Energy metabolism, nitrogen balance, and substrate utilization in critically ill children

Clarifying main nutritional aspects and resting energy expenditure in children with Smith-Magenis syndrome

Our study aims to define resting energy expenditure (REE) and describe the main nutritional patterns in a single-center cohort of children with Smith-Magenis syndrome (SMS). REE was calculated using indirect calorimetry. Patients' metabolic status was assessed by comparing measured REE (mREE) with predictive REE (pREE). Patients also underwent multidisciplinary evaluation, anthropometric measurements and an assessment of average energy intake, using a 3-day food diary, which was reviewed by a specialized dietitian. Twenty-four patients (13 M) were included, the median age was 9 years (IC 95%, 6-14 years), 84% had 17p11.2 deletion, and 16% had RAI1 variants. REE was not reduced in SMS pediatric patients, and the mREE did not differ from the pREE. In patients with RAI1 variants (16%, n = 3/24), obesity was more prevalent than those with 17p11.2 deletion (100% vs 38%). Lower proteins intake and higher total energy intake were reported in obese and overweight patients, compared to healthy weight children. No significant difference was found between males and females in energy or macronutrient intake.

CONCLUSIONS

In SMS, the onset of obesity is not explained by REE abnormalities, but dietary factors seem to be crucial. Greater concern should be addressed to patients with RAI1 variants. A better understanding of the molecular mechanisms causing obesity in SMS patients could set the basis for possible future targeted therapies.

WHAT IS KNOWN

• More than 90% of SMS patients after the age of 10 are overweight or obese.

WHAT IS NEW

• Onset of overweight and obesity in SMS pediatric patients is not explained by abnormal resting energy expenditure. • The development of syndrome-specific dietary guidelines for SMS patients should be of utmost relevance and are highly needed.

Advances in pediatric acute kidney injury pharmacology and nutrition: a report from the 26th Acute Disease Quality Initiative (ADQI) consensus conference

BACKGROUND

In the past decade, there have been substantial advances in our understanding of pediatric AKI. Despite this progress, large gaps remain in our understanding of pharmacology and nutritional therapy in pediatric AKI.

METHODS

During the 26th Acute Disease Quality Initiative (ADQI) Consensus Conference, a multidisciplinary group of experts reviewed the evidence and used a modified Delphi process to achieve consensus on recommendations for gaps and advances in care for pharmacologic and nutritional management of pediatric AKI. The current evidence as well as gaps and opportunities were discussed, and recommendations were summarized.

RESULTS

Two consensus statements were developed. (1) High-value, kidney-eliminated medications should be selected for a detailed characterization of their pharmacokinetics, pharmacodynamics, and pharmaco-"omics" in sick children across the developmental continuum. This will allow for the optimization of real-time modeling with the goal of improving patient care. Nephrotoxin stewardship will be identified as an organizational priority and supported with necessary resources and infrastructure. (2) Patient-centered outcomes (functional status, quality of life, and optimal growth and development) must drive targeted nutritional interventions to optimize short- and long-term nutrition. Measures of acute and chronic changes of anthropometrics, body composition, physical function, and metabolic control should be incorporated into nutritional assessments.

CONCLUSIONS

Neonates and children have unique metabolic and growth parameters compared to adult patients. Strategic investments in multidisciplinary translational research efforts are required to fill the knowledge gaps in nutritional requirements and pharmacological best practices for children with or at risk for AKI.

Nutritional management of children with acute kidney injury-clinical practice recommendations from the Pediatric Renal Nutrition Taskforce

The nutritional management of children with acute kidney injury (AKI) is complex. The dynamic nature of AKI necessitates frequent nutritional assessments and adjustments in management. Dietitians providing medical nutrition therapies to this patient population must consider the interaction of medical treatments and AKI status to effectively support both the nutrition status of patients with AKI as well as limit adverse metabolic derangements associated with inappropriately prescribed nutrition support. The Pediatric Renal Nutrition Taskforce (PRNT), an international team of pediatric renal dietitians and pediatric nephrologists, has developed clinical practice recommendations (CPR) for the nutritional management of children with AKI. We address the need for intensive collaboration between dietitians and physicians so that nutritional management is optimized in line with AKI medical treatments. We focus on key challenges faced by dietitians regarding nutrition assessment. Furthermore, we address how nutrition support should be provided to children with AKI while taking into account the effect of various medical treatment modalities of AKI on nutritional needs. Given the poor quality of evidence available, a Delphi survey was conducted to seek consensus from international experts. Statements with a low grade or those that are opinion-based must be carefully considered and adapted to individual patient needs, based on the clinical judgment of the treating physician and dietitian. Research recommendations are provided. CPRs will be regularly audited and updated by the PRNT.

