies in critical illness should be considered.

Automated Calculator for the Pediatric Sequential Organ Failure Assessment Score: Development and External Validation in a Single-Center 7-Year Cohort, 2015-2021.

OBJECTIVES: The pediatric Sequential Organ Failure Assessment (pSOFA) score summarizes severity of organ dysfunction and can be used to predict in-hospital mortality. Manual calculation of the pSOFA score is time-consuming and prone to human error. An automated method that is open-source, flexible, and scalable for calculating the pSOFA score directly from electronic health record data is desirable. DESIGN: Single-center, retrospective cohort study. SETTING: Quaternary 40-bed PICU. PATIENTS: All patients admitted to the PICU between 2015 and 2021 with ICU stay of at least 24 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We used 77 records to evaluate the automated score. The automated algorithm had an overall accuracy of 97%. The algorithm calculated the respiratory component of two cases incorrectly. An expert human annotator had an initial accuracy of 75% at the patient level and 95% at the component level. An untrained human annotator with general clinical research experience had an overall accuracy of 16% and component-wise accuracy of 67%. Weighted kappa for agreement between the automated method and the expert annotator's initial score was 0.92 (95% CI, 0.88-0.95), and between the untrained human annotator and the automated score was 0.50 (95% CI, 0.36-0.61). Data from 9146 patients (in-hospital mortality 3.6%) were included to validate externally the discriminability of the automated pSOFA score. The admission-day pSOFA score had an area under the receiver operating characteristic curve of 0.79 (95% CI, 0.77-0.82). CONCLUSIONS: The developed automated algorithm calculates pSOFA score with high accuracy and is more accurate than a trained expert rater and nontrained data abstracter. pSOFA's performance for predicting in-hospital mortality was lower in our cohort than it was for the originally derived score.

Dynamic Prediction of Mortality Using Longitudinally Measured Pediatric Sequential Organ Failure Assessment Scores: A Joint Modeling Approach.

OBJECTIVES: The pediatric Sequential Organ Failure Assessment (pSOFA) score was designed to track illness severity and predict mortality in critically ill children. Most commonly, pSOFA at a point in time is used to assess a static patient condition. However, this approach has a significant drawback because it fails to consider any changes in a patients' condition during their PICU stay and, especially, their response to initial critical care treatment. We aimed to evaluate the performance of longitudinal pSOFA scores for predicting mortality. DESIGN: Single-center, retrospective cohort study. SETTING: Quaternary 40-bed PICU. PATIENTS: All patients admitted to the PICU between 2015 and 2021 with at least 24 hours of ICU stay. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We calculated daily pSOFA scores up to 30 days, or until death or discharge from the PICU, if earlier. We used the joint longitudinal and time-to-event data model for the dynamic prediction of 30-day in-hospital mortality. The dataset, which included 9146 patients with a 30-day in-hospital mortality of 2.6%, was divided randomly into training (75%) and validation (25%) subsets, and subjected to 40 repeated stratified cross-validations. We used dynamic area under the curve (AUC) to evaluate the discriminative performance of the model. Compared with the admission-day pSOFA score, AUC for predicting mortality between days 5 and 30 was improved on average by 6.4% (95% CI, 6.3-6.6%) using longitudinal pSOFA scores from the first 3 days and 9.2% (95% CI, 9.0-9.5%) using scores from the first 5 days. CONCLUSIONS: Compared with admission-day pSOFA score, longitudinal pSOFA scores improved the accuracy of mortality prediction in PICU patients at a single center. The pSOFA score has the potential to be used dynamically for the evaluation of patient conditions.

Comparing the Quality of Domain-Specific Versus General Language Models for Artificial Intelligence-Generated Differential Diagnoses in PICU Patients.

