Impact of critical illness and withholding of early parenteral nutrition in the pediatric intensive care unit on long-term physical performance of children: a 4-year follow-up of the PEPaNIC randomized controlled trial

Background

Many critically ill children face long-term developmental impairments. The PEPaNIC trial attributed part of the problems at the level of neurocognitive and emotional/behavioral development to early use of parenteral nutrition (early-PN) in the PICU, as compared with withholding it for 1 week (late-PN). Insight in long-term daily life physical functional capacity after critical illness is limited. Also, whether timing of initiating PN affects long-term physical function of these children remained unknown.

Methods

This preplanned follow-up study of the multicenter PEPaNIC randomized controlled trial subjected 521 former critically ill children (253 early-PN, 268 late-PN) to quantitative physical function tests 4 years after PICU admission in Leuven or Rotterdam, in comparison with 346 age- and sex-matched healthy children. Tests included handgrip strength measurement, timed up-and-go test, 6-min walk test, and evaluation of everyday overall physical activity with an accelerometer. We compared these functional measures for the former critically ill and healthy children and for former critically ill children randomized to late-PN versus early-PN, with multivariable linear or logistic regression analyses adjusting for risk factors.

Results

As compared with healthy children, former critically ill children showed less handgrip strength (p < 0.0001), completed the timed up-and-go test more slowly (p < 0.0001), walked a shorter distance in 6 min (p < 0.0001) during which they experienced a larger drop in peripheral oxygen saturation (p ≤ 0.026), showed a lower energy expenditure (p ≤ 0.024), performed more light and less moderate physical activity (p ≤ 0.047), and walked fewer steps per day (p = 0.0074). Late-PN as compared with early-PN did not significantly affect these outcomes.

Conclusions

Four years after PICU admission, former critically ill children showed worse physical performance as compared with healthy children, without impact of timing of supplemental PN in the PICU. This study provides further support for de-implementing the early use of PN in the PICU.

Trial registration ClinicalTrials.gov, NCT01536275; registered on February 22, 2012.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04010-3.

PN Administration in Critically Ill Children in Different Phases of the Stress Response

Nutritional support is an important part of the treatment of critical ill children and the phase of disease has to be taken into account. The metabolic stress response during acute critical illness is characterized by severe catabolism. So far, there is no evidence that the acute catabolic state can be prevented with nutritional support. The Pediatric ’Early versus Late Parenteral Nutrition’ (PEPaNIC) trial showed that withholding supplemental parenteral nutrition (PN) during the first week in critically ill children, when enteral nutrition was not sufficient, prevented infections and shortened the stay in the pediatric intensive care unit (PICU) and the hospital. A follow-up performed 2 and 4 years later showed that withholding parenteral nutrition (PN) also improved several domains of the neurocognitive outcome of the children. Current international guidelines recommend considering withholding parenteral macronutrients during the first week of pediatric critical illness, while providing micronutrients. These guidelines also recommend upper and lower levels of intake of macronutrients and micronutrients if PN is administered.

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 < .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 < .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.

Role of extracorporeal membrane oxygenation in pediatric cancer patients: a systematic review and meta-analysis of observational studies

Background

The use of extracorporeal membrane oxygenation (ECMO) in pediatric patients with underlying malignancies remains controversial. However, in an era in which the survival rates for children with malignancies have increased significantly and several recent reports have demonstrated effective ECMO use in children with cancer, we aimed to estimate the outcome and complications of ECMO treatment in these children.

Methods

We searched MEDLINE, Embase and CINAHL databases for studies on the use ECMO in pediatric patients with an underlying malignancy from inception to September 2020. This review was conducted in adherence to Preferred Reporting Items for Systematic Review and Meta-Analysis statement. Study eligibility was independently assessed by two authors and disagreements resolved by a third author. Included studies were evaluated for quality using the Newcastle–Ottawa Scale (NOS). Random effects meta-analyses (DerSimonian and Laird) were performed. The primary outcomes were mortality during ECMO or hospital mortality.

Results

Thirteen retrospective, observational cohort studies were included, most of moderate quality (625 patients). The commonest indication for ECMO was severe respiratory failure (92%). Pooled mortality during ECMO was 55% (95% confidence interval [CI], 47–63%) and pooled hospital mortality was 60% (95% CI 54–67%). Although heterogeneity among the included studies was low, confidence intervals were large. In addition, the majority of the data were derived from registries with overlapping patients which were excluded for the meta-analyses to prevent resampling of the same participants across the included studies. Finally, there was a lack of consistent complications reporting among the studies.

Conclusion

Significantly higher mortalities than in general PICU patients was reported with the use of ECMO in children with malignancies. Although these results need to be interpreted with caution due to the lack of granular data, they suggest that ECMO appears to represents a viable rescue option for selected patients with underlying malignancies. There is an urgent need for additional data to define patients for whom ECMO may provide benefit or harm.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-00983-0.

Phasing out DEHP from plastic indwelling medical devices used for intensive care: Does it reduce the long-term attention deficit of critically ill children?

BACKGROUND

Children who have been critically ill face long-term developmental impairments. Iatrogenic exposure to di(2-ethylhexyl)phthalate (DEHP), a plasticizer leaching from plastic indwelling medical devices used in the pediatric intensive care unit (PICU), has been associated with the pronounced attention deficit observed in children 4 years after critical illness. As concerns about DEHP toxicity increased, governmental authorities urged the phase out of DEHP in indwelling medical devices and replacement with alternative plasticizers. We hypothesized that exposure to DEHP decreased over the years, attenuating the pronounced long-term attention deficit of these vulnerable children.

METHODS

We compared plasma concentrations of 3 oxidative DEHP metabolites (5cx-MEPP, 5OH-MEHP, 5oxo-MEHP) on the last PICU day in 216 patients who participated in the Tight Glucose Control study (2004-2007) and 334 patients who participated in the PEPaNIC study (2012-2015) and survived PICU stay. Corresponding minimal exposures to these metabolites (plasma concentration multiplied with number of days in PICU) were also evaluated. In patients with 4-year follow-up data, we compared measures of attention (standardized reaction times and consistency). Comparisons were performed with univariable analyses and multivariable linear regression analyses adjusted for baseline risk factors.

RESULTS

In the PEPaNIC patients, last PICU day plasma concentrations of 5cx-MEPP, 5OH-MEHP, 5oxo-MEHP and their sum, and corresponding minimal exposures, were reduced to 17-69% of those in the Tight Glucose Control study (p < 0.0001). Differences remained significant after multivariable adjustment (p ≤ 0.001). PEPaNIC patients did not show better attention than patients in the Tight Glucose Control study, also not after multivariable adjustment for risk factors.

