Protein, Energy and Their Interaction in Critically Ill Children

Critically ill patients are in a catabolic state, characterized by three major metabolic changes. First, there is an increased protein turnover with enhanced hepatic protein synthesis and muscle protein breakdown. Second, during critical illness there is increased lipolysis, or the breakdown of triglycerides to free fatty acids (FFA) and glycerol. And third, insulin resistance causes hyperglycemia due to ongoing endogenous glucose production (glycogenolysis and gluconeogenesis) and blunted peripheral uptake. These metabolic derangements are caused by various endogenous and exogenous triggers, including increased inflammatory cytokines (Tumor Necrosis Factor α, interleukin-1, interleukin-6, and interleukin-8), catecholamines and glucocorticoids, all in which insulin resistance plays a central role.This response to injury is universal and has been beneficial all through evolution at the acute onset of severe disease or trauma. However, modern medicine has improved survival rate and critical illness has bec

The role of parenteral nutrition in paediatric critical care, and its consequences on recovery

The goal of nutritional support during critical illness is to provide the appropriate amount of nutrition accounting for the acute, stable and recovery phase in order to accelerate recovery and to improve short-term and long-term outcomes. Although the preferred route to provide nutritional support during paediatric critical illness is via enteral route, reaching target intakes is often difficult due to (perceived) feeding intolerance, fluid restriction, and interruptions around procedures. Because undernourishment in these children has been associated with impaired outcome, parenteral nutrition (PN) has therefore been viewed as an optimal alternative for reaching early and high nutritional targets. However, PN recommendations regarding timing, dose and composition varied widely and were based on studies using intermediate or surrogate endpoints and observational studies. It was not until the paediatric early versus late PN in critically ill children (PEPaNIC) randomized controlled trial (RCT) that the advice to reach high and early macronutrient goals via PN was challenged. The PEPaNIC study showed that omitting supplemental PN during the first week of paediatric intensive care unit (PICU) admission as compared with early initiation of PN (&lt;24 hours) reduced new acquired infections and accelerated recovery. The provision of amino acids in particular was negatively associated with short-term outcomes, probably explained by the suppression of the activation of autophagy. Autophagy is an evolutionary conserved intracellular degradation process and it is crucial for maintaining cellular integrity and function, which becomes even more important during acute stress. Results of the long-term PEPaNIC follow-up study showed that withholding early PN did not negatively affect anthropometrics and health status but improved neurocognitive and psychosocial development 2 and 4 years later. Current guidelines therefore advise to consider withholding parenteral macronutrients for the first week of PICU admission, while providing micronutrients. Although parenteral restriction during the first week of critical illness has been found beneficial, further research beyond the acute phase is warranted to determine the best role of PN in terms of optimal timing, dose and composition in order to improve short-term recovery and long-term developmental outcomes.</p

Intermittent feeding with an overnight fast versus 24-h feeding in critically ill neonates, infants, and children:An open-label, single-centre, randomised controlled trial

Background &amp; aims: Critically ill children are fed day and night, assuming this improves enteral tolerance and the probability of achieving nutritional goals. It was previously shown that a fasting response, reflected by increased ketosis, at least partly explained the beneficial outcome of delayed initiation of supplemental parenteral nutrition. This study aims to investigate whether an overnight fast increases ketosis and is feasible and safe in critically ill children. Methods: The Continuous versus Intermittent Nutrition in Paediatric Intensive Care (ContInNuPIC) study is a randomised controlled trial in a tertiary referral Paediatric Intensive Care Unit (PICU) in the Netherlands. Critically ill children (term newborn-18 years) with an expected PICU stay ≥48 h, dependent on artificial nutrition, were eligible. Participants were randomly assigned (1:1, stratified for age group) to intermittent feeding, with interruption of feedings during an age-dependent overnight period of eight to 12 h, or to continuous feeding, with the administration of feedings day and night. In both groups, similar daily caloric targets were pursued. For children younger than one year, mandatory minor glucose infusions were provided during fasting. The primary outcome was the feasibility, defined as two conditions (1): a significant difference in the patients’ highest daily ketone (3-β-hydroxybutyrate, BHB) levels during each overnight period, and (2): non-inferiority regarding daily caloric intake, examined using a two-part mixed-effects model with a predefined non-inferiority margin of 33%, in an intention-to-treat analysis. The study is registered in the Netherlands Trial Register (NL7877). Results: Between May 19, 2020, and July 13, 2022, 140 critically ill children, median (first quartile; third quartile) age 0.3 (0.1; 2.7) years, were randomised to intermittent (n = 67) or continuous feeding (n = 73). In the intermittent feeding group, BHB levels were significantly higher (median 0.4 (0.2; 1.0) vs. 0.3 (0.1; 0.7) mmol/L, p &lt; 0.001). The ratio of total caloric intake in the intermittent feeding group to the intake in the continuous feeding group was not consistently significantly more than 0.67, thus not proving non-inferiority. No severe, resistant hypoglycaemic events, nor severe gastrointestinal complications related to the intervention occurred, and feeding intolerance did not occur more often in the intermittent than in the continuous feeding group. Conclusion: Compared with day and night feeding, intermittent feeding with an overnight fast and mandatory glucose infusion for children younger than one year marginally increased ketosis and did not lead to more hypoglycaemic incidents in critically ill children. Because non-inferiority regarding daily caloric intake was not proven, the feasibility of an overnight fast could not be shown in the current study. However, as feeding intolerance did not increase during the condensed feeding periods, the nutritional intake was probably limited by the prescription of nutrition and interruptions. More research is needed to determine the optimal level and duration of clinically relevant ketosis and the best method to achieve this.</p