OBJECTIVES: Generative language models (LMs) are being evaluated in a variety of tasks in healthcare, but pediatric critical care studies are scant. Our objective was to evaluate the utility of generative LMs in the pediatric critical care setting and to determine whether domain-adapted LMs can outperform much larger general-domain LMs in generating a differential diagnosis from the admission notes of PICU patients. DESIGN: Single-center retrospective cohort study. SETTING: Quaternary 40-bed PICU. PATIENTS: Notes from all patients admitted to the PICU between January 2012 and April 2023 were used for model development. One hundred thirty randomly selected admission notes were used for evaluation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Five experts in critical care used a 5-point Likert scale to independently evaluate the overall quality of differential diagnoses: 1) written by the clinician in the original notes, 2) generated by two general LMs (BioGPT-Large and LLaMa-65B), and 3) generated by two fine-tuned models (fine-tuned BioGPT-Large and fine-tuned LLaMa-7B). Differences among differential diagnoses were compared using mixed methods regression models. We used 1,916,538 notes from 32,454 unique patients for model development and validation. The mean quality scores of the differential diagnoses generated by the clinicians and fine-tuned LLaMa-7B, the best-performing LM, were 3.43 and 2.88, respectively (absolute difference 0.54 units [95% CI, 0.37-0.72], p < 0.001). Fine-tuned LLaMa-7B performed better than LLaMa-65B (absolute difference 0.23 unit [95% CI, 0.06-0.41], p = 0.009) and BioGPT-Large (absolute difference 0.86 unit [95% CI, 0.69-1.0], p < 0.001). The differential diagnosis generated by clinicians and fine-tuned LLaMa-7B were ranked as the highest quality in 144 (55%) and 74 cases (29%), respectively. CONCLUSIONS: A smaller LM fine-tuned using notes of PICU patients outperformed much larger models trained on general-domain data. Currently, LMs remain inferior but may serve as an adjunct to human clinicians in real-world tasks using real-world data.

Stress Ulcer Prophylaxis Versus Placebo-A Blinded Pilot Randomized Controlled Trial to Evaluate the Safety of Two Strategies in Critically Ill Infants With Congenital Heart Disease.

OBJECTIVES: The routine use of stress ulcer prophylaxis (SUP) in infants with congenital heart disease (CHD) in the cardiac ICU (CICU) is controversial. We aimed to conduct a pilot study to explore the feasibility of performing a subsequent larger trial to assess the safety and efficacy of withholding SUP in this population (NCT03667703). DESIGN, SETTING, PATIENTS: Single-center, prospective, double-blinded, parallel group (SUP vs. placebo), pilot randomized controlled pilot trial (RCT) in infants with CHD admitted to the CICU and anticipated to require respiratory support for greater than 24 hours. INTERVENTIONS: Patients were randomized 1:1 (stratified by age and admission type) to receive a histamine-2 receptor antagonist or placebo until respiratory support was discontinued, up to 14 days, or transfer from the CICU, if earlier. MEASUREMENTS AND MAIN RESULTS: Feasibility was defined a priori by thresholds of screening rate, consent rate, timely drug allocation, and protocol adherence. The safety outcome was the rate of clinically significant upper gastrointestinal (UGI) bleeding. We screened 1,426 patients from February 2019 to March 2022; of 132 eligible patients, we gained informed consent in 70 (53%). Two patients did not require CICU admission after obtaining consent, and the remaining 68 patients were randomized to SUP (n = 34) or placebo (n = 34). Ten patients were withdrawn early, because of a change in eligibility (n = 3) or open-label SUP use (n = 7, 10%). Study procedures were completed in 58 patients (89% protocol adherence). All feasibility criteria were met. There were no clinically significant episodes of UGI bleeding during the pilot RCT. The percentage of patients with other nonserious adverse events did not differ between groups. CONCLUSIONS: Withholding of SUP in infants with CHD admitted to the CICU was feasible. A larger multicenter RCT designed to confirm the safety of this intervention and its impact on incidence of UGI bleeding, gastrointestinal microbiome, and other clinical outcomes is warranted.

Validation and Extension of the Association Between Potentially Excess Oxygen Exposure and Death in Mechanically Ventilated Children.