CONCLUSION

Exposure of critically ill children to DEHP in the PICU decreased over the years, but the lower exposure did not translate into improved attention 4 years later. Whether the residual exposure may still be toxic or whether the plasticizers replacing DEHP may not be safe for neurodevelopment needs further investigation.

A blend of 3 mushrooms dose-dependently increases butyrate production by the gut microbiota

The gut microbiota has been indicated to play a crucial role in health and disease. Apart from changes in composition between healthy individuals and those with a disease or disorder, it has become clear that also microbial activity is important for health. For instance, butyrate has been proven to be beneficial for health, because, amongst others, it is a substrate for the colonocytes, and modulates the host's immune system and metabolism. Here, we studied the effect of a blend of three mushrooms (Ganoderma lucidum GL AM P-38, Grifola frondosa GF AM P36 and Pleurotus ostreatus PO AM-GP37)) on gut microbiota composition and activity in a validated, dynamic, computer-controlled in vitro model of the colon (TIM-2). Predigested mushroom blend at three doses (0.5, 1.0 and 1.5 g/day of ingested mushroom blend) was fed to a pooled microbiota of healthy adults for 72 h, and samples were taken every day for microbiota composition (sequencing of amplicons of the V3-V4 region of the 16S rRNA gene) and activity (short-chain fatty acid (SCFA) production). The butyrate producing genera Lachnospiraceae UCG-004, Lachnoclostridium, Ruminococcaceae UCG-002 and Ruminococcaceae NK4A214-group are all dose-dependently increased when the mushroom blend was fed. Entirely in line with the increase of these butyrate-producers, the cumulative amount of butyrate also dose-dependently increased, to roughly twice the amount compared to the control (medium without mushroom blend) on the high-dose mushroom blend. Butyrate proportionally made up 53.1% of the total SCFA upon feeding the high-dose mushroom blend, compared to 27% on the control medium. In conclusion, the (polysaccharides in the) mushroom blend led to substantial increase in butyrate by the gut microbiota. These results warrant future mechanistic research on the mushroom blend, as butyrate is considered to be one of the microbial metabolites that contributes to health, by increasing barrier function and modulating inflammation.

Practical strategies to implement the ESPNIC Nutrition Clinical recommendations into PICU practice

BACKGROUND

The European Society of Pediatric and Neonatal Intensive Care (ESPNIC) published 32 clinical recommendations around supporting nutrition in critically ill children following an extensive review of the literature online in January 2020. The challenge now is to engage with paediatric intensive care unit teams to implement these into their practice.

OBJECTIVE

This practical implementation guide uses a recognised implementation model to guide pediatric intensive care professionals to implement these evidence-based clinical recommendations into clinical practice.

RESULTS AND CONCLUSIONS

We use the Pronovost implementation of evidence into practice model to provide a practical framework with associated documents to facilitate PICU healthcare professional's implementation of these clinical recommendations into PICU practice. The paper is structured around the four steps in this model: summarising the evidence, identifying local barriers to implementation, measuring performance and ensuring all patients receive the intervention and useful checklists for implementation and compliance monitoring are provided, in addition to tables outlining key professional roles and responsibilities around nutrition in the paediatric Intensive care Unit.

Caring for Critically Ill Children With Suspected or Proven Coronavirus Disease 2019 Infection: Recommendations by the Scientific Sections' Collaborative of the European Society of Pediatric and Neonatal Intensive Care

OBJECTIVES

In children, coronavirus disease 2019 is usually mild but can develop severe hypoxemic failure or a severe multisystem inflammatory syndrome, the latter considered to be a postinfectious syndrome, with cardiac involvement alone or together with a toxic shock like-presentation. Given the novelty of severe acute respiratory syndrome coronavirus 2, the causative agent of the recent coronavirus disease 2019 pandemic, little is known about the pathophysiology and phenotypic expressions of this new infectious disease nor the optimal treatment approach.

STUDY SELECTION

From inception to July 10, 2020, repeated PubMed and open Web searches have been done by the scientific section collaborative group members of the European Society of Pediatric and Neonatal Intensive Care.

DATA EXTRACTION

There is little in the way of clinical research in children affected by coronavirus disease 2019, apart from descriptive data and epidemiology.

DATA SYNTHESIS

Even though basic treatment and organ support considerations seem not to differ much from other critical illness, such as pediatric septic shock and multiple organ failure, seen in PICUs, some specific issues must be considered when caring for children with severe coronavirus disease 2019 disease.

CONCLUSIONS

In this clinical guidance article, we review the current clinical knowledge of coronavirus disease 2019 disease in critically ill children and discuss some specific treatment concepts based mainly on expert opinion based on limited experience and the lack of any completed controlled trials in children at this time.

Effect of withholding early parenteral nutrition in PICU on ketogenesis as potential mediator of its outcome benefit

Background

In critically ill children, omitting early use of parenteral nutrition (late-PN versus early-PN) reduced infections, accelerated weaning from mechanical ventilation, and shortened PICU stay. We hypothesized that fasting-induced ketogenesis mediates these benefits.

Methods

In a secondary analysis of the PEPaNIC RCT (N = 1440), the impact of late-PN versus early-PN on plasma 3-hydroxybutyrate (3HB), and on blood glucose, plasma insulin, and glucagon as key ketogenesis regulators, was determined for 96 matched patients staying ≥ 5 days in PICU, and the day of maximal 3HB-effect, if any, was identified. Subsequently, in the total study population, plasma 3HB and late-PN-affected ketogenesis regulators were measured on that average day of maximal 3HB effect. Multivariable Cox proportional hazard and logistic regression analyses were performed adjusting for randomization and baseline risk factors. Whether any potential mediator role for 3HB was direct or indirect was assessed by further adjusting for ketogenesis regulators.

Results

In the matched cohort (n = 96), late-PN versus early-PN increased plasma 3HB throughout PICU days 1–5 (P < 0.0001), maximally on PICU day 2. Also, blood glucose (P < 0.001) and plasma insulin (P < 0.0001), but not glucagon, were affected. In the total cohort (n = 1142 with available plasma), late-PN increased plasma 3HB on PICU day 2 (day 1 for shorter stayers) from (median [IQR]) 0.04 [0.04–0.04] mmol/L to 0.75 [0.04–2.03] mmol/L (P < 0.0001). The 3HB effect of late-PN statistically explained its impact on weaning from mechanical ventilation (P = 0.0002) and on time to live PICU discharge (P = 0.004). Further adjustment for regulators of ketogenesis did not alter these findings.

Conclusion

Withholding early-PN in critically ill children significantly increased plasma 3HB, a direct effect that statistically mediated an important part of its outcome benefit.