Elevated High-Sensitivity Troponin and NT-proBNP Values in Febrile Children

Objectives The COVID-19 pandemic and subsequent rise of multisystem inflammatory syndrome in children have raised interest in high-sensitivity troponin (hs-TnT) and N-terminal probrain natriuretic peptide (NT-proBNP) because these have been found to be elevated in many cases of multisystem inflammatory syndrome in children. Our aim was to study hs-TnT and NT-proBNP concentrations in febrile children not affected by COVID-19. Methods We retrospectively measured cardiac markers, hs-TnT, and NT-proBNP in leftover blood samples of febrile children (0-18 years) diagnosed and treated in a single-center emergency department (ED) (N = 67) and pediatric intensive care unit (PICU) (N = 19) that participated in a multicenter, prospective study of infection biomarkers (PERFORM). Results Concentrations of hs-TnT, median 1.8 ng/L (interquartile range [IQR], 0.0-15.1), and NT-proBNP, 194 pg/mL (IQR, 54.9-706), were higher in febrile children than in controls (N = 25, hs-TnT 0.0 [IQR, 0-0]; NT-proBNP 56.3 [IQR, 29.7-109], both P &lt; 0.001), whereas PICU patients had higher concentrations (hs-TnT 15.1 [IQR, 10.3-102] and NT-proBNP 828 [IQR, 657-4712], both P &lt; 0.001) than ED patients (hs-TnT 0 [IQR, 0-7.4] and NT-proBNP 104 [IQR, 39.5-363]). No differences were found between viral and bacterial infections. Highest concentrations were found in children with either comorbidity predisposing to elevated concentrations (eg, chronic cardiac or renal disease) or children with critical illness or multiorgan failure such as those with septic shock. Conclusions Concentrations of hs-TnT and NT-proBNP are often elevated in febrile children with different causes of fever. Concentrations were higher in children admitted to the PICU than in children attending the ED, and seem to reflect disease severity rather than the underlying cause of fever.</p