OBJECTIVES: "Cumulative excess oxygen exposure" (CEOE)-previously defined as the mean hourly administered Fio2 above 0.21 when the corresponding hourly Spo2 was 95% or above-was previously shown to be associated with mortality. The objective of this study was to examine the relationship among Fio2, Spo2, and mortality in an independent cohort of mechanically ventilated children. DESIGN: Retrospective cross-sectional study. SETTING: Quaternary-care PICU. PATIENTS: All patients admitted to the PICU between 2012 and 2021 and mechanically ventilated via endotracheal tube for at least 24 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among 3,354 patients, 260 (8%) died. Higher CEOE quartile was associated with increased mortality (p = 0.001). The highest CEOE quartile had an 87% increased risk of mortality (95% CI, 7-236) compared with the first CEOE quartile. The hazard ratio for extended CEOE exposure, which included mechanical ventilation data from throughout the patients' mechanical ventilation time rather than only from the first 24 hours of mechanical ventilation, was 1.03 (95% CI, 1.02-1.03). CONCLUSIONS: Potentially excess oxygen exposure in patients whose oxygen saturation was at least 95% was associated with increased mortality.

Long-Term Functional Outcomes at 1-Year After Hospital Discharge in Critically Ill Neonates With Congenital Diaphragmatic Hernia.

OBJECTIVES: Congenital diaphragmatic hernia (CDH) is a birth defect associated with long-term morbidity. Our objective was to examine longitudinal change in Functional Status Scale (FSS) after hospital discharge in CDH survivors. DESIGN: Single-center retrospective cohort study. SETTING: Center for comprehensive CDH management at a quaternary, free-standing children's hospital. PATIENTS: Infants with Bochdalek CDH were admitted to the ICU between January 2009 and December 2019 and survived until hospital discharge. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred forty-two infants (58% male, mean birth weight 3.08 kg, 80% left-sided defects) met inclusion criteria. Relevant clinical data were extracted from the medical record to calculate FSS (primary outcome) at hospital discharge and three subsequent outpatient follow-up time points. The median (interquartile range [IQR]) FSS score at hospital discharge was 8.0 (7.0-9.0); 39 patients (27.5%) had at least moderate impairment (FSS ≥ 9). Median (IQR) FSS at 0- to 6-month ( n = 141), 6- to 12-month ( n = 141), and over 12-month ( n = 140) follow-up visits were 7.0 (7.0-8.0), 7.0 (6.0-8.0), and 6.0 (6.0-7.0), respectively. Twenty-one patients (15%) had at least moderate impairment at over 12-month follow-up; median composite FSS scores in the over 12-month time point decreased by 2.0 points from hospital discharge. Median feeding domain scores improved by 1.0 (1.0-2.0), whereas other domain scores remained without impairment. Multivariable analysis demonstrated right-sided, C- or D-size defects, extracorporeal membrane oxygenation use, cardiopulmonary resuscitation, and chromosomal anomalies were associated with impairment. CONCLUSIONS: The majority of CDH survivors at our center had mild functional status impairment (FSS ≤ 8) at discharge and 1-year follow-up; however, nearly 15% of patients had moderate impairment during this time period. The feeding domain had the highest level of functional impairment. We observed unchanged or improving functional status longitudinally over 1-year follow-up after hospital discharge. Longitudinal outcomes will guide interdisciplinary management strategies in CDH survivors.

Quality measurement and surveillance platforms in critically ill children: A scoping review.

BACKGROUND/AIM: The objective of this study was to describe current surveillance platforms which support routine quality measurement in paediatric critical care. METHOD: Scoping review. The search strategy consisted of a traditional database and grey literature search as well as expert consultation. Surveillance platforms were eligible for inclusion if they collected measures of quality in critically ill children. RESULTS: The search strategy identified 21 surveillance platforms, collecting 57 unique outcome (70%), process (23%), and structural (7%) quality measures. Hospital-associated infections were the most commonly collected outcome measure across all platforms (n = 11; 52%). In general, case definitions were not harmonised across platforms, with the exception of nationally mandated hospital-associated infections (e.g., central line-associated blood stream infection). Data collection relied on manual coding. Platforms typically did not provide an evidence-based rationale for measures collected, with no identifiable reports of co-designed, consensus-derived measures or consumer involvement in measure selection or prioritisation. CONCLUSIONS: Quality measurement in critically ill children lacks uniformity in definition which limits local and international benchmarking. Current surveillance activities for critically ill children focus heavily on outcome measurement, with process, structural, and patient-reported measures largely overlooked. Long-term outcome measures were not routinely collected. Harmonisation of paediatric intensive care unit quality measures is needed and can be achieved using prioritisation and consensus/co-design methods.

