Increased protein-energy intake promotes anabolism in critically ill infants with viral bronchiolitis: a double-blind randomised controlled trial

Bronchiolitis: evidence-based management in high-risk infants in the intensive care setting

AIM

Systematically review the management of infants with severe bronchiolitis in a paediatric intensive care unit (PICU) setting with a focus on high-risk infants to identify gaps in evidence-based knowledge.

METHODS

This systematic review utilised Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) to examine the literature on the PICU management of bronchiolitis in infants <24 months old. Three databases, Embase, PubMed and Medline, were searched and higher levels of evidence I, II and III were included.

RESULTS

There were 455 papers reviewed and 26 met the inclusion criteria. Furthermore, 19 of these studied respiratory interventions such as positive airway pressure and oxygen delivery. The remaining 7 examined: erythropoietin, caffeine, dexamethasone, protein supplementation, ribavirin, respiratory syncytial virus immune globulin, or diuretic therapy. Of the 26 studies, 20 excluded infants with high-risk conditions. Therapies showing favourable outcomes included Heliox, prophylactic dexamethasone pre-extubation, protein supplementation, and diuretic use.

CONCLUSIONS

Clinical trials for bronchiolitis management frequently exclude high-risk children. Innovative study design in the future may improve access to clinical trials for the management of bronchiolitis in high-risk infants in a PICU setting.

IMPACT

Clinical trials for bronchiolitis management frequently exclude high-risk children. We review the evidence base for the management of an under-investigated patient demographic in the setting of acute bronchiolitis. Randomised controlled trials are needed to determine the efficacy of management strategies for bronchiolitis in high-risk infants in a paediatric intensive care setting.

"Feed a Cold, Starve a Fever?" A Review of Nutritional Strategies in the Setting of Bacterial Versus Viral Infections

PURPOSE OF REVIEW

Some data, mostly originally derived from animal studies, suggest that low glucose intake is protective in bacterial sepsis but detrimental in overwhelming viral infections. This has been interpreted into a broad belief that different forms of sepsis may potentially require different nutritional management strategies. There are a few mechanistic differences between the host interactions with virus and bacteria which can explain why there may be opposing responses to macronutrient and micronutrient during the infected state. Here, we aim to review relevant evidence on the mechanisms and pathophysiology of nutritional management strategies in various infectious syndromes and summarize their clinical implications.

RECENT FINDINGS

Newer literature - in the context of the SARS-CoV-19 pandemic - offers some insight to viral infections. There is still limited clinically applicable data during infection that clearly delineate the role of nutrition during an active viral vs bacterial infections. Based on contrasting findings in different models of viruses and bacteria, the macronutrient and micronutrient needs may depend more on specific infectious organisms that may not be generalizable as bacterial versus viral. Overall, the metabolic effects of sepsis are context dependent, and various host-specific (e.g., age, baseline nutritional status, immune status, comorbidities) and illness variables (phase, duration, and severity of illness) play a significant role in determining the outcome besides pathogen-specific (virus or bacterial or fungi and combined infections) factors. Microbe therapy (probiotics and prebiotics) seems to have therapeutic potential in both viral and bacterial infected states, and this seems like a promising area for further practical research.

A Quality Initiative to Prioritize Enteral Feeding in Bronchiolitis

Introduction

Recent studies have identified enteral feeding as a safe alternative to intravenous fluid hydration for inpatients with bronchiolitis receiving respiratory support. Specifically, it can improve vital signs, shorten time on high-flow nasal cannula, and is associated with reduced length of stay. We aimed to increase the percentage of patients receiving enteral feeding on admission with mild-to-moderate bronchiolitis, including those on high-flow nasal cannula, from 83% to 95% within 6 months.

Methods

A multidisciplinary quality improvement team identified key drivers preventing enteral feeding as lack of standardization, perception of aspiration risk, and lack of familiarity with feeding orders. PDSA cycles focused on developing and implementing a bronchiolitis clinical practice pathway with an embedded guideline and order set as decision support to prioritize enteral feeding. Additionally, educational sessions were provided for trainees and attendings who were impacted by this pathway.

Results

Following interventions, initiation of enteral feeding increased (83%-96%). Additionally, intravenous line placement decreased (37%-12%) with a mirrored increase in nasogastric tube placement (4%-21%). This was associated with a shorter overall length of stay and no increased transfer rate to intensive care.

Conclusions

Using quality improvement methodology to standardize enteral feeding and hydration increased the initiation rate of enteral feeding in patients admitted with bronchiolitis. These changes were seen immediately after the implementation of the clinical pathway and sustained throughout the bronchiolitis season.

Effect of three enteral diets with different protein contents on protein metabolism in critically ill infants: a randomized controlled trial

INTRODUCTION

The optimal intake to improve protein metabolism without producing adverse effects in seriously ill infants has yet to be established. The aim of our study was to analyse whether an increased protein intake delivered through enteral nutrition would be associated with an improvement in nitrogen balance and serum protein levels in critically ill infants.

METHODS

We conducted a multicentre, prospective randomized controlled trial (December 2016-June 2019). The sample consisted of critically ill infants receiving enteral nutrition assigned randomly to 3 protein content groups: standard diet (1.7 g/dL), protein-enriched diet (2.7 g/dL) and high protein-enriched diet (5.1 g/dL). Blood and urine tests were performed, and we assessed nitrogen balance at baseline and at 3-5 days of the diet. We analysed variations in nitrogen balance and serum protein levels (total protein, albumin, transferrin, prealbumin, and retinol-binding protein) throughout the study period.

RESULTS

Ninety-nine infants (33 per group) completed the study. We did not find any differences were between groups in demographic characteristics, severity scores or prescribed medications, except for corticosteroids, administered in a higher proportion of patients in the third group. We observed significant increases in prealbumin and retinol-binding protein levels in patients receiving the protein-enriched and high protein-enriched diets at 3-5 days compared to baseline. The nitrogen balance increased in all groups, but the differences were not significant in the high protein-enriched group. There were no differences in gastrointestinal tolerance. Patients fed high protein-enriched formula had higher levels of serum urea, with a higher incidence of hyperuraemia in this group.

CONCLUSION

Enteral administration of higher amounts of protein improves serum protein levels in critically ill children. A protein intake of 2.2 g/kg/day is generally safe and well tolerated, whereas an intake of 3.4 g/kg/day may produce hyperuraemia in some patients.

Clinical practice guidelines: management of severe bronchiolitis in infants under 12 months old admitted to a pediatric critical care unit

PURPOSE

We present guidelines for the management of infants under 12 months of age with severe bronchiolitis with the aim of creating a series of pragmatic recommendations for a patient subgroup that is poorly individualized in national and international guidelines.

METHODS

Twenty-five French-speaking experts, all members of the Groupe Francophone de Réanimation et Urgence Pédiatriques (French-speaking group of paediatric intensive and emergency care; GFRUP) (Algeria, Belgium, Canada, France, Switzerland), collaborated from 2021 to 2022 through teleconferences and face-to-face meetings. The guidelines cover five areas: (1) criteria for admission to a pediatric critical care unit, (2) environment and monitoring, (3) feeding and hydration, (4) ventilatory support and (5) adjuvant therapies. The questions were written in the Patient-Intervention-Comparison-Outcome (PICO) format. An extensive Anglophone and Francophone literature search indexed in the MEDLINE database via PubMed, Web of Science, Cochrane and Embase was performed using pre-established keywords. The texts were analyzed and classified according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. When this method did not apply, an expert opinion was given. Each of these recommendations was voted on by all the experts according to the Delphi methodology.