Health-related quality of life of children and their parents 2 years after critical illness: pre-planned follow-up of the PEPaNIC international, randomized, controlled trial

Background

Pediatric intensive care unit (PICU) survivors are at risk for prolonged morbidities interfering with daily life. The current study examined parent-reported health-related quality of life (HRQoL) in former critically ill children and parents themselves and aimed to determine whether withholding parenteral nutrition (PN) in the first week of critical illness affected children’s and parents’ HRQoL 2 years later.

Methods

Children who participated in the pediatric early versus late parenteral nutrition in critical illness (PEPaNIC) trial and who were testable 2 years later (n = 1158) were included. Their HRQoL outcomes were compared with 405 matched healthy controls. At PICU admission, children had been randomly assigned to early-PN or late-PN. In the early-PN group, PN was initiated within 24 h after PICU admission. In the late-PN group, PN was withheld for up to 1 week in the PICU. Parents completed the Infant Toddler Quality of Life Questionnaire (ITQOL; age 2–3 years) or the Child Health Questionnaire-Parent Form 50 (CHQ-PF50; age 4–18 years). Besides, they completed the Health Utility Index (HUI) and the Short Form Health Survey (SF-12) regarding their child’s and their own HRQoL, respectively.

Results

For the total age group of 786 post-PICU survivors, parents reported lower scores for almost all HRQoL scales compared to healthy children. Age-specifically, younger critically ill children (2.5 to 3 years old) scored worse for growth and development and older children (4–18 years old) scored worse for role functioning and mental health. Parents’ own mental and physical HRQoL was comparable to that of healthy control parents. No HRQoL differences were found between children in the late-PN and those in the early-PN group.

Conclusions

Parent-reported HRQoL of children 2 years after critical illness was impaired compared with healthy controls. In relation to their child’s HRQoL, parents reported impairments in emotions, personal time, and family activities; however, their own HRQoL was not impaired. Withholding PN in the first week during critical illness had no impact on longer-term HRQoL of the child.

Trial registration

Clinical trials, NCT01536275. Registered 22 February 2012

OR26-02 The Effect on Ketogenesis of Withholding Early Parenteral Nutrition in Critically Ill Children, as a Potential Mediator of the Improved Acute Outcome

Introduction: In adults and children, withholding parenteral nutrition (PN) for 1 week in ICU (late PN), hereby accepting macronutrient deficit early during critical illness, as compared with supplementing insufficient enteral nutrition with PN (early PN), accelerates weaning from mechanical ventilation, reduces infections, and shortens ICU stay^1,2. We hypothesized that these benefits are in part mediated by fasting-induced ketogenesis.

Methods: This is a secondary analysis of the Early versus Late Parenteral Nutrition in the Pediatric ICU (PEPaNIC) RCT (N=1440)². First, for a matched subset of 96 patients with a PICU stay of ≥5 days, daily plasma 3-hydroxybutyrate (3HB) concentrations were determined to identify the time point of maximal effect of late PN versus early PN, if any, on 3HB. Thereafter, for all patients with a plasma sample available on that “maximal effect day” (or last day for shorter stayers), plasma 3HB and insulin concentrations were quantified (N=1142). The independent association between plasma 3HB on that day and outcome was assessed by multivariable Cox proportional hazard analysis for time to live weaning from mechanical ventilation and for time to live PICU discharge and by multivariable logistic regression for incidence of new infection and PICU mortality, adjusted for randomization to late PN versus early PN and baseline risk factors (demographics, diagnosis, illness severity). In a sensitivity analysis, models were further adjusted for key regulators of ketogenesis (plasma insulin, blood glucose, corticosteroids and catecholamines) to assess whether any effect was direct or indirect.

Results: In the matched cohort, late PN increased plasma 3HB as compared with early PN (P<0.0001 for PICU-days 1 to 5), with maximal effect observed on PICU day 2. In the 1142 patients, plasma 3HB concentration on that “maximal effect day” was (mean±SEM) 0.19±0.05 mM in early PN patients and 1.17±0.02 mM in late-PN patients (P<0.0001). Adding these plasma 3HB concentrations to the multivariable models, adjusted for baseline risk factors and randomization, showed that higher plasma 3HB concentrations were independently associated with a higher likelihood of early live weaning from mechanical ventilatory support (P=0.0002) and of early live PICU discharge (P=0.004). As the 3HB concentrations replaced the effect of the randomization, this suggested that the 3HB effect statistically explained these effects of the randomization. Further adjustment for key regulators of ketogenesis did not alter these findings. The effect of late PN versus early PN on plasma 3HB did not explain its impact on infections and was not related to mortality.

Conclusion: Withholding early PN increased plasma 3HB concentrations in critically ill children, a direct effect that mediated an important part of its beneficial impact on recovery.

¹Casaer M. et al, N Engl J Med 2011²Fivez T. et al, N Engl J Med 2016

MON-LB012 Long-Term Developmental Impact of Withholding Parenteral Nutrition in Pediatric-ICU: A 4-Year Follow-Up of the Pepanic Randomized Controlled Trial

Aim: Between 2012-2015, the PEPaNIC randomized controlled trial, which included 1440 critically ill infants and children, showed that withholding parenteral nutrition during the first week in the pediatric intensive care unit (PICU) (late-PN), as compared with initiating supplemental PN early (early-PN), improved PICU outcomes (1) and improved neurocognitive development assessed 2 years later (2). The latter was explained by avoiding early-PN induced adversely altered DNA-methylation of 37 CpG sites (3). As a large number of patients were younger than 1 year of age at randomization and given that assessment of most neurocognitive domains is only possible from 4 years of age onwards, we performed a 4-year follow-up to determine the impact of late-PN versus early-PN on physical, neurocognitive, and emotional/behavioral development. This pre-planned, 4-year follow-up study of the 1440 PEPaNIC patients and of 369 matched healthy children was blinded for treatment allocation (ClinicalTrials.gov-NCT01536275). Methods: Studied clinical outcomes included anthropometrics, health status, parent/caregiver-reported executive functions, and emotional/behavioral problems, and clinical tests for intelligence, visual-motor integration, alertness, motor coordination and memory. Univariable and multivariable linear and logistic regression analyses adjusted for risk factors assessed the impact of late-PN versus early-PN on the outcomes and investigated a potential mediation role of the adversely altered DNA-methylation of 37 CpG sites previously shown to be evoked by late-PN as compared with early-PN (3). Results: Overall, at 4 years follow-up, patients (356 late-PN patients, 328 early-PN patients) could be tested neurocognitively. They revealed worse anthropometric, health status, neurocognitive and emotional/behavioral developmental outcomes than the healthy control children. Outcomes of late-PN patients were never worse than those of early-PN patients. In contrast, late-PN patients had fewer internalizing (P=0.042) and externalizing problems (P=0.046), and fewer total emotional/behavioral problems (P=0.007) than early-PN patients, which were normalized by late-PN. Avoiding the early-PN induced adversely altered DNA-methylation status of the 37 CpG sites statistically explained its impact on the behavioral outcomes. Conclusion: Four years after randomization to late-PN or early-PN in the PICU, late-PN did not show harm, and was found to protect against emotional/behavioral problems, with altered DNA-methylation as a potential biological mediator hereof. These data further support de-implementation of PN-use early during critical illness in infants and children. (1) Fivez et al. N Eng J Med 2016 (2) Verstraete et al. Lancet Respir Med 2019 (3) Guiza et al. Lancet Respir Med 2020 (in press)