Nutrition for critically ill children and neonates requiring dialysis: Application of clinical practice recommendations

Approximately 30% of all children and neonates admitted to the intensive care unit (ICU) experience acute kidney injury (AKI). Children with AKI are largely poorly fed and experience high rates of malnutrition. Nutrition prescription and provision are exceptionally challenging for critically ill neonates, infants, and children with AKI given the dynamic nature of AKI and its respective treatment modalities. Managing the nutrition prescription of critically ill neonates, infants, and children with AKI requires nutrition support clinicians to have a high-level understanding of the various treatment modalities for AKI, which can affect the patient's protein, fluid, electrolyte, and mineral needs. Accurate and timely nutrition assessment in critically ill neonates and children with AKI can be flawed owing to difficulty obtaining accurate anthropometric parameters. Recently, the Pediatric Renal Nutrition Taskforce introduced clinical practice recommendations for the nutrition management of children with AKI. In this review, we will discuss the practical implications of these recent guidelines and work to bridge the knowledge and practice gaps for pediatric and neonatal nutrition support clinicians providing nutrition therapy for patients with AKI in the ICU. We also appraise special nutrition-related considerations for neonates with AKI given newer available renal replacement treatment modalities.

Macronutrient and Micronutrient Intake in Children with Lung Disease

This review article aims to summarize the literature findings regarding the role of micronutrients in children with lung disease. The nutritional and respiratory statuses of critically ill children are interrelated, and malnutrition is commonly associated with respiratory failure. The most recent nutrition support guidelines for critically ill children have recommended an adequate macronutrient intake in the first week of admission due to its association with good outcomes. In children with lung disease, it is important not to exceed the proportion of carbohydrates in the diet to avoid increased carbon dioxide production and increased work of breathing, which potentially could delay the weaning of the ventilator. Indirect calorimetry can guide the process of estimating adequate caloric intake and adjusting the proportion of carbohydrates in the diet based on the results of the respiratory quotient. Micronutrients, including vitamins, trace elements, and others, have been shown to play a role in the structure and function of the immune system, antioxidant properties, and the production of antimicrobial proteins supporting the defense mechanisms against infections. Sufficient levels of micronutrients and adequate supplementation have been associated with better outcomes in children with lung diseases, including pneumonia, cystic fibrosis, asthma, bronchiolitis, and acute respiratory failure.

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.

External Validation of Equations to Estimate Resting Energy Expenditure in Critically Ill Children and Adolescents with and without Malnutrition: A Cross-Sectional Study

We evaluated the validity of sixteen predictive energy expenditure equations for resting energy expenditure estimation (eREE) against measured resting energy expenditure using indirect calorimetry (REEIC) in 153 critically ill children. Predictive equations were included based on weight, height, sex, and age. The agreement between eREE and REEIC was analyzed using the Bland−Altman method. Precision was defined by the 95% limits of the agreement; differences > ±10% from REEIC were considered clinically unacceptable. The reliability was assessed by the intraclass correlation coefficient (Cronbach’s alpha). The influence of anthropometric, nutritional, and clinical variables on REEIC was also assessed. Thirty (19.6%) of the 153 enrolled patients were malnourished (19.6%), and fifty-four were overweight (10.5%) or obese (24.8%). All patients received sedation and analgesia. Mortality was 3.9%. The calculated eREE either underestimated (median 606, IQR 512; 784 kcal/day) or overestimated (1126.6, 929; 1340 kcal/day) REEIC compared with indirect calorimetry (928.3, 651; 1239 kcal/day). These differences resulted in significant biases of −342 to 592 kcal (95% limits of agreement (precision)−1107 to 1380 kcal/day) and high coefficients of variation (up to 1242%). Although predicted equations exhibited moderate reliability, the clinically acceptable ±10% accuracy rate ranged from only 6.5% to a maximum of 24.2%, with the inaccuracy varying from −31% to +71.5% of the measured patient’s energy needs. REEIC (p = 0.017) and eREE (p < 0.001) were higher in the underweight compared to overweight and obese patients. Apart from a younger age, malnutrition, clinical characteristics, temperature, vasoactive drugs, neuromuscular blockade, and energy intake did not affect REEIC and thereby predictive equations’ accuracy. Commonly used predictive equations for calculating energy needs are inaccurate for individual patients, either underestimating or overestimating REEIC compared with indirect calorimetry. Altogether these findings underscore the urgency for measuring REEIC in clinical situations where accurate knowledge of energy needs is vital.