RESULTS

This group proposes 40 recommendations. The GRADE methodology could be applied for 17 of them (3 strong, 14 conditional) and an expert opinion was given for the remaining 23. All received strong approval during the first round of voting.

CONCLUSION

These guidelines cover the different aspects in the management of severe bronchiolitis in infants admitted to pediatric critical care units. Compared to the different ways to manage patients with severe bronchiolitis described in the literature, our original work proposes an overall less invasive approach in terms of monitoring and treatment.

Energy- and protein-enriched formula improves weight gain in infants with malnutrition due to cardiac and non-cardiac etiologies

Background

We aimed to assess safety, tolerability, and improvement in weight gain with an energy‐ and protein‐enriched formula (EPEF) in infants with poor growth.

Methods

Infants aged 1–8 months with poor growth received EPEF for 16 weeks. Our primary objective was improvement in weight as measured by change in weight‐for‐age z‐score (WAZ) and weight gain velocity (grams per day) ≥ median for age. Secondary objectives included improvement in other anthropometric z‐scores, formula tolerance, and safety.

Results

Twenty‐six patients with poor growth due to congenital heart disease (n = 15), other organic causes (n = 9), and nonorganic causes (n = 2) completed the study per protocol. Mean daily energy intake was 123 ± 32 kilocalories per kilogram of body weight, with >90% of energy coming from EPEF. Weight gain velocity exceeded the median for 83% (20 of 24) and 67% (16 of 24) of infants at ≥1 time point and for the overall study period, respectively. Mean ± SD WAZ improved from −2.92 ± 1.04 at baseline to −2.01 ± 1.12 at 16 weeks (P = 0.0001). Z‐scores for weight‐for‐length and head circumference (P = 0.0001) and for length‐for‐age (P = 0.003) improved significantly at 16 weeks. Compared with baseline, stool consistency was different at 2, 4, and 16 weeks (P < 0.05). There were no significant differences in vomiting, fussiness, or daily number of stools while there was a decrease or no change in spit‐up, flatulence, crying, or gassiness.

Conclusion

EPEF is safe, well tolerated, and improves weight gain in infants with poor growth.

Citrulline, Biomarker of Enterocyte Functional Mass and Dietary Supplement. Metabolism, Transport, and Current Evidence for Clinical Use

L-Citrulline is a non-essential but still important amino acid that is released from enterocytes. Because plasma levels are reduced in case of impaired intestinal function, it has become a biomarker to monitor intestinal integrity. Moreover, oxidative stress induces protein citrullination, and antibodies against anti-citrullinated proteins are useful to monitor rheumatoid diseases. Citrullinated histones, however, may even predict a worse outcome in cancer patients. Supplementation of citrulline is better tolerated compared to arginine and might be useful to slightly improve muscle strength or protein balance. The following article shall provide an overview of L-citrulline properties and functions, as well as the current evidence for its use as a biomarker or as a therapeutic supplement.

Comprehensive metabolic amino acid flux analysis in critically ill patients

Amino acid (AA) metabolism is severely disturbed in critically ill ICU patients. To be able to make a more scientifically based decision on the type of protein or AA nutrition to deliver in ICU patients, comprehensive AA phenotyping with measurements of plasma concentrations and whole body production (WBP) is needed. Therefore, we studied ICU patients and matched control subjects using a novel pulse isotope method to obtain in-depth metabolic analysis. In 51 critically ill ICU patients (SOFA~6.6) and 49 healthy controls, we measured REE and body composition/phase-angle using BIA. In the postabsorptive state, we collected arterial (ized) blood for CRP and AA. Then, we administered an 8 mL solution containing 18 stable AA tracers as a pulse and calculated WBP. Enrichments: LC-MS/MS and statistics: t-test, ANCOVA. Compared to healthy, critically ill ICU patients had lower phase-angle (p < 0.00001), and higher CRP (p < 0.0001). Most AA concentrations were lower in ICU patients (p < 0.0001), except tau-methylhistidine and phenylalanine. WBP of most AA were significantly (p < 0.0001) higher with increases in glutamate (160%), glutamine (46%), and essential AA. Remarkably, net protein breakdown was lower. There were only weak relationships between AA concentrations and WBP. Critically ill ICU patients (SOFA 8-16) had lower values for phase angle (p = 0.0005) and small reductions of most plasma AA concentrations, but higher tau-methylhistidine (p = 0.0223) and hydroxyproline (p = 0.0028). Remarkably, the WBP of glutamate and glutamine were lower (p < 0.05), as was their clearance, but WBP of tau-methylhistidine (p = 0.0215) and hydroxyproline (p = 0.0028) were higher. Our study in critically ill ICU patients shows that comprehensive metabolic phenotyping was able to reveal severe disturbances in specific AA pathways, in a disease severity dependent way. This information may guide improving nutritional compositions to improve the health of the critically ill patient. CLINICAL TRIAL REGISTRY: Data are from the baseline measurements of study NCT02770092 (URL: https://clinicaltrials.gov/ct2/show/NCT02770092) and NCT03628365 (URL: https://clinicaltrials.gov/ct2/show/NCT03628365).

Case Report: Energy- and Nutrient-Dense Formula for Growth Faltering: A Report of Two Cases From India

Infants hospitalized for critical illnesses are at a high risk of undernutrition because of increased nutrient requirements (due to increased metabolism) and decreased nutrient intake (due to disease-related problems such as anorexia or feeding difficulties). This can result in a slowing down of their normal growth, referred to as “growth faltering.” Appropriate nutritional management of these infants is extremely important to avoid long-term adverse outcomes. Administration of energy- and nutrient-dense formula (ENDF; 100 kcal energy and 2.6 g protein per 100 mL, with added micronutrients) can be an effective means of increasing the nutrient and energy intake of these children. Despite the high prevalence of undernutrition and growth faltering among pediatric patients in India, there is a paucity of literature on the use of ENDF in Indian infants. Herein, we report the successful use of ENDF for the nutritional management of two infants hospitalized for growth faltering because of severe upper airway obstruction. The aim of nutritional management was to achieve satisfactory weight gain, which can lead to spontaneous resolution of upper airway obstruction. ENDF was initially administered to provide 50–100 kcal/kg/day, and the dose was gradually increased to 160–185 kcal/kg/day. Both infants tolerated the formula well and showed satisfactory weight gain. These cases clearly demonstrate that early administration of ENDF is an effective means of increasing nutrient and energy intake of critically ill infants, thereby facilitating catchup growth, without any notable adverse effects.

Assessment of Energy and Protein Requirements in Relation to Nitrogen Kinetics, Nutrition, and Clinical Outcomes in Infants Receiving Early Enteral Nutrition Following Cardiopulmonary Bypass

BACKGROUND

Nutrition therapies in children with congenital heart disease (CHD) after cardiopulmonary bypass (CPB) is crucial, but energy and protein requirements remain undefined. We assessed energy and protein requirements, with nitrogen kinetics and clinical outcomes, in infants with complex CHD following CPB.

METHODS

Infants were randomized to control (1.3 g/kg/d), moderate protein (MP, 2.5 g/kg/d), or high protein (HP, 4 g/kg/d) groups. Resting energy expenditure (REE) was measured 6 hours post-CPB and then at 24-hour intervals, using indirect calorimetry to formulate energy intakes. Enteral formula feeding was initiated 6 hours post-CPB and continued for 5 days. Nitrogen balance (NB); urea nitrogen waste and nitrogen retention; serum prealbumin level; and hepatic, renal, and cardiac function were measured daily. Mid-upper arm circumference and triceps skinfold were measured preoperatively and 5 days after CPB. Adverse outcomes (bacterial infection, reintubation, and cardiac intensive care unit (CICU) stay > 8 days) were recorded.