Supraventricular Tachycardia in Infants With Congenital Diaphragmatic Hernia: Prevalence, Associations, and Outcomes.

OBJECTIVES: To characterize the prevalence, associations, management, and outcomes of supraventricular tachycardia (SVT) in neonates with congenital diaphragmatic hernia (CDH). DESIGN: Retrospective chart and cardiology code review within a cohort of patients with CDH was used to define a subpopulation with atrial arrhythmia. SVT mechanisms were confirmed by electrocardiogram analysis. Cox proportional hazard regression identified risk factors for SVT and association with clinical outcomes. SETTING: Medical Surgical ICU in a single, tertiary center, Boston Children's Hospital. PATIENTS: Eligible patients included neonates presenting with classic Bochdalek posterolateral CDH between 2005 and 2017, excluding newborns with Morgagni hernia or late diagnoses of CDH (>28 d). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: SVT arose in 25 of 232 neonates with CDH, (11%); 14 of 25 infants (56%) had recurrent SVT; atrioventricular node-dependent tachycardia was the most frequent mechanism (32%). The majority (71%) of SVT episodes received intervention. Nine patients (36%) received preventative antiarrhythmic medications. SVT was associated with lower Apgar score at 1 min, structural heart disease, larger defect size, extracorporeal membrane oxygenation (ECMO) support, and prostaglandin therapy for ductal patency as well as hospital stay greater than or equal to 8 weeks and use of supplemental oxygen at discharge. CONCLUSIONS: SVT can occur in neonates with CDH and frequently requires treatment. Odds of occurrence are increased with greater CDH disease severity, ECMO, and prostaglandin use. In unadjusted logistic regression analysis, SVT was associated with adverse hospital outcomes, underscoring the importance of recognition and management in this vulnerable population.

Fluid Restriction Contributes to Poor Nutritional Adequacy in Patients With Congenital Heart Disease Receiving Renal Replacement Therapy.

OBJECTIVES: Critically ill patients receiving renal replacement therapy (RRT) in the pediatric cardiac intensive care unit (CICU) are at high risk for inadequate nutrition delivery. The objective of this study is to evaluate barriers to adequate energy and protein delivery in critically ill patients with congenital heart disease receiving RRT. METHODS: This is a single-center retrospective cohort study of patients receiving RRT in the CICU from 2011 to 2019. Energy and protein adequacy was recorded over the first 7 days of RRT. Adequacy was defined as delivery of >80% of the energy and protein targets during this time period. Patients who achieved adequacy were compared to those who did not. Multivariable logistic regression models were constructed to determine factors independently associated with energy and protein adequacy while receiving RRT. RESULTS: Sixty patients were included for analysis. Fifty-five patients (92%) achieved energy adequacy and 37 patients (62%) achieved protein adequacy. A higher weight-for-age z-score (WAZ) on admission to the CICU was the only independent predictor of inadequate energy intake (odds ratio 0.07, 95% confidence interval 0.01-0.58, P = .014); median WAZ was -1.17 versus +1.24 for those with adequate versus inadequate energy intake, respectively. Fluid restriction to <80% of maintenance fluid at the time of RRT initiation was more likely in patients with higher WAZ. Fluid restriction was the only independent predictor of inadequate protein intake (odds ratio 0.13, 95% confidence interval 0.02-0.7, P = .018); 5% versus 30% were fluid restricted in those with adequate versus inadequate protein intake, respectively. Azotemia was not associated with inadequate protein intake. Initiation of RRT did not allow for liberalization of fluid intake over the time period evaluated. CONCLUSIONS: Protein delivery was inadequate in 38% of children undergoing RRT in the CICU. Fluid restriction was associated with inadequate protein intake and higher WAZ was associated with inadequate energy intake.