SAT-724 Endocrine Disruption by Phthalate Exposure in the Pediatric Intensive Care Unit

Aim: Pediatric intensive care relies on plastic indwelling medical devices softened by phthalates. Phthalates leach into the circulation and concerns about toxicity were raised. Exceeding a certain threshold of di(2-ethylhexyl)phthalate (DEHP) exposure in the pediatric intensive care unit (PICU) has been associated with an attention deficit 4 years later (1). Moreover, DEHP and its metabolites have endocrine disrupting properties. Critically ill children reveal the non-thyroidal illness syndrome (2) and unexplained relatively low cortisol (3). Whether DEHP exposure in PICU has endocrine disruptive effects is unknown. We investigated whether DEHP exposure in the PICU, exceeding the previously identified “toxic” threshold for attention, is independently associated with thyroid- and HPA-axis alterations upon PICU discharge. Methods: In this preplanned secondary analysis of the PEPaNIC RCT (N=1440) (4), plasma DEHP metabolite concentrations (MEHP, 5OH-MEHP, 5cx-MEPP, 5oxo-MEHP) were quantified for all patients with a last PICU day sample (N=920). Minimal DEHP exposure was defined as the product of the total DEHP metabolite concentrations on the last PICU day and duration of PICU stay, with 0.551 µmol/L.days identified as “toxic” threshold (1). Serum TSH, total T4, total T3 and rT3 concentrations were quantified for patients with an available last day sample (N=913). For patients with a last day plasma sample and who did not receive corticosteroids (N=391), plasma ACTH, total cortisol, albumin and CBG concentrations were quantified and free cortisol calculated. Multivariable linear regression analyses, adjusted for baseline risk factors and for duration of PICU stay, assessed whether exceeding the previously determined threshold of toxic DEHP exposure was independently associated with the hormone levels on the last PICU day. Main results: Median total DEHP metabolite concentration was 0.101 (IQR 0.049 - 0.279) µmol/L on the last PICU day. Minimal DEHP exposure was 0.337 (IQR 0.161 - 0.880) µmol/l.days, and 328 patients (35.7%) exceeded the toxic threshold. Exceeding this threshold was independently associated with lower total T4 (P=0.002), total T3 (P=0.02) and total cortisol (P=0.001), and higher rT3 (P=0.01) concentrations on the last PICU day, but not with TSH, ACTH or free cortisol. Conclusion: Critically ill children had DHEP metabolites in plasma upon PICU discharge and more than a third were exposed to toxic levels. Toxic DEHP exposure was an independent contributor to the severity of the non-thyroidal illness phenotype and to lower cortisol upon PICU discharge. Future research should assess whether such endocrine-disruptive impact of DHEP exposure in the PICU plays a role in the long-term developmental legacy of critical illness in children. 1 Verstraete et al Intensive Care Med 2016 2 Jacobs et al Thyroid 2019 3 Jacobs et al Intensive Care Med 2019 4 Fivez et al N Engl J Med 2016

Xylo-oligosaccharides from sugarcane show prebiotic potential in a dynamic computer-controlled in vitro model of the adult human large intestine

The aim of the study was to investigate the prebiotic potential of xylo-oligosaccharides (XOS) from sugarcane in a validated, dynamic, computer-controlled in vitro model of the colon (TIM-2) simulating human adults. In two sets of experiments, each with a different microbiota, 3 different doses of XOS were tested at 1.0 g/day, 1.5 g/day and 3.0 g/day. The in vitro model was run for 72 h, and at the start and subsequently every 24 h samples were taken and analysed for short-chain fatty acids (SCFA) and gut microbiota composition. SCFA were analysed using ion chromatography, whereas microbiota composition was analysed using sequencing of the V3-V4 region of the 16S rRNA gene. XOS showed a similar SCFA production per gram of substrate as the control medium, including butyrate, which is considered to be important for gut health. In both sets of experiments XOS showed a consistent dose-dependent increase in abundance over time of the genus Bifidobacterium, and within that of the species B. adolescentis and an unidentified species (labelled 'sp.1'). The results show the potential prebiotic effect of XOS from sugarcane, by its capacity to generate butyrate and increase the health-beneficial bifidobacteria.

Dynamics and prognostic value of the hypothalamus-pituitary-adrenal axis responses to pediatric critical illness and association with corticosteroid treatment: a prospective observational study

PURPOSE

Increased systemic cortisol availability during adult critical illness is determined by reduced binding-proteins and suppressed breakdown rather than elevated ACTH. Dynamics, drivers and prognostic value of hypercortisolism during pediatric critical illness remain scarcely investigated.

METHODS

This preplanned secondary analysis of the PEPaNIC-RCT (N = 1440), after excluding 420 children treated with corticosteroids before PICU-admission, documented (a) plasma ACTH, (free)cortisol and cortisol-metabolism at PICU-admission, day-3 and last PICU-day, their prognostic value, and impact of withholding early parenteral nutrition (PN), (b) the association between corticosteroid-treatment and these hormones, and (c) the association between corticosteroid-treatment and outcome.

RESULTS

ACTH was normal upon PICU-admission and low thereafter (p ≤ 0.0004). Total and free cortisol were only elevated upon PICU-admission (p ≤ 0.0003) and thereafter became normal despite low binding-proteins (p < 0.0001) and persistently suppressed cortisol-metabolism (p ≤ 0.03). Withholding early-PN did not affect this phenotype. On PICU-day-3, high free cortisol and low ACTH independently predicted worse outcome (p ≤ 0.003). Also, corticosteroid-treatment initiated in PICU, which further suppressed ACTH (p < 0.0001), was independently associated with poor outcomes (earlier live PICU-discharge: p < 0.0001, 90-day mortality: p = 0.02).

CONCLUSION

In critically ill children, systemic cortisol availability is elevated only transiently, much lower than in adults, and not driven by elevated ACTH. Further ACTH lowering by corticosteroid-treatment indicates active feedback inhibition at pituitary level. Beyond PICU-admission-day, low ACTH and high cortisol, and corticosteroid-treatment, predicted poor outcome. This suggests that exogenously increasing cortisol availability during acute critical illness in children may be inappropriate. Future studies on corticosteroid-treatment in critically ill children should plan safety analyses, as harm may be possible.