RESULTS

REE was not different across the 3 groups (P = .37). It declined from 62 ± 6 to 57 ± 7 kcal/kg/d over 5 days post-CPB (P = .02). NB and nitrogen retention became positive by day 3 in the HP group but remained negative in the other 2 groups (P = .045-.003), despite higher urea nitrogen waste in the HP group (P < .0001). The HP group had a greater increase in serum prealbumin level and anthropometric measures (P = .009-.03). Other measures were not significantly different across the 3 groups.

CONCLUSIONS

In infants with complex CHD in the first 5 days post-CPB, protein and energy intakes of ≈4 g/kg/d and 60 kcal/kg/d, respectively, led to improved nutrition outcomes without increased adverse events.

Protein metabolism and requirements in the ICU

The critically ill patient is highly catabolic, loosing significant amounts of protein and muscle. This proteolysis may induce a loss of 20% of the muscle mass in 10 days of hospitalization. Muscle loss may be assessed measuring urinary nitrogen excretion, muscle mass by ultrasound, bioimpedance, computerized tomography or MRI. To reduce the negative nitrogen balance, protein can be administrated enterally, or parenterally through amino acids as a part of parenteral nutrition. ESPEN guidelines recommend to administer 1.3 g/kg/day of protein to critically ill patients but this recommendation should be adapted according to clinical conditions. Elderly, obese, trauma, burn, acute kidney injury patients should receive larger amount of protein.

Nutritional status, intake, and outcomes in critically ill children with bronchiolitis

BACKGROUND

Optimal nutrition in children with severe bronchiolitis remains poorly described. We aimed to describe nutritional status and practices in children with severe bronchiolitis requiring admission to the pediatric intensive care unit (PICU), and explore their associations with outcomes.

METHODS

We conducted a retrospective study on patients with bronchiolitis requiring PICU stay from 2009 to 2014. Demographics, medical data, and baseline weight-for-length Z-scores (WLZ) were collected. In patients requiring more than 48 hours of PICU stay, nutritional intake data in the first 3 days of PICU stay were collected. Underfeeding and overfeeding were defined as the median energy intake of less than 80% and more than 120% of requirements, respectively. Protein adequacy was defined as intake of more than 1.5 g/kg/d. Primary and secondary outcomes of interest were the duration of PICU stay and mechanical ventilation (MV), respectively.

RESULTS

Seventy-four patients were included, with a median PICU stay of 4.9 days (interquartile range 2.0-8.2). Low WLZ at baseline was associated with longer duration of PICU stay (adjusted β: 4.33 [95% confidence interval [CI], 0.49-8.18]; P = .028) and MV days (adjusted β: 4.87 [95% CI, 1.56-8.18]; P = .008) compared to appropriate WLZ. In patients with ≥48 hours PICU stay, protein adequacy was significantly associated with greater PICU (adjusted β coefficient, 6.35 [95% CI, 1.66-11.0]; P = .009) and MV days (adjusted β coefficient, 5.22 [95% CI, 1.06-9.38]; P = .015).

CONCLUSION

Among bronchiolitis patients admitted to the PICU, low WLZ at admission was associated with a longer duration of PICU stay and MV. Protein adequacy was associated with longer PICU and MV days in children with ≥48 hours of PICU stay.

Nutritional support for children during critical illness: European Society of Pediatric and Neonatal Intensive Care (ESPNIC) metabolism, endocrine and nutrition section position statement and clinical recommendations

Background

Nutritional support is considered essential for the outcome of paediatric critical illness. There is a lack of methodologically sound trials to provide evidence-based guidelines leading to diverse practices in PICUs worldwide. Acknowledging these limitations, we aimed to summarize the available literature and provide practical guidance for the paediatric critical care clinicians around important clinical questions many of which are not covered by previous guidelines.

Objective

To provide an ESPNIC position statement and make clinical recommendations for the assessment and nutritional support in critically ill infants and children.

Design

The metabolism, endocrine and nutrition (MEN) section of the European Society of Pediatric and Neonatal Intensive Care (ESPNIC) generated 15 clinical questions regarding different aspects of nutrition in critically ill children. After a systematic literature search, the Scottish Intercollegiate Guidelines Network (SIGN) grading system was applied to assess the quality of the evidence, conducting meta-analyses where possible, to generate statements and clinical recommendations, which were then voted on electronically. Strong consensus (> 95% agreement) and consensus (> 75% agreement) on these statements and recommendations was measured through modified Delphi voting rounds.

Results

The final 15 clinical questions generated a total of 7261 abstracts, of which 142 publications were identified relevant to develop 32 recommendations. A strong consensus was reached in 21 (66%) and consensus was reached in 11 (34%) of the recommendations. Only 11 meta-analyses could be performed on 5 questions.

Conclusions

We present a position statement and clinical practice recommendations. The general level of evidence of the available literature was low. We have summarised this and provided a practical guidance for the paediatric critical care clinicians around important clinical questions.

Electronic supplementary material

The online version of this article (10.1007/s00134-019-05922-5) contains supplementary material, which is available to authorized users.

Review of Outcomes Used in Nutrition Trials in Pediatric Critical Care

BACKGROUND

Generating robust evidence within pediatric intensive care (PIC) can be challenging because of low patient numbers and patient heterogeneity. Systematic reviews may overcome small study biases but are limited by lack of standardization in outcome measures and their definition. Trials of nutrition interventions in PIC are increasing; thus, we wanted to examine the outcome measures being used in these trials.

OBJECTIVE

Our objective was to systematically describe outcome measures used when a nutrition intervention has been evaluated in a PIC randomized controlled trial.

METHODS

A systematic literature review of all studies involving a PIC trial of a nutrition intervention was undertaken from January 1, 1996, until February 20, 2018.

RESULTS

Twenty-nine trials met the criteria and were reviewed. They included a total of 3226 patients across all trials. Thirty-seven primary outcomes and 83 secondary outcomes were found. These were categorized into PIC-related outcomes (infection, intensive care dependency, organ dysfunction, and mortality) and nutrition outcomes (energy targets, nutrition parameters, and feeding tolerance). We found large variation in the outcome measures used. Outcome domains of energy targets, feeding tolerance, and infection were not adequately defined.

CONCLUSIONS

Considerable variation in the outcome measures chosen and their definitions exist within PIC nutrition trials. Optimal nutrition outcomes for PIC must be agreed upon and defined, specifically domains of nutrition efficiency, nutrition tolerance, and non-nutrition PIC outcomes. The next step is to conduct an international Delphi study to gain expert consensus and develop a core outcome set to be reported in future pediatric nutrition trials.

Effects of a nutrient-dense formula compared with a post-discharge formula on post-discharge growth of preterm very low birth weight infants with extrauterine growth retardation: a multicentre randomised study in China

BACKGROUND

Post-discharge optimal growth and nutritional intake have beneficial effects for neurodevelopment in preterm very low birth weight infants (VLBWIs) with extrauterine growth retardation (EUGR). The present study aimed to compare the effects of a nutrient-dense formula (NDF) to a post-discharge formula (PDF) on post-discharge growth of preterm VLBWIs with EUGR.