Elevated High-Sensitivity Troponin and NT-proBNP Values in Febrile Children

Objectives The COVID-19 pandemic and subsequent rise of multisystem inflammatory syndrome in children have raised interest in high-sensitivity troponin (hs-TnT) and N-terminal probrain natriuretic peptide (NT-proBNP) because these have been found to be elevated in many cases of multisystem inflammatory syndrome in children. Our aim was to study hs-TnT and NT-proBNP concentrations in febrile children not affected by COVID-19. Methods We retrospectively measured cardiac markers, hs-TnT, and NT-proBNP in leftover blood samples of febrile children (0-18 years) diagnosed and treated in a single-center emergency department (ED) (N = 67) and pediatric intensive care unit (PICU) (N = 19) that participated in a multicenter, prospective study of infection biomarkers (PERFORM). Results Concentrations of hs-TnT, median 1.8 ng/L (interquartile range [IQR], 0.0-15.1), and NT-proBNP, 194 pg/mL (IQR, 54.9-706), were higher in febrile children than in controls (N = 25, hs-TnT 0.0 [IQR, 0-0]; NT-proBNP 56.3 [IQR, 29.7-109], both P &lt; 0.001), whereas PICU patients had higher concentrations (hs-TnT 15.1 [IQR, 10.3-102] and NT-proBNP 828 [IQR, 657-4712], both P &lt; 0.001) than ED patients (hs-TnT 0 [IQR, 0-7.4] and NT-proBNP 104 [IQR, 39.5-363]). No differences were found between viral and bacterial infections. Highest concentrations were found in children with either comorbidity predisposing to elevated concentrations (eg, chronic cardiac or renal disease) or children with critical illness or multiorgan failure such as those with septic shock. Conclusions Concentrations of hs-TnT and NT-proBNP are often elevated in febrile children with different causes of fever. Concentrations were higher in children admitted to the PICU than in children attending the ED, and seem to reflect disease severity rather than the underlying cause of fever.</p

Assessment of aberrant DNA methylation two years after paediatric critical illness:a pre-planned secondary analysis of the international PEPaNIC trial

Critically ill children requiring intensive care suffer from impaired physical/neurocognitive development 2 y later, partially preventable by omitting early use of parenteral nutrition (early-PN) in the paediatric intensive-care-unit (PICU). Altered methylation of DNA from peripheral blood during PICU-stay provided a molecular basis hereof. Whether DNA-methylation of former PICU patients, assessed 2 y after critical illness, is different from that of healthy children remained unknown. In a pre-planned secondary analysis of the PEPaNIC-RCT (clinicaltrials.gov-NCT01536275) 2-year follow-up, we assessed buccal-mucosal DNA-methylation (Infinium-HumanMethylation-EPIC-BeadChip) of former PICU-patients (N = 406 early-PN; N = 414 late-PN) and matched healthy children (N = 392). CpG-sites differentially methylated between groups were identified with multivariable linear regression and differentially methylated DNA-regions via clustering of differentially methylated CpG-sites using kernel-estimates. Analyses were adjusted for technical variation and baseline risk factors, and corrected for multiple testing (false-discovery-rate <0.05). Differentially methylated genes were functionally annotated (KEGG-pathway database), and allocated to three classes depending on involvement in physical/neurocognitive development, critical illness and intensive medical care, or pre-PICU-admission disorders. As compared with matched healthy children, former PICU-patients showed significantly different DNA-methylation at 4047 CpG-sites (2186 genes) and 494 DNA-regions (468 genes), with most CpG-sites being hypomethylated (90.3%) and with an average absolute 2% effect-size, irrespective of timing of PN initiation. Of the differentially methylated KEGG-pathways, 41.2% were related to physical/neurocognitive development, 32.8% to critical illness and intensive medical care and 26.0% to pre-PICU-admission disorders. Two years after critical illness in children, buccal-mucosal DNA showed abnormal methylation of CpG-sites and DNA-regions located in pathways known to be important for physical/neurocognitive development

Predicting adverse long-term neurocognitive outcomes after pediatric intensive care unit admission

Background and objective: Critically ill children may suffer from impaired neurocognitive functions years after ICU (intensive care unit) discharge. To assess neurocognitive functions, these children are subjected to a fixed sequence of tests. Undergoing all tests is, however, arduous for former pediatric ICU patients, resulting in interrupted evaluations where several neurocognitive deficiencies remain undetected. As a solution, we propose using machine learning to predict the optimal order of tests for each child, reducing the number of tests required to identify the most severe neurocognitive deficiencies. Methods: We have compared the current clinical approach against several machine learning methods, mainly multi-target regression and label ranking methods. We have also proposed a new method that builds several multi-target predictive models and combines the outputs into a ranking that prioritizes the worse neurocognitive outcomes. We used data available at discharge, from children who participated in the PEPaNIC-RCT trial (ClinicalTrials.gov-NCT01536275), as well as data from a 2-year follow-up study. The institutional review boards at each participating site have also approved this follow-up study (ML8052; NL49708.078; Pro00038098). Results: Our proposed method managed to outperform other machine learning methods and also the current clinical practice. Precisely, our method reaches approximately 80% precision when considering top-4 outcomes, in comparison to 65% and 78% obtained by the current clinical practice and the state-of-the-art method in label ranking, respectively. Conclusions: Our experiments demonstrated that machine learning can be competitive or even superior to the current testing order employed in clinical practice, suggesting that our model can be used to severely reduce the number of tests necessary for each child. Moreover, the results indicate that possible long-term adverse outcomes are already predictable as early as at ICU discharge. Thus, our work can be seen as the first step to allow more personalized follow-up after ICU discharge leading to preventive care rather than curative.</p