Proceedings of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition Monothematic Conference, 2020: "Acute Liver Failure in Children": Treatment and Directions for Future Research

OBJECTIVES

The Hepatology Committee of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) aims to educate pediatric gastroenterologists, members of ESPGHAN and professionals from other specialties promoting an exchange of clinical expertise in the field of pediatric hepatology.

METHODS

The 2020 single topic ESPGHAN monothematic 3-day conference on pediatric liver disease, was organized in Athens, Greece and was entitled " Acute Liver Failure" (ALF). ALF is a devastating disease with high mortality and in a considerable fraction of patients, the cause remains unresolved. As knowledge in diagnosis and treatment of ALF in infants and children has increased in the past decades, the objective was to update physicians in the field with developments in medical therapy and indications for liver transplantation (LT) and to identify areas for future research in clinical and neurocognitive outcomes in ALF.

RESULTS

We recently reported the epidemiology, diagnosis, and initial intensive care management issues in separate manuscript. Herewith we report on the medical treatment, clinical lessons arising from pediatric studies, nutritional and renal replacement therapy (RRT), indications and contraindications for LT, neurocognitive outcomes, new techniques used as bridging to LT, and areas for future research. Oral presentations by experts in various fields are summarized highlighting key learning points.

CONCLUSIONS

The current report summarizes the current insights in medical treatment of pediatric ALF and the directions for future research.

A methodological and clinical approach to measured energy expenditure in the critically ill pediatric patient

The metabolic response to injury and stress is characterized initially by a decreased energy expenditure (Ebb phase) followed by an increased metabolic expenditure (Flow phase). Indirect calorimetry is a methodology utilized to measure energy expenditure and substrate utilization by measuring gas exchange in exhaled air and urinary nitrogen. The use of indirect calorimetry in critically ill patients requires precise equipment to obtain accurate measurements. The most recent guidelines suggested that measured energy expenditure by indirect calorimetry be used to determine energy requirements. This article reviews the methodological and clinical use of indirect calorimetry in critically ill pediatric patients.

Children of the abyss: Investigating the association between isotopic physiological stress and skeletal pathology in London during the Industrial Revolution

OBJECTIVE

This project sought to investigate whether an association may be observed between isotopic stress indicators and skeletal evidence of pathological conditions.

MATERIALS

Deciduous and permanent teeth of 15 non-adults from two contemporaneous mid-19th century London burial grounds (City Bunhill, Lukin Street).

METHODS

δ¹³C and δ¹⁵N was measured in the incrementally sectioned dentine collagen. Isotopic profiles for each individual included death during tooth development.

RESULTS

Individuals with skeletal evidence of chronic pathological conditions (e.g., rickets, tuberculosis) exhibited raised δ¹⁵N values of 0.5-1.7‰ in the months prior to death. Isotopic change consistent with chronic physiological stress prior to death was also recorded in two individuals with no skeletal evidence of disease. An offset was observed between co-forming bone and dentine δ¹⁵N values in both populations, indicating that bone and dentine are not recording the same isotopic changes.

CONCLUSIONS

Isotopic change consistent with chronic physiological stress was observed in both those with and without skeletal evidence of disease, suggesting that adaptation to chronic stress in childhood was not uncommon within these 19th century London populations.

SIGNIFICANCE

Chronic physiological stress prior to death may be seen in the incrementally sampled dentine of non-adults who die during tooth formation.

LIMITATIONS

The temporal resolution of current dentine micro-sampling methods may mask or minimise visibility of shorter-term periods of stress or dietary change.

SUGGESTIONS FOR FURTHER RESEARCH

Future research should further explore the relationship between specific skeletal pathologies and isotopic evidence for stress.