Implementation of an Analgesia-Sedation Protocol Is Associated With Reduction in Midazolam Usage in the PICU.

OBJECTIVES: Examine the association of a revised analgesia-sedation protocol with midazolam usage in the PICU. DESIGN: A single-center nonrandomized before-after study. SETTING: PICU at a quaternary pediatric hospital (Boston Children's Hospital, Boston, MA). PATIENTS: Children admitted to the PICU who were mechanically ventilated for greater than 24 hours. The preimplementation cohort included 190 eligible patients admitted between July 29, 2017, and February 28, 2018, and the postimplementation cohort included 144 patients admitted between July 29, 2019, and February 28, 2020. INTERVENTIONS: Implementation of a revised analgesia-sedation protocol. MEASUREMENTS AND MAIN RESULTS: Our primary outcome, total dose of IV midazolam administered in mechanically ventilated patients up to day 14 of ventilation, decreased by 72% (95% CI [61-80%]; p < 0.001) in the postimplementation cohort. Dexmedetomidine usage increased 230% (95% CI [145-344%]) in the postimplementation cohort. Opioid usage, our balancing metric, was not significantly different between the two cohorts. There were no significant differences in ventilator-free days, PICU length of stay, rate of unplanned extubations, failed extubations, cardiorespiratory arrest events, and 24-hour readmissions to the PICU. CONCLUSIONS: We successfully implemented an analgesia-sedation protocol that primarily uses dexmedetomidine and intermittent opioids, and it was associated with significant decrease in overall midazolam usage in mechanically ventilated patients in the PICU. The intervention was not associated with changes in opioid usage or prevalence of adverse events.

Association Between Anticholinergic Drug Burden and Adequacy of Enteral Nutrition in Critically Ill, Mechanically Ventilated Pediatric Patients.

OBJECTIVES: Enteral nutrition delivery is limited by intolerance and interruptions in critically ill children. Anticholinergic properties of frequently administered medications may contribute to altered gastric motility and enteral nutrition intolerance in this population. We examined the association between the anticholinergic burden of administered medications using the Anticholinergic Drug Scale and adequacy of enteral nutrition delivery. DESIGN: Secondary analysis of data from a previously characterized PICU cohort. SETTING: Multidisciplinary PICU in a quaternary academic medical center. PATIENTS: Younger than or equal to 18 years, on mechanical ventilation and received enteral nutrition within the first 3 days of PICU admission. MEASUREMENTS AND MAIN RESULTS: Daily Anticholinergic Drug Scale score, demographic data, and clinical data were obtained from the primary study. Percent enteral energy adequacy ([kcal delivered ÷ kcal prescribed] × 100) during the first 3 days of PICU admission was calculated. Forty-two patients received enteral nutrition, with median age (interquartile range) 5 years (1.09-12.54 yr), and 62% were male. Median Anticholinergic Drug Scale score was inversely correlated with energy adequacy, with a median 9% decline in energy adequacy per 1-point increase in Anticholinergic Drug Scale score (coefficient, -9.3; 95% CI, -13.43 to -5.27; R2 = 0.35; p < 0.0001). Median hours of enteral nutrition interruptions directly correlated with Anticholinergic Drug Scale score (coefficient, 1.5; 95% CI, 0.531-2.54; R2 = 0.19; p = 0.004). Severity score was greater in patients with less than or equal to 25% enteral energy adequacy and directly correlated with median Anticholinergic Drug Scale score. CONCLUSIONS: Anticholinergic burden from medications administered in the PICU is a potentially modifiable factor for suboptimal enteral nutrition delivery.

Ultrasound Assessment of Quadriceps Femoris Muscle Thickness in Critically Ill Children.