Probiotic survival during a multi-layered tablet development as tested in a dynamic, computer-controlled in vitro model of the stomach and small intestine (TIM-1)

The aim of the research was to develop a galenical formulation for the combination of the three probiotic strains Lactobacillus gasseri PA 16/8, Bifidobacterium longum SP 07/3 and Bifidobacterium bifidum MF 20/5 that would lead to the presence of a high amount of viable cells in the small intestine, the presumed site of action of these strains. This was tested in a validated, dynamic in vitro model of the stomach and small intestine (TIM‐1), simulating human adults after intake of a meal. Experiments were performed both in the gastric compartment of the model, as well as in the complete system (stomach + small intestine). Survival of the strains in an unformulated probiotic powder after transit through the gastric compartment was 5·3% for the bifidobacteria and 1% for L. gasseri. After transit through the complete gastrointestinal tract, this dropped to 2% for bifidobacteria and 0·1% for Lactobacillus. After several rounds of optimization, an enteric‐coated tablet was developed that increased the delivery of viable cells reaching the small intestine to 72% (gastric survival) for bifidobacteria, and 53% (gastric) for L. gasseri. Also survival in the small intestine increased by about an order of magnitude. The final galenical formulation was tested in two applications: adults and elderly, both of which have their own physiological parameters. These experiments corroborated the results obtained in the development phase of the project. In conclusion, the developed enteric coating led to a 20‐ to 40‐fold increase in the delivery of viable cells to the small intestine.

Significance and Impact of the Study

Predictive GI in vitro models are very helpful and reliable tools for the development of new galenical formula containing probiotics, and in the current example helped to deliver >10‐fold higher numbers of viable cells to the small intestine, presumably leading to improved functionality of the strains.

OR17-1 Changes in the Hypothalamic-Pituitary-Adrenal Axis during Pediatric Critical Illness

Critical illness in adults is hallmarked by prolonged hypercortisolism and a rapid decrease in ACTH. The high cortisol is explained by reduced cortisol breakdown and a decrease in cortisol binding proteins, rather than by adrenal production. In critically ill children, the evolution of the changes in the HPA axis and underlying mechanisms remain to be studied. Also, the impact hereon of nutritional management is unknown. In the PEPaNIC RCT, accepting low macronutrient intake up to day 8 in the pediatric intensive care unit (PICU) by withholding early supplemental parenteral nutrition (PN) accelerated recovery as compared with initiating supplemental PN early. In this preplanned secondary analysis of the PEPaNIC RCT, we assessed the changes over time in the HPA axis and their prognostic value during critical illness in children and investigated the impact on these changes of withholding early PN. We quantified plasma ACTH, total cortisol, CBG and albumin and calculated free cortisol upon PICU admission, day 3 and last PICU day for 223 short-stay (<3 days) and 309 long-stay patients (≥3 days) who did not receive corticosteroids before sampling, in comparison with 64 matched healthy children. Upon admission, ACTH was elevated in short-stay patients (P=0.02) and comparable with healthy children in long-stay patients (P=0.75), whereas total and free cortisol were elevated in both groups (P<0.0001). In short-stay patients, ACTH became subnormal on the last day (P<0.0001). Also total and free cortisol decreased, but remained higher than in healthy children (P=0.003-0.005). In long-stay patients, ACTH decreased towards day 3 (P<0.0001) and remained low on the last day (P<0.0001), whereas total and free cortisol were normal on day 3 (P=0.37-0.62) and on the last day (P=0.30-0.74). CBG and albumin were low throughout PICU stay in both groups. The rapid decrease in cortisol over time in PICU likely excludes negative feedback by cortisol on pituitary ACTH secretion as cause of the decrease in ACTH. In multivariable analysis, the decrease in ACTH was also not associated with drugs commonly used in PICU, that have been suggested to affect the HPA axis in adults. High total and free cortisol upon admission were associated with 90-day mortality and prolonged length of stay in univariable analysis. This association disappeared when adjusting for baseline risk factors. Withholding early PN did not affect the changes in the HPA axis from admission to day 3 or to last day for short-stay patients. In conclusion, the time course of the changes in the HPA axis during critical illness in children differs from that in adults, with a rapid normalization of cortisol together with a decrease in ACTH over time. Further investigation of the mechanism underlying this ACTH decrease is warranted, since it might be iatrogenic or related to a possibly more immature central secretion during critical illness in children as compared with adults.

Non-Thyroidal Illness Syndrome in Critically Ill Children: Prognostic Value and Impact of Nutritional Management

INTRODUCTION

Non-thyroidal illness (NTI), which occurs with fasting and in response to illness, is characterized by thyroid hormone inactivation with low triiodothyronine (T3) and high reverse T3 (rT3), followed by suppressed thyrotropin (TSH). Withholding supplemental parenteral nutrition early in pediatric critical illness (late-PN), thus accepting low/no macronutrient intake up to day 8 in the pediatric intensive care unit (PICU), accelerated recovery compared to initiating supplemental parenteral nutrition early (early-PN). Whether NTI is harmful or beneficial in pediatric critical illness and how it is affected by a macronutrient deficit remains unclear. This study investigated the prognostic value of NTI, the impact of late-PN on NTI, and whether such impact explains or counteracts the outcome benefit of late-PN in critically ill children.

METHODS

This preplanned secondary analysis of the Early versus Late Parenteral Nutrition in the Pediatric Intensive Care Unit randomized controlled trial quantified serum TSH, total thyroxine (T4), T3, and rT3 concentrations in 982 patients upon PICU admission versus 64 matched healthy children and in 772 propensity score-matched early-PN and late-PN patients upon admission and at day 3 or last PICU day for shorter PICU stay. Associations between thyroid hormone concentrations upon admission and outcome, as well as impact of late-PN on NTI in relation with outcome, were assessed with univariable analyses and multivariable logistic regression, linear regression, or Cox proportional hazard analysis, adjusted for baseline risk factors.

RESULTS

Upon PICU admission, critically ill children revealed lower TSH, T4, T3, and T3/rT3 and higher rT3 than healthy children (p < 0.0001). A more pronounced NTI upon admission, with low T4, T3, and T3/rT3 and high rT3 was associated with higher mortality and morbidity. Late-PN further reduced T4, T3, and T3/rT3 and increased rT3 (p ≤ 0.001). Statistically, the further lowering of T4 by late-PN reduced the outcome benefit (p < 0.0001), whereas the further lowering of T3/rT3 explained part of the outcome benefit of late-PN (p ≤ 0.004). This effect was greater for infants than for older children.

CONCLUSION

In critically ill children, the peripheral inactivation of thyroid hormone, characterized by a decrease in T3/rT3, which is further accentuated by low/no macronutrient intake, appears beneficial. In contrast, the central component of NTI attributable to suppressed TSH, evidenced by the decrease in T4, seems to be a harmful response to critical illness. Whether treating the central component with TSH releasing hormone infusion in the PICU is beneficial requires further investigation.