METHODS

Forty-eight preterm VLBWIs with EUGR at discharge were randomised to receive NDF (100 kcal per 100 mL; 2.6 g protein per 100 mL) or PDF (74 kcal per 100 mL; 1.95 g protein per 100 mL) for 1-6 months until body weight reached the 50th percentile on growth charts with corrected age. Volume, nutrient intake, anthropometry and biochemistry data were collected.

RESULTS

Volume intake was lower in the NDF group than the PDF group during the first 2 months of feeding (P = 0.039 and 0.018, respectively).There were no significant differences in volume intake during months 2-6 of feeding. Energy, protein, carbohydrate and fat intake were higher in the NDF group during months 1-6 of feeding. There were no significant differences in weight, length, and head circumference Z-scores during months 1-6 between the two groups. The △length Z-score from discharge to month 6 was significantly higher in the NDF group than the PDF group (P = 0.043). No differences existed between the two groups with respect to biochemistry.

CONCLUSIONS

After discharge, preterm VLBWIs with EUGR fed a NDF gain anthropometric parameter Z-scores similar to those for a PDF within 6 months of follow-up. A NDF leading to gain in length requires further follow-up.

Comparison of the effect of three different protein content enteral diets on serum levels of proteins, nitrogen balance, and energy expenditure in critically ill infants: study protocol for a randomized controlled trial

Background

Nutritional support is essential in the care of critically ill children since malnutrition in this population is associated with increased morbidity and mortality. Injury in patients admitted to pediatric intensive care units (PICU) results in a catabolic state and augmented protein breakdown, leading to a negative protein balance. Current recommendations about protein prescription in the PICU are fundamentally based on expert opinions, and the minimum threshold is 1.5 g/kg per day of protein, although protein needs could be higher in certain subgroups of patients. The main objectives of the present study are to examine whether the administration of a protein-enriched infant formula increases the serum levels of total proteins, albumin, prealbumin, transferrin, and retinol and improves nitrogen balance and to analyze the effect of the high-protein diet on energy expenditure. A secondary objective is to register possible secondary effects of the protein-enriched diet.

Methods

A multicenter prospective randomized controlled trial (RCT) will be performed in three hospitals. Patients meeting inclusion criteria will be randomly allocated to one of three enteral feeding formulae with different protein contents. Blood and urine test, nitrogen balance assessment, and energy expenditure testing by indirect calorimetry will be performed at the beginning of the nutrition regimen and at 24 h, 72 h and 5–7 days after initiation. The sample size for this trial is estimated to be 90 participants (about 30 participants in each group). The data analysis will be by intention to treat.

Discussion

This RCT will provide new data about the amount of protein needed to improve levels of serum protein and nitrogen balance, a surrogate of protein balance, in critically ill infants receiving enteral nutrition.

Trial registration

ClinicalTrials.gov identifier: NCT03901742. Registered April 1, 2019 – Retrospectively registered.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3686-8) contains supplementary material, which is available to authorized users.

Tolerability and Effects of the Use of Energy-Enriched Infant Formula After Congenital Heart Surgery: A Randomized Controlled Trial

BACKGROUND

Undernutrition is a common problem among children with congenital heart disease (CHD) and may lead to poorer surgical outcomes. A higher intake of energy during the postoperative period of CHD surgery seems to be associated with better outcomes. This study aimed to investigate the effect of the use of energy-enriched formula (EE-formula) compared with normocaloric formula during 30 days after CHD surgery.

METHODS

A randomized controlled trial with patients undergoing heart surgery in a tertiary hospital in southern Brazil from March 2017 to December 2017 was performed. The intervention group received EE-formula (1 kcal/mL), and the control group received normocaloric formula (0.67 kcal/mL). The researcher in charge of anthropometric evaluation was blinded to the randomization.

RESULTS

Fifty-nine patients were included; 30 in control group and 29 in intervention group. There were no statistically significant differences between groups regarding age, gender, anthropometry, and surgical risk classification after randomization. A statistically significant difference in z-score of weight for age and in weight gain variation rate between groups after intervention was observed. Antibiotic use was less frequent in the intervention group, and hospital length of stay was shorter. General gastrointestinal side effects were similar between groups, whereas diarrhea was more frequent in the intervention group. However, this side effect was limited and had spontaneous resolution in 4 out of 6 cases.

CONCLUSION

This study demonstrates that EE-formula use after heart surgery of patients with CHD is well tolerated and may improve short-term nutrition outcome, decrease hospital stay, and reduce antibiotic use.

Peptide nutrient-energy dense enteral feeding in critically ill infants: an observational study

BACKGROUND

Enteral feeding is challenging in critically ill infants. Target intakes are often not achieved as a result of fluid restriction, procedural interruptions and perceived enteral feeding intolerance. In those infants perceived to have poor feeding tolerance, the use of a peptide nutrient-energy dense enteral feed (PEF) may improve nutritional intake and minimise feeding interruptions as a result of gastrointestinal symptoms. The aim of this observational study was to characterise the use of a PEF amongst critically ill infants in two paediatric intensive care units (PICUs).

METHODS

Records from critically ill infants aged <12 months admitted to two PICUs were retrospectively reviewed with a PICU length of stay (LOS) ≥ 7 days. Achievement of nutritional targets for the duration of PEF was reviewed. Gastrointestinal symptoms, including gastric residual volume, constipation and vomiting, were evaluated as tolerance parameters.

RESULTS

In total, 53 infants were included, with a median age on admission of 2.6 months. Median admission weight was 3.9 kg in PICU-1 and 4.7 kg in PICU-2. Median (interquatile range) energy intake in PICU-1 and PICU-2 was 68 (47-92) and 90 (63-124) kcal kg^-1 , respectively, and median (interquatile range) protein intake 1.7 (1.1-2.4) g kg^-1 and 2.5 (1.6-3.2) g kg^-1 , respectively. Feeding was withheld because of feeding intolerance in one infant (4%) on two occasions in PICU-1 for 2.5 h and in two infants (7%) on two occasions in PICU-2 for 19.5 h. Gastric residual mean (SD) volumes were 3.5 (5.4) mL kg^-1 in PICU-1 and 16.9 (15.6) mL kg^-1 in PICU-2.

CONCLUSIONS

Peptide nutrient-energy dense feeding in infants admitted to the PICU is feasible, well tolerated and nutritional targets are met. However, with this study design, it is not possible to draw any conclusions regarding the benefit of PEF over standard PE feed in critically ill children and future work is required to clarify this further.

Nutritional management of young infants presenting with acute bronchiolitis in Belgium, France and Switzerland: survey of current practices and documentary search of national guidelines worldwide

Feeding difficulties are common in young infants presenting with acute bronchiolitis, but limited data is available to guide clinicians adapting nutritional management. We aimed to assess paediatricians' nutritional practices among Western Europe French speaking countries. A survey was disseminated to describe advice given to parents for at home nutritional support, in hospital nutritional management, and preferred methods for enteral nutrition and for intravenous fluid management. A documentary search of international guidelines was concomitantly conducted. Ninety-three (66%) contacted physicians responded. Feeding difficulties were a common indication for infants' admission. Written protocols were rarely available. Enteral nutrition was favoured most of the time when oral nutrition was insufficient and might be withheld in case of severe dyspnoea to decrease respiratory workload. Half of physicians were aware of hyponatremia risk and pathophysiology, and isotonic intravenous solutions were used in less than 15% of centres. International guideline search (23 countries) showed a lack of detailed nutritional management recommendations in most of them.Conclusion: practices were inconsistent among physicians. Guidelines detailed nutritional management poorly. Awareness of hyponatremia risk in relation to intravenous hypotonic fluids and of the safety of enteral hydration and nutrition is insufficient. New guidelines including detailed nutritional management recommendations are urgently needed. What is Known? • Infants presenting with acute bronchiolitis face feeding difficulties. • Underfeeding may promote undernutrition, and intravenous hydration with hypotonic fluids may induce hyponatremia. What is New? • Physicians' nutritional practices are inconsistent and awareness of hyponatremia risk and pathophysiology is insufficient among physicians. • Awareness of hyponatremia risk and pathophysiology is insufficient among physicians. • The reasons for enteral nutrition withholding in bronchiolitis infants are not evidence based, and national guidelines of acute bronchiolitis across the world are elusive regarding nutritional management. • National guidelines of acute bronchiolitis across the world are elusive regarding nutritional management.