OBJECTIVES: Evaluate the reliability of ultrasound to measure quadriceps femoris muscle thickness in critically ill children and to describe serial changes in quadriceps femoris muscle thickness in relation to fluid balance and nutritional intake. DESIGN: Prospective observational study. SETTING: Tertiary care children's hospital. PATIENTS: Inpatients age 3 months to 18 years recently admitted to the ICU who were sedated and mechanically ventilated at the time of the first ultrasound scan. METHODS: Prospective observational study to examine the reliability of averaged ultrasound measurements of quadriceps femoris muscle thickness. Change in average quadriceps femoris muscle thickness over time was correlated with fluid balance and nutritional intake. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Averaged quadriceps femoris muscle thickness demonstrated good to excellent reliability when comparing pediatric critical care providers to pediatric radiologists and when comparing between different pediatric critical care providers. We found no significant association between fluid balance over 1 or 3 days and change in quadriceps femoris muscle thickness over the same time frame. However, there was a significant association between percent of goal calories (p < 0.001) or percent of goal protein (p < 0.001) over 6 days and change in quadriceps femoris muscle thickness over the same time frame. CONCLUSIONS: Averaged ultrasound measurements of quadriceps femoris muscle thickness demonstrate good to excellent reliability, are not confounded by fluid balance, and are useful for tracking changes in muscle thickness that are associated with nutritional intake. Ultrasound-based assessment of quadriceps femoris is a clinically useful tool for evaluating muscle mass and may be a proxy for nutritional status.

eSIMPLER: A Dynamic, Electronic Health Record-Integrated Checklist for Clinical Decision Support During PICU Daily Rounds.

OBJECTIVES: Design, implement, and evaluate a rounding checklist with deeply embedded, dynamic electronic health record integration. DESIGN: Before-after quality-improvement study. SETTING: Quaternary PICU in an academic, free-standing children's hospital. PATIENTS: All patients in the PICU during daily morning rounds. INTERVENTIONS: Implementation of an updated dynamic checklist (eSIMPLER) providing clinical decision support prompts with display of relevant data automatically pulled from the electronic health record. MEASUREMENTS AND MAIN RESULTS: The prior daily rounding checklist, eSIMPLE, was implemented for 49,709 patient-days (7,779 patients) between October 30, 2011, and October 7, 2018. eSIMPLER was implemented for 5,306 patient-days (971 patients) over 6 months. Checklist completion rates were similar (eSIMPLE: 95% [95% CI, 88-98%] vs eSIMPLER: 98% [95% CI, 92-100%] of patient-days; p = 0.40). eSIMPLER required less time per patient (28 ± 1 vs 47 ± 24 s; p < 0.001). Users reported improved satisfaction with eSIMPLER (p = 0.009). Several checklist-driven process measures-discordance between electronic health record orders for stress ulcer prophylaxis and user-recorded indication for stress ulcer prophylaxis, rate of venous thromboembolism prophylaxis prescribing, and recognition of reduced renal function-improved during the eSIMPLER phase. CONCLUSIONS: eSIMPLER, a dynamic, electronic health record-informed checklist, required less time to complete and improved certain care processes compared with a prior, static checklist with limited electronic health record data. By focusing on the "Five Rights" of clinical decision support, we created a well-accepted clinical decision support tool that was integrated efficiently into daily rounds. Generalizability of eSIMPLER's effectiveness and its impact on patient outcomes need to be examined.

Sample Preparation for High-Throughput Urine Proteomics Using 96-Well Polyvinylidene Fluoride (PVDF) Membranes.

Proteomics analysis of urine samples allows for studying the impact of system perturbation. However, meaningful proteomics-based biomarker discovery projects often require the analysis of large patient cohorts with hundreds of samples to describe the biological variability. Thus, robust high-throughput sample processing methods are a prerequisite for clinical proteomics pipelines that minimize experimental bias due to individual sample processing methods. Herein we describe a high-throughput method for parallel 96-well plate-based processing of urine samples for subsequent LC/MS-based proteomic analyses. Protein digestion and subsequent sample processing steps are efficiently performed in 96-well polyvinylidene fluoride (PVDF) membrane plate allowing for the use of vacuum manifolds for rapid liquid transfer, and multichannel pipettes and/or liquid handing robots. In this chapter we make available a detailed step-by-step protocol for our 'MStern blotting' sample processing strategy applied to patient urine samples followed by mass spectrometry-based proteomics analysis. Subsequently, we provide an example application using minimal volume of urine samples (e.g. 150 µL) collected from children pre and post thoracotomy to identify the predominant sites of protein catabolism and aid in the design of therapies to ameliorate protein catabolism and breakdown during critical illness. Furthermore, we demonstrate how the systemic state is reflected in the urine as an easily obtainable, stable, and safe biofluid.