Spores of Bacillus coagulans GBI-30, 6086 show high germination, survival and enzyme activity in a dynamic, computer-controlled in vitro model of the gastrointestinal tract

The aim of this study was to assess the germination, survival and metabolic activity of the probiotic Bacillus coagulans GBI-30, 6086 [GanedenBC³⁰] (BC30) in a dynamic, computer controlled in vitro model of the gastrointestinal (GI) tract, simulating human adults. Experiments were performed in the presence of a meal to maximise germination, due to the presence of germination-triggers. Both an upper GI tract (stomach and small intestine; TIM-1) and a colon model (TIM-2) were used, where material exiting TIM-1 was added to TIM-2. Spores of BC30 were introduced in the gastric compartment of TIM-1 and samples were taken immediately after the pylorus. Moreover, for 6 h, every hour the ileal efflux was collected and a subsample was plated for viable counts (spores and germinated cells). The remainder of the sample was fed to TIM-2, and after 24 h another sample was taken and tested for viable counts. In addition, samples were taken from the dialysates of the model and analysed using LC-MS/MS to determine bacterial metabolites and digestion products. Survival after transit through the gastric compartment was high (97%) and most cells were still in the spore form (76%). Survival after transit through TIM-1 was on average 51%, meaning that on average half of the orally provided spores was found back as cfu on the agar plates. Of these on average 93% were germinated cells and only 7% were spores. 24 h after the start of the experiments germination had increased in TIM-2 to 97% vegetative cells, and only 3% spores. No further loss of viability was observed in TIM-2. In terms of metabolic activity, increased levels of amino acids, dipeptides and citric acid cycle metabolites were found compared to experiments in the absence of BC30. In conclusion, BC30 spores germinate to a large extent (>90%) in the presence of germination triggers in the small intestine in a model that closely mimics the physiological conditions of human adults. Of the oral dose, as much as half of the cells survived transit through the upper GI tract, and based on the metabolite profile, these cells were metabolically active. Either these cells or the enzymes released from the dead cells aided in digestion of the meal. These insights help explain some of the observations in previous experiments, and support the understanding of the mechanism of action of the probiotic BC30.

Microencapsulation increases survival of the probiotic Lactobacillus plantarum IS-10506, but not Enterococcus faecium IS-27526 in a dynamic, computer-controlled in vitro model of the upper gastrointestinal tract

AIM

To test the effect of microencapsulation on the survival of two probiotic strains isolated from Dadih, Indonesian fermented buffalo milk, in a dynamic, computer-controlled in vitro model of the upper gastrointestinal (GI) tract (TIM-1), simulating human adults.

METHODS AND RESULTS

Free or microencapsulated probiotics, Lactobacillus plantarum IS-10506 or Enterococcus faecium IS-27526, resuspended in milk were studied for survival in the complete TIM-1 system (stomach + small intestine) or in the gastric compartment of TIM-1 only. Hourly samples collected after the ileal-caecal valve or after the pylorus were plated on MRS agar (for Lactobacillus) or S&B agar (for Enterococcus). Survival of the free cells after transit through the complete TIM-1 system was on average for the E. faecium and L. plantarum 15·0 and 18·5% respectively. Survival of the microencapsulated E. faecium and L. plantarum was 15·7 and 84·5% respectively. The free cells were further assessed in only the gastric compartment of TIM-1. E. faecium and L. plantarum showed an average survival of 39 and 32%, respectively, after gastric passage.

CONCLUSION

There is similar sensitivity to gastric acid as well as survival after complete upper GI tract transit of free cells, but microencapsulation only protected L. plantarum.

SIGNIFICANCE AND IMPACT OF STUDY

Survival of microencapsulated L. plantarum IS-10506 is increased compared to free cells in a validated in vitro model of the upper GI tract. It increases its use as an ingredient of functional foods.

Effect of early supplemental parenteral nutrition in the paediatric ICU: a preplanned observational study of post-randomisation treatments in the PEPaNIC trial

BACKGROUND

Large randomised controlled trials have shown that early supplemental parenteral nutrition in patients admitted to adult and paediatric intensive care units (PICUs) is harmful. Overdosing of energy with too little protein was suggested as a potential reason for this. This study analysed which macronutrient was associated with harm caused by early supplemental parenteral nutrition in the Paediatric Early versus Late Parenteral Nutrition In Critical Illness (PEPaNIC) randomised trial.

METHODS

Patients in the initial randomised controlled trial were randomly assigned to receive suppplemental parenteral nutrition (PN) within 24 h of PICU admission (early PN) or to receive such PN after 1 week (late PN) when enteral nutrition was insufficient. In this post-randomisation, observational study, doses of glucose, lipids, and aminoacids administered during the first 7 days of PICU stay were expressed as % of reference doses from published clinical guidelines for age and weight. Independent associations between average macronutrient doses up to each of the first 7 days and likelihood of acquiring an infection in the PICU, of earlier live weaning from mechanical ventilation, and of earlier live PICU discharge were investigated using multivariable Cox proportional hazard analyses. The three macronutrients were included in the analysis simultaneously and baseline risk factors were adjusted for.

FINDINGS

From June 18, 2012, to July 27, 2015, 7519 children aged between newborn and 17 years were assessed for eligibility. 6079 patients were excluded, and 1440 children were randomly assigned to receive either early PN (n=723) or late PN (n=717). With increasing doses of aminoacids, the likelihood of acquiring a new infection was higher (adjusted hazard ratios [HRs] per 10% increase between 1·043-1·134 for days 1-5, p≤0·029), while the likelihood of earlier live weaning from mechanical ventilation was lower (HRs 0·950-0·975 days 3-7, p≤0·045), and the likelihood of earlier live PICU discharge was lower (HRs 0·943-0·972 days 1-7, p≤0·030). By contrast, more glucose during the first 3 days of PICU stay was independently associated with fewer infections (HRs 0·870-0·913, p≤0·036), whereas more lipids was independently associated with earlier PICU discharge (HRs 1·027-1·050, p≤0·043 days 4-7). Risk of harm with aminoacids was also shown for low doses.

INTERPRETATION

These associations suggest that early administration of aminoacids, but not glucose or lipids, could explain harm caused by early supplemental parenteral nutrition in critically ill children.

FUNDING

Flemish Agency for Innovation through Science and Technology; UZLeuven Clinical Research Fund; Research Foundation Flanders; Methusalem Programme Flemish Government; European Research Council; Fonds-NutsOhra; Erasmus-MC Research Grant; Erasmus Trustfonds.