Quality improvement intervention to stimulate early mobilization of critically ill children

Background: Immobility during hospital stay is associated with muscle weakness, delirium, and delayed neurocognitive recovery. Early mobilization of critically ill adults improves their physical functioning and shortens the duration of mechanical ventilation. However, comparable research in children is lacking. Aims: To determine the effects of the implementation of an early mobilization (EM) program on mobility activities for critically ill children and to explore barriers and facilitators and clinical outcomes before and after implementation. Study design: A prospective single-centre before-and-after study. Methods: This study was conducted in a PICU of a large tertiary hospital. Children aged from 3 months to 18 years, with an expected stay of ≥3 days were eligible to participate. In the “before” phase, participants received usual care; in the “after” phase we implemented a multicomponent, multidisciplinary EM protocol. The primary outcome was a change in the process outcome “mobilization activities”. Secondary outcomes were PICU staff opinions on mobilization (survey), safety, process measures, involvement of parents and physical therapist, and clinical outcomes (sedative use and prevalence of delirium). Results: A total of 113 children were included; 55 before and 58 after, with a median age of 31 months (IQR: 10–103) and 35 months (IQR: 7–152), respectively. The number of mobilization activities (per patient per day) had significantly increased from 5 (IQR: 2–7) to 6 (IQR: 4–8) (U = 272185.0; p &lt;.001). PT consultations for mobilization had significantly increased from 23.6% (13/55) to 46.5% (27/58) (X2 = 6.48; p =.011). In both phases, no mobilization-related adverse events were documented. The survey showed that PICU staff found EM of critically ill children useful and feasible. In the after phase, PICU staff rated the perceived benefit of the support of the physical therapist during mobilization activities significantly higher than in the before phase (X2 = 34.80; p &lt;.001). Conclusions: Implementation of a structured EM program for critically ill children is feasible and safe. Relevance to clinical practice: It is suggested to start the implementation of a structed EM program with the idendentification of local barriers and facilitators by an interdisciplinary PICU team. Further, an increased presence of physiotherapists on the PICU would improve mobilisation levels, and facilitate mobilisation in critically ill children. Also, they can support and advice PICU nurses and parents in mobilising children.</p

Predicting adverse long-term neurocognitive outcomes after pediatric intensive care unit admission

Background and objective: Critically ill children may suffer from impaired neurocognitive functions years after ICU (intensive care unit) discharge. To assess neurocognitive functions, these children are subjected to a fixed sequence of tests. Undergoing all tests is, however, arduous for former pediatric ICU patients, resulting in interrupted evaluations where several neurocognitive deficiencies remain undetected. As a solution, we propose using machine learning to predict the optimal order of tests for each child, reducing the number of tests required to identify the most severe neurocognitive deficiencies. Methods: We have compared the current clinical approach against several machine learning methods, mainly multi-target regression and label ranking methods. We have also proposed a new method that builds several multi-target predictive models and combines the outputs into a ranking that prioritizes the worse neurocognitive outcomes. We used data available at discharge, from children who participated in the PEPaNIC-RCT trial (ClinicalTrials.gov-NCT01536275), as well as data from a 2-year follow-up study. The institutional review boards at each participating site have also approved this follow-up study (ML8052; NL49708.078; Pro00038098). Results: Our proposed method managed to outperform other machine learning methods and also the current clinical practice. Precisely, our method reaches approximately 80% precision when considering top-4 outcomes, in comparison to 65% and 78% obtained by the current clinical practice and the state-of-the-art method in label ranking, respectively. Conclusions: Our experiments demonstrated that machine learning can be competitive or even superior to the current testing order employed in clinical practice, suggesting that our model can be used to severely reduce the number of tests necessary for each child. Moreover, the results indicate that possible long-term adverse outcomes are already predictable as early as at ICU discharge. Thus, our work can be seen as the first step to allow more personalized follow-up after ICU discharge leading to preventive care rather than curative.</p