Pediatric Multi-Organ Dysfunction Syndrome: Analysis by an Untargeted "Shotgun" Lipidomic Approach Reveals Low-Abundance Plasma Phospholipids and Dynamic Recovery over 8-Day Period, a Single-Center Observational Study

Lipids are molecules involved in metabolism and inflammation. This study investigates the plasma lipidome for markers of severity and nutritional status in critically ill children. Children with multi-organ dysfunction syndrome (MODS) (n = 24) are analyzed at three time-points and cross-referenced to sedation controls (n = 4) for a total of N = 28. Eight of the patients with MODS, needed veno-arterial extracorporeal membrane oxygenation (VA ECMO) support to survive. Blood plasma lipid profiles are quantified by nano-electrospray (nESI), direct infusion high resolution/accurate mass spectrometry (MS), and tandem mass spectrometry (MS/MS), and compared to nutritional profiles and pediatric logistic organ dysfunction (PELOD) scores. Our results show that PELOD scores were not significantly different between MODS and ECMO cases across time-points (p = 0.66). Lipid profiling provides stratification between sedation controls and all MODS patients for total lysophosphatidylserine (lysoPS) (p-value = 0.004), total phosphatidylserine (PS) (p-value = 0.015), and total ether-linked phosphatidylethanolamine (ether-PE) (p-value = 0.03) after adjusting for sex and age. Nutrition intake over time did not correlate with changes in lipid profiles, as measured by caloric and protein intake. Lipid measurement in the intensive care environment shows dynamic changes over an 8-day pediatric intensive care unit (PICU) course, suggesting novel metabolic indicators for defining critically ill children.

Relationship between inflammation and metabolic regulation of energy expenditure by GLP-1 in critically ill children

BACKGROUND & AIMS

Critical illness is associated with derangement in the metabolic and inflammatory response. Previous investigators have highlighted the cross-link between feeding, inflammation and gut homeostasis. Glucagon like peptide-1 (GLP-1) is a gut derived hormone that plays an important role in the modulation of energy metabolism through appetite regulation and promotion of gastric motility. Growing evidence suggests that GLP-1 might influence energy expenditure. The aim of this study was to assess the relationship between inflammatory activation and metabolic regulation of energy expenditure by assessing cytokine release, levels of GLP-1 and energy expenditure in a cohort of critically ill children.

METHOD

This is a prospective study conducted in critically ill children. A blood sample was collected from each child during the first few days of critical illness, for the analysis of serum inflammatory cytokines (TNF-α, IL-10, IL-6 and IL-1β) and GLP-1 in 42 children. Indirect calorimetry (IC) measurements were performed concurrently in a subset of 21 children. The metabolic index was determined using the ratio of Measured Resting Energy Expenditure (MREE)/Predicted Resting Energy Expenditure (PREE) based on the Schofield equation. Correlation analysis was performed, followed by a stepwise linear regression analysis to assess factors affecting GLP-1 and the metabolic index.

RESULTS

A total of 42 children (0-14 years) were included in this study. The regression analysis indicated that CRP, TNF-α, IL-6 and IL-1β statistically influenced GLP-1 concentrations (p < 0.01). Where IC measurements were performed (N = 21), GLP-1 showed a statistically significant association with the metabolic index (p < 0.01). No evidence of statistical association was recorded between the inflammatory mediators and the metabolic index. Overall the results showed that circulating GLP-1 was increased in response to inflammatory stimuli in critically ill children. GLP-1 contributed to the changes observed in MREE induced by critical illness in our cohort.

CONCLUSION

Energy expenditure is extremely variable in critically ill children, our study suggests that changes in GLP-1 might contribute to a significant amount of this variation. If confirmed in larger studies, GLP-1 could be used as a correction factor for REE predictive equations in critically ill children.

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.

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.

Energy Balance in Critically Ill Children With Severe Sepsis Using Indirect Calorimetry: A Prospective Cohort Study

OBJECTIVES

Energy needs in critically ill children are dynamic and variable. Data on energy balance in children with severe sepsis using indirect calorimetry (IC) is lacking. Thus, we planned to study the energy needs and balance of this cohort.

METHODS

Prospective observational study conducted in ventilated children aged 5 to 12 years, admitted in pediatric intensive care unit with severe sepsis from May 2016 to June 2017. Measured resting energy expenditure (mREE) was measured with IC (Quark RMR, COSMED) till 7 days or pediatric intensive care unit discharge. Predicted energy expenditure (pREE) was estimated using Schofield, Harris and Benedict, and FAO/WHO/UNU equations. Primary outcome was to study the daily energy balance. Secondary outcome was to determine nitrogen balance and agreement of mREE with pREE.