Biomarkers in critical care nutrition.

The goal of nutrition support is to provide the substrates required to match the bioenergetic needs of the patient and promote the net synthesis of macromolecules required for the preservation of lean mass, organ function, and immunity. Contemporary observational studies have exposed the pervasive undernutrition of critically ill patients and its association with adverse clinical outcomes. The intuitive hypothesis is that optimization of nutrition delivery should improve ICU clinical outcomes. It is therefore surprising that multiple large randomized controlled trials have failed to demonstrate the clinical benefit of restoring or maximizing nutrient intake. This may be in part due to the absence of biological markers that identify patients who are most likely to benefit from nutrition interventions and that monitor the effects of nutrition support. Here, we discuss the need for practical risk stratification tools in critical care nutrition, a proposed rationale for targeted biomarker development, and potential approaches that can be adopted for biomarker identification and validation in the field.

Current State of Nutrition Education in Pediatric Critical Care Medicine Fellowship Programs in the United States and Canada.

OBJECTIVES: To assess the current state of nutrition education provided during pediatric critical care medicine fellowship. DESIGN: Cross-sectional survey. SETTING: Program directors and fellows from pediatric critical care medicine fellowship programs in America and Canada. SUBJECTS: Seventy current pediatric critical care medicine fellows and twenty-five pediatric critical care medicine fellowship program directors were invited to participate. INTERVENTIONS: Participants were asked demographic questions related to their fellowship programs, currently utilized teaching methods, perceptions regarding adequacy and effectiveness of current nutrition education, and levels of fellow independence, comfort, confidence, and expectations in caring for the nutritional needs of patients. MEASUREMENTS AND MAIN RESULTS: Surveys were sent to randomly selected program directors and fellows enrolled in pediatric critical care medicine fellowship programs in America and Canada. Twenty program directors (80%) and 60 fellows (86%) responded. Ninety-five percent of programs (19/20) delivered a formal nutrition curriculum; no curriculum was longer than 5 hours per academic year. Self-reported fellow comfort with nutrition topics did not improve over the course of fellowship (p = 0.03), with the exception of nutritional aspects of special diets. Sixty-five percent of programs did not hold fellows responsible for writing daily parenteral nutrition prescriptions. There was an inverse relationship between total number of fellows in a pediatric critical care medicine program and levels of comfort in ability to provide parenteral nutrition support (p = 0.01). Program directors perceived their nutritional curriculum to be more effective than did their fellows (p ≤ 0.001). CONCLUSIONS: Nutrition education was reported as highly underrepresented in pediatric critical care medicine fellowship curricula. The majority of programs rely on allied health care professionals to prescribe parenteral nutrition, which may influence trainee independence in the provision of nutritional therapies. Improving the format of current nutrition curriculums, by relying on more active teaching methods, may improve the delivery and efficacy of nutrition education. The impact of novel training interventions on improving the competency and safety of enteral and parenteral nutrition delivery in the PICU must be further examined.

Early Enteral Nutrition Is Associated With Improved Clinical Outcomes in Critically Ill Children: A Secondary Analysis of Nutrition Support in the Heart and Lung Failure-Pediatric Insulin Titration Trial.