Chinese guidelines for the assessment and provision of nutrition support therapy in critically ill children

BACKGROUND

This document represents the first evidence-based guidelines to describe best practices in nutrition therapy in critically ill children (> 1 month and < 18 years), who are expected to require a length of stay more than 2 or 3 days in a Pediatric Intensive Care Unit admitting medical patients domain.

METHODS

A total of 25,673 articles were scanned for relevance. After careful review, 88 studies appeared to answer the pre-identified questions for the guidelines. We used the grading of recommendations, assessment, development and evaluation criteria to adjust the evidence grade based on the quality of design and execution of each study.

RESULTS

The guidelines emphasise the importance of nutritional assessment, particularly the detection of malnourished patients. Indirect calorimetry (IC) is recommended to estimate energy expenditure and there is a creative value in energy expenditure, 50 kcal/kg/day for children aged 1-8 years during acute phase if IC is unfeasible. Enteral nutrition (EN) and early enteral nutrition remain the preferred routes for nutrient delivery. A minimum protein intake of 1.5 g/kg/day is suggested for this patient population. The role of supplemental parenteral nutrition (PN) has been highlighted in patients with low nutritional risk, and a delayed approach appears to be beneficial in this group of patients. Immune-enhancing cannot be currently recommended neither in EN nor PN.

CONCLUSION

Overall, the pediatric critically ill population is heterogeneous, and an individualized nutrition support with the aim of improving clinical outcomes is necessary and important.

Enteral Protein Supplementation in Critically Ill Children: A Randomized Controlled Pilot and Feasibility Study

BACKGROUND

Loss of muscle mass in critically ill children can negatively impact outcomes. The aims of this study were to conduct a pilot randomized control trial (RCT) to examine the difference in protein delivery and nitrogen balance in critically ill children with enteral protein supplementation vs controls. We also aimed to assess the feasibility, safety, and tolerance of the pilot trial.

METHODS

This is a 3-arm RCT in critically ill children eligible for enteral nutrition (EN) therapy. Patients were randomized to 1 of the 3 groups: (1) control (routine EN), (2) polymeric protein module added to EN to reach protein goal by day 4, or (3) oligomeric protein supplementation. Demographics, clinical characteristics, nutrition status, and daily nutrition intake variables were recorded. Protein delivery, nitrogen balance, feasibility variables, and rate of adverse events were the outcomes.

RESULTS

After screening 286 consecutive patients admitted to the pediatric intensive care unit over 11 months, we enrolled and randomized 25 patients. Twenty-two patients (88% of the enrolled) completed the study procedures. Significantly higher protein prescription and actual protein intake within the first 5 days was achieved in the intervention groups, compared with the control group. Nitrogen balance was obtained in 15 patients. There was no significant difference between the groups for the rate of adverse effects and clinical outcomes.

CONCLUSION

In our pilot trial, protein supplementation was safe and well tolerated. Our preliminary results suggest that a larger RCT is potentially feasible, with some modifications of the entry criteria. Trial enrollment was low, likely due to restrictive entry criteria.

Whole Body Protein Turnover and Net Protein Balance After Pediatric Thoracic Surgery: A Noninvasive Single-Dose 15 N Glycine Stable Isotope Protocol With End-Product Enrichment

BACKGROUND

We used the 15 N glycine urinary end-product enrichment technique to quantify whole body protein turnover following thoracic surgery.

MATERIALS AND METHODS

A single dose of 15 N glycine (2 mg/kg) was administered orally on postoperative day 1 to children (1-18 years) following thoracic surgery. 15 N enrichment of ammonia and urea was measured in mixed urine after 12 and 24 hours, respectively, and protein synthesis, breakdown, and net balance determined. Nitrogen balance (dietary intake minus urinary excretion) was calculated. Urinary 3-methylhistidine:creatinine ratio was measured as a marker of skeletal muscle protein breakdown.

RESULTS

We enrolled 19 subjects-median (interquartile range): age, 13.8 years (12.2-15.1); weight, 49.2 kg (38.4-60.8)-who underwent thoracotomy (n = 12) or thoracoscopic (n = 7) surgery. Protein synthesis and breakdown by 15 N enrichment were 7.1 (5.5-9) and 7.1 (5.6-9) g·kg-1 ·d-1 with ammonia (12 hours) as the end product, and 5.8 (3.8-6.7) and 6.7 (4.5-7.6) with urea (24 hours), respectively. Net protein balance by the 15 N glycine and urinary urea nitrogen methods were -0.34 (-0.47, -0.3) and -0.48 (-0.65, -0.28) g·kg-1 ·d-1 , respectively (rs = 0.828, P < .001). Postoperative change in 3-methylhistidine:creatinine ratio did not correlate significantly with protein breakdown or balance.

CONCLUSION

The single-dose oral administration of 15 N glycine stable isotope with measurement of urinary end-product enrichment is a feasible and noninvasive method to investigate whole body protein turnover in children. After major surgery, children manifest increased protein turnover and net negative balance due to increased protein breakdown.

A supplemental intravenous amino acid infusion sustains a positive protein balance for 24 hours in critically ill patients

BACKGROUND

Providing supplemental amino acids to ICU patients during a 3-h period results in improved whole-body net protein balance, without an increase in amino acid oxidation. The primary objective was to investigate if a 24-h intravenous amino acid infusion in critically ill patients has a sustained effect on whole-body protein balance as was seen after 3 h. Secondary objectives were monitoring of amino acid oxidation rate, urea and free amino acid plasma concentrations.

METHODS

An infusion of [1-¹³C]-phenylalanine was added to ongoing enteral nutrition to quantify the enteral uptake of amino acids. Primed intravenous infusions of [ring-²H₅]-phenylalanine and [3,3-²H₂]-tyrosine were used to assess whole-body protein synthesis and breakdown, to calculate net protein balance and to assess amino acid oxidation at baseline and at 3 and 24 hours. An intravenous amino acid infusion was added to nutrition at a rate of 1 g/kg/day and continued for 24 h.

RESULTS

Eight patients were studied. The amino acid infusion resulted in improved net protein balance over time, from -1.6 ± 7.9 μmol phe/kg/h at 0 h to 6.0 ± 8.8 at 3 h and 7.5 ± 5.1 at 24 h (p = 0.0016). The sum of free amino acids in plasma increased from 3.1 ± 0.6 mmol/L at 0 h to 3.2 ± 0.3 at 3 h and 3.6 ± 0.5 at 24 h (p = 0.038). Amino acid oxidation and plasma urea were not altered significantly.

CONCLUSION

We demonstrated that the improvement in whole-body net protein balance from a supplemental intravenous amino acid infusion seen after 3 h was sustained after 24 h in critically ill patients.