RESULTS

Forty children (24 boys) with median age of 7 (5.2, 10) years were enrolled. All received enteral nutrition; 35 (87.5%) received inotropic support. Median ventilation-free days were 19 days and 4 children died (10%). A total of 176 IC measurements were obtained with an average of 4 per patient. The mean mREE was 51 ± 17 kcal/kg and mean respiratory quotient was 0.77 ± 0.07. There was persistent negative energy balance from days 1 to 7 and negative nitrogen balance from days 1 to 5. There was poor agreement of pREE with mREE using Bland Altman plots. None of severity of illness scores (PRISM III, daily Sequential Organ Function Assessment, daily Vasoactive Inotropic Score) showed correlation with mREE.

CONCLUSIONS

Persistent negative energy and nitrogen balance exist during acute phase of severe sepsis. Predictive equations are inaccurate compared with IC as the criterion standard.

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.

Resting energy expenditure in infants with congenital diaphragmatic hernia without respiratory support at time of neonatal hospital discharge

BACKGROUND

Infants with congenital diaphragmatic hernia (CDH) are at risk for growth failure because of inadequate caloric intake and high catabolic stress. There is limited data on resting energy expenditure (REE) in infants with CDH.

AIMS

To assess REE via indirect calorimetry (IC) in term infants with CDH who are no longer on respiratory support and nearing hospital discharge with advancing post-conceptional age and to assess measured-to-predicted REE using predictive equations.

METHODS

A prospective cohort study of term infants with CDH who were no longer on respiratory support and nearing hospital discharge was conducted to assess REE via IC and caloric intake. Baseline characteristics and hospital course data were collected. Three day average caloric intake around time of IC testing was calculated. Change in REE with advancing post-conceptional age and advancing post-natal age was assessed. The average measured-to-predicted REE was calculated for the cohort using predictive equations [22].

RESULTS

Eighteen infants with CDH underwent IC. REE in infants with CDH increased with advancing postconceptional age (r2 = 0.3, p < 0.02). The mean REE for the entire group was 53.2 +/- 10.9 kcal/kg/day while the mean caloric intake was 101.2 +/- 17.4 kcal/kg/day. The mean measured-to-predicted ratio for the cohort was in the normal metabolic range (1.10 +/- 0.17) with 50% of infants considered hypermetabolic and 11% of infants considered hypo-metabolic.

CONCLUSIONS

Infant survivors of CDH repair who are without respiratory support at time of neonatal hospital discharge have REE, as measured by indirect calorimetry, that increases with advancing post-conceptional age and that is within the normal metabolic range when compared to predictive equations.

LEVEL OF EVIDENCE

III.

Association between enteral macronutrient delivery and inflammatory response in critically ill children

BACKGROUND AND AIMS

An important goal of nutrition support in paediatric critical illness is minimising catabolism. While focussing on providing full energy requirements, macronutrient balance is often neglected. Studies suggest that there is interplay between nutrition and inflammation. We aimed to assess the amount of enteral macronutrients delivered compared to estimated requirements, and the association between delivered macronutrients and systemic inflammation in critically ill children.

METHOD

We prospectively evaluated energy and macronutrient intake in critically ill children who required at least 72 h of mechanical ventilation. Data on enteral energy and macronutrient intake was collected and expressed as a percentage of the estimated requirements. Circulating levels of inflammatory cytokines were measured by ELISA and association assessed with delivery of macronutrients from the previous 24 h.

RESULTS

A total of 87 children (0-16 years) were included in this study. By day 3 the median (IQR) intake of energy, fat, carbohydrate (CHO) and protein were 75% (50-103), 85% (43-120), 63% (42-102) and 45% (23-65) respectively. We have also shown that delivery of enteral fat and protein was associated with elevation in the levels of tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6).

CONCLUSION

The inflammatory response in critically ill children is influenced by the amount of enteral fat and protein delivered. Our data suggests that within the feed delivered, fat is often higher than protein and CHO. It is crucial to take into account the proportion of macronutrients required and not only aim to achieve the energy goal.

Malnutrition Risk in Hospitalized Children: A Descriptive Study of Malnutrition-Related Characteristics and Development of a Pilot Pediatric Risk-Assessment Tool

BACKGROUND

Underrecognition of pediatric malnutrition may affect nutrition interventions and outcomes. Pediatric malnutrition uses more specific etiology-based criteria but lacks clarity in implementation guidelines. Study goals were to identify malnutrition and risk among hospitalized patients, characterize malnutrition risk factors, and assess reliability of criteria against outcome measures.