Red Blood Cell Distribution Width and the Platelet Count in Iron-deficient Children Aged 0.5-3 Years

Early detection of iron deficiency (ID) and iron deficiency anemia (IDA) in young children is important to prevent impaired neurodevelopment. Unfortunately, many biomarkers of ID are influenced by infection, thus limiting their usefulness. The aim of this study was to investigate the value of red blood cell distribution width (RDW) and the platelet count for detecting ID(A) among otherwise healthy children. A multicenter prospective observational study was conducted in the Netherlands to investigate the prevalence of ID(A) in 400 healthy children aged 0.5-3 years. ID was defined as serum ferritin (SF) <12 μg/L in the absence of infection (C-reactive protein [CRP] <5 mg/L) and IDA as hemoglobin <110 g/L combined with ID. RDW (%) and the platelet count were determined in the complete blood cell count. RDW was inversely correlated with SF and not associated with CRP. Calculated cutoff values for RDW to detect ID and IDA gave a relatively low sensitivity (53.1% and 57.1%, respectively) and specificity (64.7% and 69.9%, respectively). Anemic children with a RDW >14.3% had a 2.7 higher odds (95% confidence interval [CI]: 1.2-6.3) to be iron deficient, compared with anemic children with a RDW <14.3%. The platelet count showed a large range in both ID and non-ID children. In conclusion, RDW can be helpful for identifying ID as the cause of anemia in 0.5- to 3-year-old children, but not as primary biomarker of ID(A). RDW values are not influenced by the presence of infection. There appears to be no role for the platelet count in diagnosing ID(A) in this group of children.

Early versus Late Parenteral Nutrition in Critically Ill Children

BACKGROUND

Recent trials have questioned the benefit of early parenteral nutrition in adults. The effect of early parenteral nutrition on clinical outcomes in critically ill children is unclear.

METHODS

We conducted a multicenter, randomized, controlled trial involving 1440 critically ill children to investigate whether withholding parenteral nutrition for 1 week (i.e., providing late parenteral nutrition) in the pediatric intensive care unit (ICU) is clinically superior to providing early parenteral nutrition. Fluid loading was similar in the two groups. The two primary end points were new infection acquired during the ICU stay and the adjusted duration of ICU dependency, as assessed by the number of days in the ICU and as time to discharge alive from ICU. For the 723 patients receiving early parenteral nutrition, parenteral nutrition was initiated within 24 hours after ICU admission, whereas for the 717 patients receiving late parenteral nutrition, parenteral nutrition was not provided until the morning of the 8th day in the ICU. In both groups, enteral nutrition was attempted early and intravenous micronutrients were provided.

RESULTS

Although mortality was similar in the two groups, the percentage of patients with a new infection was 10.7% in the group receiving late parenteral nutrition, as compared with 18.5% in the group receiving early parenteral nutrition (adjusted odds ratio, 0.48; 95% confidence interval [CI], 0.35 to 0.66). The mean (±SE) duration of ICU stay was 6.5±0.4 days in the group receiving late parenteral nutrition, as compared with 9.2±0.8 days in the group receiving early parenteral nutrition; there was also a higher likelihood of an earlier live discharge from the ICU at any time in the late-parenteral-nutrition group (adjusted hazard ratio, 1.23; 95% CI, 1.11 to 1.37). Late parenteral nutrition was associated with a shorter duration of mechanical ventilatory support than was early parenteral nutrition (P=0.001), as well as a smaller proportion of patients receiving renal-replacement therapy (P=0.04) and a shorter duration of hospital stay (P=0.001). Late parenteral nutrition was also associated with lower plasma levels of γ-glutamyltransferase and alkaline phosphatase than was early parenteral nutrition (P=0.001 and P=0.04, respectively), as well as higher levels of bilirubin (P=0.004) and C-reactive protein (P=0.006).

CONCLUSIONS

In critically ill children, withholding parenteral nutrition for 1 week in the ICU was clinically superior to providing early parenteral nutrition. (Funded by the Flemish Agency for Innovation through Science and Technology and others; ClinicalTrials.gov number, NCT01536275.).

Optimal nutrition in the paediatric ICU

PURPOSE OF REVIEW

This article describes the current best available evidence on optimal nutrition in the paediatric intensive care based on different levels of outcome, which can be divided in surrogate and hard clinical outcome parameters.

RECENT FINDINGS

Undernutrition is associated with increased morbidity and mortality, whereas in specific cohorts of critically ill children, such as those with burn injury, obesity is associated with more complications, longer length of stay, and decreased likelihood of survival. There is a relation with adequacy of delivery of enteral nutrition and the amount of protein on length of hospital stay, neurological status, and mortality. Studies relating organ function, other than skin healing after thermal injury, with the nutritional status are scarce. There is also a scarcity of data concerning long-term follow-up and health economics.

SUMMARY

Until now, there are no randomized controlled trials which have investigated a causal relation between different feeding regimens on the nutritional status and short and long-term outcome. As a result current optimal nutritional strategies are based on small trials with surrogate outcome parameters. Prospective randomized studies are needed with nutritional and/or metabolic interventions to come to an optimal feeding strategy for critically ill children.

Evidence for the use of parenteral nutrition in the pediatric intensive care unit

BACKGROUND AND AIMS

During hospitalization in a pediatric intensive care unit (PICU), critically ill children are fed artificially. Administered via the preferred enteral route, caloric targets are often not reached. Hence, parenteral nutrition is given to this patient population. In this review we analyzed the available evidence from randomized controlled trials (RCTs) that supports the use of parenteral nutrition in children during critical illness.

METHODS

A search strategy in Ovid MEDLINE and Ovid EMBASE was created and trial registries were screened to identify the relevant RCTs. Studies were included if they were randomized controlled trials, involved pediatric patients admitted to PICU, and compared different dosing/compositions of parenteral nutrition. Descriptive studies and reviews were excluded.

RESULTS

Of the 584 articles identified by the search strategy, only 114 articles were retained after title screening. Further abstract and full text screening identified 6 small RCTs that compared two dosing/composition strategies of parenteral nutrition. These trials reported differences in surrogate endpoints without an effect on hard clinical endpoints. The RCTs observed improvements in these surrogate endpoints with the use of more calories or when parenteral glutamine or fish oil was added.

CONCLUSIONS

The few RCTs suggest that surrogate endpoints can be affected by providing parenteral nutrition to critically ill children, but the studies were not statistically powered to draw meaningful clinical conclusions. Large RCTs with clinically relevant outcome measures are urgently needed to support the current nutritional guidelines that advise the use of parenteral nutrition in the PICU.

Impact of withholding early parenteral nutrition completing enteral nutrition in pediatric critically ill patients (PEPaNIC trial): study protocol for a randomized controlled trial

Background

The state-of-the-art nutrition used for critically ill children is based essentially on expert opinion and extrapolations from adult studies or on studies in non-critically ill children. In critically ill adults, withholding parenteral nutrition (PN) during the first week in ICU improved outcome, as compared with early supplementation of insufficient enteral nutrition (EN) with PN. We hypothesized that withholding PN in children early during critical illness reduces the incidence of new infections and accelerates recovery.