TRIAL REGISTRATION

This trial was prospectively registered at Australian New Zealand Clinical Trials Registry. ACTRN, 12615001314516 . Registered on 1 December 2015.

Nutrition and High-Flow Nasal Cannula Respiratory Support in Children With Bronchiolitis

OBJECTIVES

No guidelines are available regarding initiation of enteral nutrition in children with bronchiolitis on high-flow nasal cannula (HFNC) support. We hypothesized that the incidence of feeding-related adverse events (AEs) would not be associated with HFNC support.

METHODS

This retrospective study included children ≤24 months old with bronchiolitis receiving HFNC in a PICU from September 2013 through April 2014. Data included demographics, respiratory support during feeding, and feeding-related AEs. Feeding-related AEs were extracted from nursing documentation and defined as respiratory distress or emesis. Feed route and maximum HFNC delivery were recorded in 8-hour shifts (6 am-2 pm, 2 pm-10 pm, and 10 pm-6 am).

RESULTS

70 children were included, with a median age of 5 (interquartile range [IQR] 2-10) months. HFNC delivery at feed initiation varied widely, and AEs related to feeding occurred rarely. Children were fed in 501 of 794 (63%) of nursing shifts, with AEs documented in only 29 of 501 (5.8%) of those shifts. The incidence of AEs at varying levels of respiratory support did not differ (P = .092). Children in the "early feeding" (fed within first 2 shifts) group (n = 22) had a shorter PICU length of stay (2.2 days [IQR 1.4-3.9] vs 3.2 [IQR 2.5-5.3], P = .006) and shorter duration of HFNC use (26.0 hours [IQR 15.8-57.0] vs 53.5 [IQR 37.0-84.8], P = .002), compared with children in the "late feeding" group (n = 48).

CONCLUSIONS

In this small, single-institution patient cohort, feeding-related AEs were rare and not related to the delivered level of respiratory support.

Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Pediatric Critically Ill Patient: Society of Critical Care Medicine and American Society for Parenteral and Enteral Nutrition

This document represents the first collaboration between two organizations, American Society of Parenteral and Enteral Nutrition and the Society of Critical Care Medicine, to describe best practices in nutrition therapy in critically ill children. The target of these guidelines is intended to be the pediatric (> 1 mo and < 18 yr) critically ill patient expected to require a length of stay greater than 2 or 3 days in a PICU admitting medical, surgical, and cardiac patients. In total, 2,032 citations were scanned for relevance. The PubMed/Medline search resulted in 960 citations for clinical trials and 925 citations for cohort studies. The EMBASE search for clinical trials culled 1,661 citations. In total, the search for clinical trials yielded 1,107 citations, whereas the cohort search yielded 925. After careful review, 16 randomized controlled trials and 37 cohort studies appeared to answer one of the eight preidentified question groups for this guideline. We used the Grading of Recommendations, Assessment, Development and Evaluation criteria to adjust the evidence grade based on assessment of the quality of study design and execution. These guidelines are not intended for neonates or adult patients. The guidelines reiterate the importance of nutritional assessment, particularly the detection of malnourished patients who are most vulnerable and therefore potentially may benefit from timely intervention. There is a need for renewed focus on accurate estimation of energy needs and attention to optimizing protein intake. Indirect calorimetry, where feasible, and cautious use of estimating equations and increased surveillance for unintended caloric underfeeding and overfeeding are recommended. Optimal protein intake and its correlation with clinical outcomes are areas of great interest. The optimal route and timing of nutrient delivery is an area of intense debate and investigations. Enteral nutrition remains the preferred route for nutrient delivery. Several strategies to optimize enteral nutrition during critical illness have emerged. The role of supplemental parenteral nutrition has been highlighted, and a delayed approach appears to be beneficial. Immunonutrition cannot be currently recommended. Overall, the pediatric critical care population is heterogeneous, and a nuanced approach to individualizing nutrition support with the aim of improving clinical outcomes is necessary.

24-Hour protein, arginine and citrulline metabolism in fed critically ill children - A stable isotope tracer study

BACKGROUND & AIMS

The reference method to study protein and arginine metabolism in critically ill children is measuring plasma amino acid appearances with stable isotopes during a short (4-8 h) time period and extrapolate results to 24-h. However, 24-h measurements may be variable due to critical illness related factors and a circadian rhythm could be present. Since only short duration stable isotope studies in critically ill children have been conducted before, the aim of this study was to investigate 24-h appearance of specific amino acids representing protein and arginine metabolism, with stable isotope techniques in continuously fed critically ill children.

METHODS

In eight critically ill children, admitted to the pediatric (n = 4) or cardiovascular (n = 4) intensive care unit, aged 0-10 years, receiving continuous (par)enteral nutrition with protein intake 1.0-3.7 g/kg/day, a 24-h stable isotope tracer protocol was carried out. L-[ring-2H5]-phenylalanine, L-[3,3-2H2]-tyrosine, L-[5,5,5-2H3]-leucine, L-[guanido-15N2]-arginine and L-[5-13C-3,3,4,4-2H4]-citrulline were infused intravenously and L-[15N]-phenylalanine and L-[1-13C]leucine enterally. Arterial blood was sampled every hour.

RESULTS

Coefficients of variation, representing intra-individual variability, of the amino acid appearances of phenylalanine, tyrosine, leucine, arginine and citrulline were high, on average 14-19% for intravenous tracers and 23-26% for enteral tracers. No evident circadian rhythm was present. The pattern and overall 24-h level of whole body protein balance differed per individual.

CONCLUSIONS

In continuously fed stable critically ill children, the amino acid appearances of phenylalanine, tyrosine, leucine, arginine and citrulline show high variability. This should be kept in mind when performing stable isotope studies in this population. There was no apparent circadian rhythm.

CLINICAL TRIAL REGISTER

NCT01511354 on clinicaltrials.gov.

Impact of the structure and dose of protein intake on clinical and metabolic outcomes in critically ill children: A systematic review

OBJECTIVE

The aim of this study was to describe the effects of structure/type and total amount of protein intake on protein balance and clinical outcomes in critically ill children.

METHODS

We conducted a systematic review of relevant literature on Embase, PubMed/Medline, Web of Science, Scopus, and Latin American and Caribbean Health Sciences. A partial gray literature search was undertaken and the reference lists of the selected articles were searched manually. Observational and clinical trials that evaluated the total protein intake, structure of the protein source, or both, in critically ill children were included. Nitrogen balance and clinical outcomes (mortality, length of stay, and duration of mechanical ventilation) were the main outcomes of interest.

RESULTS

We found 18 eligible studies, of which 17 assessed the quantity and one described protein structure in relation to the outcomes. In all, 2118 pediatric critically ill patients <18 y of age were included. The total daily protein intake ranged from 0.67 to 4.7 g/kg. Average daily total protein intake >1.1 g/kg, especially >1.5 g/kg, was associated with positive protein balance and lower mortality.

CONCLUSION

In critically ill children, total daily protein intake >1.1 g/kg was associated with positive effects on clinical outcomes and protein balance. The existing data are not sufficient for determining the optimal structure of protein delivered by enteral route in critically ill children.