MATERIALS AND METHODS

All children 44 weeks postmenstrual age-18 years, admitted for 48 hours during a 16-day period, were included (n = 528). Trained dietitians assessed patients in physical assessments (PA), growth, energy intake, increased nutrient losses (IL), altered absorption of nutrients (AA), hypermetabolism and inflammation, laboratory information, micronutrient deficiency, and functional status. Outcome data assessed were length of stay (LOS), intensive care unit (ICU) LOS, ventilation days, nutrition support, and dietitian intervention.

RESULTS

Malnutrition prevalence upon admission was 19.7%. Weight/length or BMI/age z-score (ZS) had no effect on LOS. AA and IL upon admission were independently associated with malnutrition (both, P<.01). Wasting and hypermetabolism were independently associated with longer LOS (P<.01). Other factors associated with longer LOS included IL and inflammation (P < .05). Those with hypermetabolism had significant ZS improvements if followed by a dietitian (P < .05). Wasting via PA was the only factor associated with longer ICU LOS (P < .05).

CONCLUSIONS

Identification of risk factors (wasting, hypermetabolism, AA, IL) beyond anthropometrics to define malnutrition and risk is important in prioritizing care in a tertiary pediatric facility. Of great significance is the ability of dietitian-based PA to predict LOS and need for intervention.

Preventing Underfeeding and Overfeeding: A Clinician's Guide to the Acquisition and Implementation of Indirect Calorimetry

BACKGROUND

In critically ill patients, indirect calorimetry (IC) is the gold standard to determine energy needs, as the use of predictive equations can result in underfeeding or overfeeding. The aim of this quality improvement (QI) initiative was to describe the rationale for and implementation of a process to target energy provision according to IC measurements in a tertiary academic medical center pediatric intensive care unit (PICU).

MATERIALS AND METHODS

To justify the purchase of an indirect calorimeter for clinical use, a needs assessment was conducted, followed by a training and implementation period. PICU patients were selected for IC according to published guidelines. Measured energy expenditure was compared with predicted energy expenditure and the provided energy prescription. The dietitians assessed IC results and adjusted energy prescriptions, if indicated.

RESULTS

Thirty-five total tests were completed with 24 patients. Sixty-nine percent of measurements resulted in energy delivery adjustments. Fifteen (47%) energy prescriptions decreased by a mean of 27% ± 11%, and 7 (22%) increased by a mean of 17% ± 15%. Staff and patient/guardians accommodated the use of IC, and PICU dietitian recommendations for IC tests and to adjust nutrition regimens were universally implemented.

CONCLUSIONS

Data to support the procurement of IC are vital to promote best practice to measure energy expenditure. Critically ill pediatric patients exhibit metabolic alterations that cannot be predicted by standard equations. Our QI initiative demonstrated the implementation and application of IC in the critically ill population and the ability to target energy provision to prevent energy imbalances.

Association of BMI With Propofol Dosing and Adverse Events in Children With Cancer Undergoing Procedural Sedation

OBJECTIVES

Obesity increases the risk of complications during pediatric procedural sedation. The risk of being underweight has not been evaluated in this arena. We therefore investigated the association of BMI with sedation dosing and adverse events in children across a range of BMIs.

METHODS

A total of 1976 patients ages 2 to 21 years old with oncologic diagnoses underwent lumbar punctures and/or bone marrow aspirations. All children received a standard adjunctive dose of ketamine before sedation with propofol. Weight categories were stratified by BMI percentile: underweight <5%, normal weight 5% to 85%, overweight >85%, and obese >95%. Dosing and adverse events (hypoxia, apnea, bradycardia, or hypotension) were reviewed.

RESULTS

There were no differences in propofol dosing for procedural sedation between patients who were normal weight and underweight. However, children who were overweight and those who were obese used less propofol compared with children who were normal weight (P < .01). Children who were underweight had a higher proportion of adverse events overall relative to those children of normal weight (P < .001). In contrast, there was not an increase in adverse events for patients who were overweight and obese.

CONCLUSIONS

Children who are overweight and children with obesity who require deep sedation can undergo successful sedation with lower propofol dosing relative to children of a normal weight. This dosing strategy may help to mitigate the risks associated with sedating patients who are obese. Notably, children who were underweight had an increased rate of complications despite receiving an equal amount of sedation compared with patients who were normal weight. This should alert the clinicians to the risks associated with sedating children who are underweight.