OBJECTIVES: The impact of early enteral nutrition on clinical outcomes in critically ill children has not been adequately described. We hypothesized that early enteral nutrition is associated with improved clinical outcomes in critically ill children. DESIGN: Secondary analysis of the Heart and Lung Failure-Pediatric Insulin Titration randomized controlled trial. SETTING: Thirty-five PICUs. PATIENTS: Critically ill children with hyperglycemia requiring inotropic support and/or invasive mechanical ventilation who were enrolled for at least 48 hours with complete nutrition data. INTERVENTIONS: Subjects received nutrition via guidelines that emphasized enteral nutrition and were classified into early enteral nutrition (enteral nutrition within 48 hr of study randomization) and no early enteral nutrition (enteral nutrition after 48 hr of study randomization, or no enteral nutrition at any time). MEASUREMENTS AND MAIN RESULTS: Of 608 eligible subjects, 331 (54%) received early enteral nutrition. Both early enteral nutrition and no early enteral nutrition groups had similar daily caloric intake over the first 8 study days (median, 36 vs 36 kcal/kg/d; p = 0.93). After controlling for age, body mass index z scores, primary reason for ICU admission, severity of illness, and mean Vasopressor-Inotrope Score at the time of randomization, and adjusting for site, early enteral nutrition was associated with lower 90-day hospital mortality (8% vs 17%; p = 0.007), more ICU-free days (median, 20 vs 17 d; p = 0.02), more hospital-free days (median, 8 vs 0 d; p = 0.003), more ventilator-free days (median, 21 vs 19 d; p = 0.003), and less organ dysfunction (median maximum Pediatric Logistic Organ Dysfunction, 11 vs 12; p < 0.001). CONCLUSIONS: In critically ill children with hyperglycemia requiring inotropic support and/or mechanical ventilation, early enteral nutrition was independently associated with better clinical outcomes.

Surviving Sepsis Campaign International Guidelines for the Management of Septic Shock and Sepsis-Associated Organ Dysfunction in Children.

OBJECTIVES: To develop evidence-based recommendations for clinicians caring for children (including infants, school-aged children, and adolescents) with septic shock and other sepsis-associated organ dysfunction. DESIGN: A panel of 49 international experts, representing 12 international organizations, as well as three methodologists and three public members was convened. Panel members assembled at key international meetings (for those panel members attending the conference), and a stand-alone meeting was held for all panel members in November 2018. A formal conflict-of-interest policy was developed at the onset of the process and enforced throughout. Teleconferences and electronic-based discussion among the chairs, co-chairs, methodologists, and group heads, as well as within subgroups, served as an integral part of the guideline development process. METHODS: The panel consisted of six subgroups: recognition and management of infection, hemodynamics and resuscitation, ventilation, endocrine and metabolic therapies, adjunctive therapies, and research priorities. We conducted a systematic review for each Population, Intervention, Control, and Outcomes question to identify the best available evidence, statistically summarized the evidence, and then assessed the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. We used the evidence-to-decision framework to formulate recommendations as strong or weak, or as a best practice statement. In addition, "in our practice" statements were included when evidence was inconclusive to issue a recommendation, but the panel felt that some guidance based on practice patterns may be appropriate. RESULTS: The panel provided 77 statements on the management and resuscitation of children with septic shock and other sepsis-associated organ dysfunction. Overall, six were strong recommendations, 52 were weak recommendations, and nine were best-practice statements. For 13 questions, no recommendations could be made; but, for 10 of these, "in our practice" statements were provided. In addition, 49 research priorities were identified. CONCLUSIONS: A large cohort of international experts was able to achieve consensus regarding many recommendations for the best care of children with sepsis, acknowledging that most aspects of care had relatively low quality of evidence resulting in the frequent issuance of weak recommendations. Despite this challenge, these recommendations regarding the management of children with septic shock and other sepsis-associated organ dysfunction provide a foundation for consistent care to improve outcomes and inform future research.

Incorporating the latest pediatric nutrition support guidelines into clinical practice.

Optimal nutrition support in critically ill children is associated with improved outcomes and decreased mortality. Nutrition provision often competes with other care priorities in critically ill patients. The 2017 Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Pediatric Critically Ill Patient supplement clinician knowledge and inform best practices for nutrition therapy in this vulnerable patient population.