Protein Requirements of the Critically Ill Pediatric Patient

This article includes a review of protein needs in children during health and illness, as well as a detailed discussion of protein metabolism, including nitrogen balance during critical illness, and assessment and prescription/delivery of protein to critically ill children. The determination of protein requirements in children has been difficult and challenging. The protein needs in healthy children should be based on the amount needed to ensure adequate growth during infancy and childhood. Compared with adults, children require a continuous supply of nutrients to maintain growth. The protein requirement is expressed in average requirements and dietary reference intake, which represents values that cover the needs of 97.5% of the population. Critically ill children have an increased protein turnover due to an increase in whole-body protein synthesis and breakdown with protein degradation leading to loss of lean body mass (LBM) and development of growth failure, malnutrition, and worse clinical outcomes. The results of protein balance studies in critically ill children indicate higher protein needs, with infants and younger children requiring higher intakes per body weight compared with older children. Monitoring the side effects of increased protein intake should be performed. Recent studies found a survival benefit in critically ill children who received a higher percentage of prescribed energy and protein goal by the enteral route. Future randomized studies should evaluate the effect of protein dosing in different age groups on patient outcomes, including LBM, muscle structure and function, duration of mechanical ventilation, intensive care unit and hospital length of stay, and mortality.

Acquired Amino Acid Deficiencies: A Focus on Arginine and Glutamine

Nonessential amino acids are synthesized de novo and therefore not diet dependent. In contrast, essential amino acids must be obtained through nutrition since they cannot be synthesized internally. Several nonessential amino acids may become essential under conditions of stress and catabolic states when the capacity of endogenous amino acid synthesis is exceeded. Arginine and glutamine are 2 such conditionally essential amino acids and are the focus of this review. Low arginine bioavailability plays a pivotal role in the pathogenesis of a growing number of varied diseases, including sickle cell disease, thalassemia, malaria, acute asthma, cystic fibrosis, pulmonary hypertension, cardiovascular disease, certain cancers, and trauma, among others. Catabolism of arginine by arginase enzymes is the most common cause of an acquired arginine deficiency syndrome, frequently contributing to endothelial dysfunction and/or T-cell dysfunction, depending on the clinical scenario and disease state. Glutamine, an arginine precursor, is one of the most abundant amino acids in the body and, like arginine, becomes deficient in several conditions of stress, including critical illness, trauma, infection, cancer, and gastrointestinal disorders. At-risk populations are discussed together with therapeutic options that target these specific acquired amino acid deficiencies.

Nutritional status, metabolic state and nutrient intake in children with bronchiolitis

Nutrition has a coadjuvant role in the management of children with acute diseases. We aimed to examine nutritional status, macronutrient requirements and actual macronutrient delivery in bronchiolitis. The nutritional status was classified according to WHO criteria and resting energy expenditure (MREE) was measured using an indirect calorimeter. Bland-Altman analysis was used to examine the agreement between MREE and estimated energy expenditure (EEE) with standard equations. Based on the ratio MREE/EEE in relation to Schofield equation on admission, we defined the subjects' metabolic status. A total of 35 patients were enrolled and 46% were malnourished on admission, and 25.8% were hypermetabolic, 37.1% hypometabolic and 37.1% normometabolic. We performed a 24-h recall in 10 children and 80% were overfed (AEI: MREE >120%). Mean bias (limits of agreement) with MREE was 8.9 (-73.9 to 91.8%) for Schofield; 61.0 (-41 to 163%) for Harris-Benedict; and 9.9 (-74.4 to 94.2%) for FAO-WHO equation. Metabolism of infants with bronchiolitis is not accurately estimated by equations.

Does feeding induce maximal stimulation of protein balance?

PURPOSE OF REVIEW

Muscle wasting is dramatic in critically ill patients and related to worsened outcome. The question is whether this can be prevented or reduced by adequate protein feeding. Recommendations for protein requirements are different between different societies, because of limited and weak evidence. Most studies, on which these recommendations are based, use nitrogen balance as primary outcome. However, nitrogen balance to estimate protein needs over short periods, is not reliable.

RECENT FINDINGS

Studies using tracer methodology to assess the effects of feeding on whole-body protein synthesis, breakdown and balance, show that both adult and pediatric critically ill patients can utilize parenterally and enterally given proteins or amino acids to build body protein, and that the extra amino acids are not oxidized.

SUMMARY

Recent studies show a positive correlation between protein intake and protein balance, with many patients reaching a positive protein balance. However, many questions remain. Especially whether adult patients should have a constant positive protein balance, whether the route of administration affects utilization, which proteins are synthesized and whether these are beneficial, is more protein better and what is the upper limit, and whether a positive protein balance affects clinical outcome?

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.

Nutrition in the pediatric population in the intensive care unit

Nutrition is an essential component of patient management in the pediatric intensive care unit (PICU). Poor nutrition status accompanies many childhood chronic illnesses. A thorough assessment of the critically ill child is required to inform the plan for nutrition support. Accurate and clinically relevant nutritional assessment, including growth measurements, provides important guidance. Indirect calorimetry provides the most accurate measurement of resting energy expenditure, but is too often unavailable in the PICU. To prevent inappropriate caloric intake, reassessment of the child's nutrition status is imperative. Enteral nutrition is the recommended route of intake. Human milk is preferred for infants.

Adequate enteral protein intake is inversely associated with 60-d mortality in critically ill children: a multicenter, prospective, cohort study

BACKGROUND

The impact of protein intake on outcomes in pediatric critical illness is unclear.

OBJECTIVE

We examined the association between protein intake and 60-d mortality in mechanically ventilated children.

DESIGN

In a prospective, multicenter, cohort study that included 59 pediatric intensive care units (PICUs) from 15 countries, we enrolled consecutive children (age: 1 mo to 18 y) who were mechanically ventilated for ≥48 h. We recorded the daily and cumulative mean adequacies of energy and protein delivery as a percentage of the prescribed daily goal during the PICU stay ≤10 d. We examined the association of the adequacy of protein delivery with 60-d mortality and determined variables that predicted protein intake adequacy.

RESULTS

We enrolled 1245 subjects (44% female) with a median age of 1.7 y (IQR: 0.4, 7.0 y). A total of 985 subjects received enteral nutrition, 354 (36%) of whom received enteral nutrition via the postpyloric route. Mean ± SD prescribed energy and protein goals were 69 ± 28 kcal/kg per day and 1.9 ± 0.7 g/kg per day, respectively. The mean delivery of enteral energy and protein was 36 ± 35% and 37 ± 38%, respectively, of the prescribed goal. The adequacy of enteral protein intake was significantly associated with 60-d mortality (P < 0.001) after adjustment for disease severity, site, PICU days, and energy intake. In relation to mean enteral protein intake <20%, intake ≥60% of the prescribed goal was associated with an OR of 0.14 (95% CI: 0.04, 0.52; P = 0.003) for 60-d mortality. Early initiation, postpyloric route, shorter interruptions, larger PICU size, and a dedicated dietitian in the PICU were associated with higher enteral protein delivery.

CONCLUSIONS

Delivery of >60% of the prescribed protein intake is associated with lower odds of mortality in mechanically ventilated children. Optimal prescription and modifiable practices at the bedside might enhance enteral protein delivery in the PICU with a potential for improved outcomes. This trial was registered at clinicaltrials.gov as NCT02354521.

Dietary protein in urea cycle defects: How much? Which? How?