Nutritional management in the critically ill child with acute kidney injury: a review

Acute kidney injury (AKI) in critically ill children is frequently a component of the multiple organ failure syndrome. It occurs within the framework of the severe catabolic phase determined by critical illness and is intensified by metabolic derangements. Nutritional support is a must for these children to improve outcomes. Meeting the special nutritional needs of these children often requires nutritional supplementation by either the enteral or the parenteral route. Since critically ill children with AKI comprise a heterogeneous group of subjects with varying nutrient needs, nutritional requirements should be frequently reassessed, individualized and carefully integrated with renal replacement therapy. This article is a state-of-the-art review of nutrition in critically ill children with AKI.

Early enteral nutrition therapy in congenital cardiac repair postoperatively: A randomized, controlled pilot study

Background and Objectives:

Adequate nutritional supplementation in infants with cardiac malformations after surgical repair is a challenge. Critically ill infants in the early postoperative period are in a catabolic stress. The mismatch between estimated energy requirement (EER) and the intake in the postoperative period is multifactorial, predisposing them to complications such as immune deficiency, more infection, and growth failure. This study aimed to assess the feasibility and efficacy of enriched breast milk feed on postoperative recovery and growth of infants after open heart surgery.

Methodology:

Fifty infants <6 months of age were prospectively randomized in the trial for enteral nutrition (EN) postoperatively from day 1 to 10, after obtaining the Institute Ethics Committee's approval. They were equally divided into two groups on the basis of the feed they received: Control group was fed with expressed breast milk (EBM; 0.65 kcal/ml) and intervention group was fed with EBM + energy supplementation/fortification with human milk fortifier (7.5 kcal/2 g)/Simyl medium-chain triglyceride oil (7.8 kcal/ml). Energy need for each infant was calculated as per EER at 90 kcal/kg/day, as the target requirement. The intra- and post-operative variables such as cardiopulmonary bypass and aortic cross-clamp times, ventilation duration, Intensive Care Unit (ICU), and hospital length of stay and mortality were recorded. Anthropometric and hematological parameters and infection control data were recorded in a predesigned pro forma. Data were analyzed using Stata 14.1 software.

Results:

The duration of mechanical ventilation, length of ICU stay (LOIS), length of hospital stay (LOHS), infection rate, and mortality rate were lower in the intervention group compared to the control group although none of the differences were statistically significant. Infants in control group needed mechanical ventilation for about a day more (i.e., 153.6 ± 149.0 h vs. 123.2 ± 107.0 h; P = 0.20) than those in the intervention group. Similarly, infants in control group stayed for longer duration in the ICU (13.2 ± 8.9 days) and hospital (16.5 ± 9.8 days) as compared to the intervention group (11.0 ± 6.1 days; 14.1 ± 7.0 days) (P = 0.14 and 0.17, respectively). The LOIS and LOHS were decreased by 2.2 and 2.4 days, respectively, in the intervention group compared to control group. The infection rate (3/25; 5/25) and mortality rate (1/25; 2/25) were lower in the intervention group than those in the control group. The energy intake in the intervention group was 40 kcal more (i.e., 127.2 ± 56.1 kcal vs. 87.1 ± 38.3 kcal) than the control group on the 10^th postoperative day.

Conclusions:

Early enteral/oral feeding after cardiac surgery is feasible and recommended. In addition, enriching the EBM is helpful in achieving the maximum possible calorie intake in the postoperative period. EN therapy might help in providing adequate nutrition, and it decreases ventilation duration, infection rate, LOIS, LOHS, and mortality.

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.

Growth in very preterm children: Head growth after discharge is the best independent predictor for cognitive outcome

BACKGROUND

The contribution of growth parameters to the cognitive outcome of very low birth weight (VLBW)/very preterm (VP) infants is difficult to disentangle from other preterm-birth related factors.

AIMS

We hypothesized that long-term cognitive and motor outcome of VLBW/VP infants is most strongly associated with growth in head circumference after hospital discharge.

STUDY DESIGN

Single-centre prospective longitudinal study: anthropometric measures at different time points (birth, discharge, school-age).

SUBJECTS

136 VLBW/VP infants (<32weeks gestation/birth weight<1.500g).

OUTCOME MEASURES

Cognitive and motor function (Kaufman Assessment Battery for Children; Movement Assessment Battery for Children) at school-age (6.7-10.0years, mean=8.2).