Methods/Design

The Pediatric Early versus Late Parenteral Nutrition in Intensive Care Unit (PEPaNIC) study is an investigator-initiated, international, multicenter, randomized controlled trial (RCT) in three tertiary referral pediatric intensive care units (PICUs) in three countries on two continents. This study compares early versus late initiation of PN when EN fails to reach preset caloric targets in critically ill children. In the early-PN (control, standard of care) group, PN comprising glucose, lipids and amino acids is administered within the first days to reach the caloric target. In the late-PN (intervention) group, PN completing EN is only initiated beyond PICU-day 7, when EN fails. For both study groups, an early EN protocol is applied and micronutrients are administered intravenously. The primary assessor-blinded outcome measures are the incidence of new infections during PICU-stay and the duration of intensive care dependency. The sample size (n = 1,440, 720 per arm) was determined in order to detect a 5% absolute reduction in PICU infections, with at least 80% 1-tailed power (70% 2-tailed) and an alpha error rate of 5%. Based on the actual incidence of new PICU infections in the control group, the required sample size was confirmed at the time of an a priori- planned interim-analysis focusing on the incidence of new infections in the control group only.

Discussion

Clinical evidence in favor of early administration of PN in critically ill children is currently lacking, despite potential benefit but also known side effects. This large international RCT will help physicians to gain more insight in the clinical effects of omitting PN during the first week of critical illness in children.

Trial registration

ClinicalTrials.gov: NCT01536275 on 16 February 2012.

ADAM10 and ADAM17 have opposite roles during sprouting angiogenesis

During angiogenesis, endothelial tip cells start sprouting and express delta-like 4 (DLL4) downstream of vascular endothelial growth factor (VEGF). DLL4 subsequently activates Notch in the adjacent stalk cells suppressing sprouting. VEGF also activates A disintegrin and metalloproteases (ADAMs) that induce Notch ectodomain shedding. Although two major ADAMs, i.e. ADAM10 and ADAM17, have been implicated in Notch-signalling activation, their apparent different roles in angiogenesis have not been fully understood yet. The objective of this study was to determine the roles of ADAM10 and ADAM17 activity in angiogenesis. In mouse retinas, ADAM10 or γ-secretase inhibition induced vascular sprouting and density in vivo, whereas attenuation of both ADAM10 and ADAM17 activity produced the opposite phenotype. Retinal blood vessel analysis in ADAM17 hypomorphic mice confirmed the requirement for ADAM17 activity in angiogenesis. However, ADAM17 inhibition did not phenocopy blood vessel increase by Notch blockage. These observations suggest that ADAM17 regulates other fundamental players during angiogenesis besides Notch, which were not affected by ADAM10. By means of an angiogenesis proteome assay, we found that ADAM17 inhibition induced the expression of a naturally occurring inhibitor of angiogenesis Thrombospondin 1 (TSP1), whereas ADAM10 inhibition did not. Accordingly, ADAM17 overexpression downregulated TSP1 expression, and the TSP1 inhibitor LSKL rescued angiogenesis in the tube formation assay downstream of VEGF in the presence of ADAM17 inhibition. Finally, genetic and pharmacological ADAM17 blockade resulted in increased TSP1 expression in mouse retina. Altogether, our results show that ADAM10 and ADAM17 have opposite effects on sprouting angiogenesis that may be unrelated to Notch signalling and involves differentially expressed anti-angiogenic proteins such as TSP1.

Parenteral amino acid intakes in critically ill children: a matter of convenience

BACKGROUND

Parenteral and enteral amino acid requirements for nutrition balance and function have not been defined in critically ill children or adults. In addition to playing a role in protein synthesis, amino acids trigger signaling cascades that regulate various aspects of fuel and energy metabolism and serve as precursors for important substrates. Amino acids can also be toxic. In this study, parenteral intakes of essential and nonessential amino acids (EAAs and NEAAs) supplied to critically ill children were assessed as an initial step for further studies aimed at establishing parenteral amino acid requirements.

METHODS

A retrospective review was conducted to assess intakes of parenteral amino acid for 116 critically ill children, and these intakes were compared with EAA intakes recommended by the Institute of Medicine. Because there are no recommended intakes for NEAA, NEAA intakes were compared with mixed muscle protein content in the older children and breast milk amino acid content in the infants.

RESULTS

Parenteral EAAs were provided in amounts that exceeded recommended intakes for healthy children, except for phenylalanine and methionine, which although excessive, were given in less generous amounts. NEAAs were supplied in lower or higher amounts than the content of mixed muscle proteins or breast milk. Parenteral amino acid formulas are limited in taurine, glutamine, and asparagine despite the fact that inflammatory/immune proteins are rich in these amino acids.

CONCLUSIONS

Amino acid composition of parenteral formulas is variable and lacks scientific support. Parenteral amino acid intakes should be based on measured requirements to maintain nutrition and functional balance and on knowledge of toxicity.

Ontogeny of methionine utilization and splanchnic uptake in critically ill children

To determine the rates of methionine splanchnic uptake and utilization in critically ill pediatric patients we used two kinetic models: the plasma methionine enrichment and the "intracellular" homocysteine enrichment. Twenty four patients, eight infants, eight children, and eight adolescents, were studied. They received simultaneous, primed, constant, intravenous infusions of l-[(2)H(3)]methylmethionine and enteral l-[1-(13)C]methionine. The ratio of [(13)C]homocysteine to [(13)C]methionine enrichment was 1.0 ± 0.15, 0.80 ± 0.20, and 0.66 ± 0.10, respectively, for the infants, children, and adolescents, and it was different between the infants and adolescents (P < 0.01). Methionine splanchnic uptake was 63, 45, and 36%, respectively, in the infants, children, and adolescents, and it was higher (P < 0.01) in the infants compared with the adolescents. The infants utilized 73% of methionine flux for nonoxidative disposal, while 27% was used for transulfuration (P < 0.001). Conversely, in the adolescents, 40% was utilized for nonoxidative disposal, while 60% was used for transulfuration. There is ontogeny on the rates of methionine splanchnic uptake and on the fate of methionine utilization in critically ill children, with greater methionine utilization for synthesis of proteins and methionine-derived compounds (P < 0.01) and decreased transulfuration rates in the infants (P < 0.01), while the opposite was observed in the adolescents. The plasma model underestimated methionine kinetics in children and adolescents but not in the infants, suggesting lesser dilution and greater compartmentation of methionine metabolism in the infant population. All patients were in negative methionine balance, indicating that the current enteral nutritional support is inadequate in these patients.