Dietary recommendations for patients with urea cycle disorders (UCDs) are designed to prevent metabolic decompensation (primarily hyperammonaemia), and to enable normal growth. They are based on the 'recommended daily intake' guidelines, on theoretical considerations and on local experience. A retrospective dietary review of 28 patients with UCDs in good metabolic control, at different ages, indicates that most patients can tolerate a natural protein intake that is compatible with metabolic stability and good growth. However, protein aversion presents a problem in many patients, leading to poor compliance with the prescribed daily protein intake. These patients are at risk of chronic protein deficiency. Failing to recognise this risk, and further restricting protein intake because of persistent hyperammonaemia may aggravate the deficiency and potentially lead to episodes of metabolic decompensation for which no clear cause is found. These patients may need on-going supplementation with essential amino acids (EAA) to prevent protein malnutrition. Current recommendations for the management of acute metabolic decompensation include cessation of protein intake whilst increasing energy (calorie) intake in the first 24h. We have found that plasma concentrations of all EAA are low at the time of admission to hospital for metabolic decompensation, with correlation between low EAA concentrations, particularly branched-chain amino acids, and hyperammonaemia. Thus, supplementation with EAA should be considered at times of metabolic decompensation. Finally, it would be advantageous to treat patients in metabolic decompensation through enteral supplementation, whenever possible, because of the contribution of the splanchnic (portal-drained viscera) system to protein retention and metabolism.

New ways of defining protein and energy relationships in inborn errors of metabolism

Dietary restrictions required to manage individuals with inborn errors of metabolism (IEM) are essential for metabolic control, however may result in an increased risk to both short and long-term nutritional status. Dietary factors most likely to influence nutritional status include energy intake, protein quality and quantity, micronutrient intake and the frequency and extent to which the diet must be altered during periods of increased physical or metabolic stress. Patients on the most restrictive diets, including those with intakes consisting of low levels of natural protein or those with recurrent illness or frequent metabolic decompensation carry the most nutritional risk. Due to the difficulties in determining condition specific requirements, dietary intake recommendations and nutritional monitoring tools used in patients with IEM are the same as, or extrapolated from, those used in healthy populations. As a consequence, evidence is lacking for the safest dietary prescriptions required to manage these patients long term, as tolerance to dietary therapy is generally described in terms of metabolic stability rather than long term nutritional and health outcomes. As the most frequent therapeutic dietary manipulation in IEM is alteration in dietary protein, and as protein status is critically dependent on adequate energy provision, the use of a Protein to Energy ratio (P:E ratio) as an additional tool will better define the relationship between these critical components. This could accurately define dietary quality and ensure that not only an adequate, but also a safe and balanced intake is provided.

Achieving energy goals at day 4 after admission in critically ill children; predictive for outcome?

BACKGROUND & AIMS

Adequate nutritional intake is essential during pediatric intensive care admission. We investigated whether achievement of energy intake goals at day 4 after admission and route of nutrition were associated with improved outcome.

METHODS

Observational study using prospectively acquired data. Patients receiving enteral and/or parenteral nutrition were included. The energy intake target range at day 4 after admission was 90-110% of resting energy expenditure +10%. Acute malnutrition was defined as weight-for-age <-2 SD. Clinical outcome measures were length of stay, days on ventilator, duration of antibiotics and number of new infections. Data as median (min-max).

RESULTS

Of 325 subjects (age 0.14 (0.0-18.0) year), 19% were acutely malnourished upon admission. Median 86% of energy goals were administered via the enteral route. With enteral energy intake, 7% of patients were fed within the target range, 50% were fed below and 43% were fed above the target range. In a subgroup (n = 223) the acutely malnourished proportion at discharge (26%) was not significantly different from that upon admission (22%). Whether the energy intake was below, within or above the target range did not affect changes in clinical outcome, nor did the route of nutrition.

CONCLUSIONS

Acute malnutrition was highly prevalent upon admission and at discharge. With our nutritional protocol we achieved high rates of (enteral) energy intake. A high percentage of our population received enteral energy above the target energy range. However, there was no association between the amount of energy intake or route of nutrition and clinical outcome.

Nutrition Monitoring in the PICU

The ideal set of variables for nutritional monitoring that may correlate with patient outcomes has not been identified. This is particularly difficult in the PICU patient because many of the standard modes of nutritional monitoring, although well described and available, are fraught with difficulties. Thus, repeated anthropometric and laboratory markers must be jointly analyzed but individually interpreted according to disease and metabolic changes, in order to modify and monitor the nutritional treatment. In addition, isotope techniques are neither clinically feasible nor compatible with the multiple measurements needed to follow progression. On the other hand, indirect alternatives exist but may have pitfalls, of which the clinician must be aware. Risks exist for both overfeeding and underfeeding of PICU patients so that an accurate monitoring of energy expenditure, using targeted indirect calorimetry, is necessary to avoid either extreme. This is very important, since the monitoring of the nutritional status of the critically ill child serves as a guide to early and effective nutritional intervention.

Association of NPO Status and Type of Nutritional Support on Weight and Length of Stay in Infants Hospitalized With Bronchiolitis

OBJECTIVES

We investigated the association of nil per os (NPO) status and subsequent nutritional support with patient weight and length of stay (LOS) during admission for bronchiolitis in patients <2 years old.

METHODS

A retrospective chart review was performed of all patients <2 years old admitted to an academic pediatric hospital between November 2009 and June 2011 with a Current Procedural Terminology code of bronchiolitis. Data extracted from the medical record included respiratory rate, per os/NPO status, use of intravenous fluids, use of enteral tube feedings, weight, and LOS. Patients who did not have 2 weights recorded were excluded. The major outcome measures were weight change during admission and LOS.

RESULTS

The study included 149 patients. The mean ± SD patient age was 3.7 ± 3.8 months, with a median age of 2 months. The median length of stay was 4 days (interquartile range: 3-6). Overall, 16% of patients were made NPO, 75% received intravenous fluids, and 9% received enteral tube feedings. The mean weight loss for all patients was 38 (289) g during the hospitalization, which was not statistically significant. No significant association was found between weight loss and LOS, per os/NPO status, or use of intravenous fluids. However, NPO status was associated with a significant increase in LOS.

CONCLUSIONS

The infants admitted for bronchiolitis did not demonstrate weight loss in this study; however, an association was seen between NPO status and prolonged LOS.

Arginine appearance and nitric oxide synthesis in critically ill infants can be increased with a protein-energy-enriched enteral formula

BACKGROUND

Arginine is considered an essential amino acid during critical illness in children, and supplementation of arginine has been proposed to improve arginine availability to facilitate nitric oxide (NO) synthesis. Protein-energy-enriched enteral formulas (PE-formulas) can improve nutrient intake and promote anabolism in critically ill infants. However, the effect of increased protein and energy intake on arginine metabolism is not known.

OBJECTIVE

We investigated the effect of a PE-formula compared with that of a standard infant formula (S-formula) on arginine kinetics in critically ill infants.

DESIGN

A 2-h stable-isotope tracer protocol was conducted in 2 groups of critically ill infants with respiratory failure because of viral bronchiolitis, who received either a PE-formula (n = 8) or S-formula (n = 10) in a randomized, blinded, controlled setting. Data were reported as means ± SDs.

RESULTS

The intake of a PE-formula in critically ill infants (aged 0.23 ± 0.14 y) resulted in an increased arginine appearance (PE-formula: 248 ± 114 μmol · kg(-1) · h(-1); S-formula: 130 ± 53 μmol · kg(-1) · h(-1); P = 0.012) and NO synthesis (PE-formula: 1.92 ± 0.99 μmol · kg(-1) · h(-1); S-formula: 0.84 ± 0.36 μmol · kg(-1) · h(-1); P = 0.003), whereas citrulline production and plasma arginine concentrations were unaffected.

CONCLUSION

In critically ill infants with respiratory failure because of viral bronchiolitis, the intake of a PE-formula increases arginine availability by increasing arginine appearance, which leads to increased NO synthesis, independent of plasma arginine concentrations. This trial was registered at www.trialregister.nl as NTR515.