RESULTS

In hierarchical multiple regression analyses, growth from birth to discharge significantly predicted cognitive outcome (weight: R²_change=0.063, p=0.014; length: R²_change=0.078, p=0.007; HC: R²_change=0.050, p=0.030), as well as weight gain (R²_change=0.096, p=0.001) and head growth (R²_change=0.134, p<0.001) from discharge to school-age. While most growth parameters, especially those from birth to discharge, were significantly influenced by prenatal growth and immaturity related morbidity (R²=0.151 to 0.605, all p≤0.001), head growth after discharge was not (R²=0.029, p=0.461).

CONCLUSIONS

Amongst all anthropometric measures, head growth between discharge and school-age is the best independent predictor for cognitive outcome in VLBW/VP infants. Determinants of head growth after discharge need further studies to identify targets for intervention.

Protein Feeding in Pediatric Acute Kidney Injury Is Not Associated With a Delay in Renal Recovery

OBJECTIVE

Critically ill children with acute kidney injury (AKI) are at high risk of underfeeding. Newer guidelines for nutrition support recommend higher protein intake. Therefore, the study evaluated the effects of protein feeding on the resolution of AKI and compared energy and protein intake in patients with and without AKI after implementation of Nutrition Support guidelines.

DESIGN

Retrospective study.

SUBJECTS

Five hundred twenty critically ill children from October 2012 to June 2013 and October to December 2013.

MAIN OUTCOME MEASURE

Energy and protein intake in patients with no AKI, resolved, or persistent AKI. Energy and protein intake was documented for days 1-8 of Pediatric Intensive Care Unit stay and in the postimplementation versus preimplementation period of nutrition support guidelines. AKI was defined by modified pRIFLE. Persistent AKI was defined as patients who did not resolve their AKI during the study period.

RESULTS

A higher percentage of patients with resolved and persistent AKI met ≥ 80% of protein needs versus no AKI. After adjustment for Pediatric Risk of Mortality Score, the odds ratio for protein intake of ≥ 80% compared to <80% of estimated protein needs was not significant, which suggests that higher protein intake was not associated with nonresolution of AKI. There were significant improvements in the cumulative protein gap in patients with no AKI in the postimplementation (-1.0 [-1.7 to -0.6] g/kg/day) compared to preimplementation period (-1.3 [-1.7 to -0.9] g/kg/day, P = .001) and persistent AKI in the postimplementation (-0.8 [-1.4 to -0.1] g/kg/day) compared to preimplementation (-1.3 [-1.7 to -0.9] g/kg/day, P = .03).

CONCLUSIONS

Higher protein intake was not associated with a delay in renal recovery in patients with AKI after adjustment for severity of illness. Protein intake was improved in critically ill children with no AKI, resolved, and persistent AKI after implementation of Nutrition Support Guidelines, but underfeeding persisted in these patients.

Glucose Metabolism and Associated Outcome After Pediatric Liver Transplantation

BACKGROUND

Despite hypoglycemia and hyperglycemia being frequently observed in the early postoperative phase, information on glucose metabolism after pediatric liver transplantation (pLT) is scarce.

METHODS

The goal of this retrospective single-center study, which included 46 patients who consecutively underwent 55 liver transplantations, was to gather data on glucose uptake, the prognostic relevance of hyperglycemia, and the safety of insulin administration in patients after pLT.

RESULTS

In this study population, glucose intake to keep blood sugar levels (BSLs) within the targeted range of 120 to 200 mg/dL (6.7-11.1 mmol/L) increased rapidly over the first few postoperative days and was significantly correlated with graft function. There was no association between a postoperative daily mean BSL >200 mg/dL and specific posttransplant complications (acute rejection, infection, need for retransplantation, and/or death). High postoperative mean 7-day BSLs were associated with poor glucose metabolism and an increase in morbidity and 6-month posttransplant mortality. Hypoglycemia was not observed under insulin administration.

CONCLUSIONS

With high BSLs being associated with poor glucose metabolism, it is likely that the critical illness itself, in addition to poor graft function, causes the increase in morbidity and mortality, with hyperglycemia serving as a marker.

The successful accomplishment of nutritional and clinical outcomes via the implementation of a multidisciplinary nutrition support team in the neonatal intensive care unit

Background

Nutritional support is critical for preterm infants in the neonatal intensive care unit (NICU). A multidisciplinary nutritional support team (NST) that focuses on providing optimal and individualized nutrition care could be helpful. We conducted a thorough evaluation of clinical and nutritional outcomes in a tertiary NICU following the implementation of an NST.

Methods

This study used a retrospective approach with historical comparisons. Preterm neonates < 30 weeks gestational age or weighing < 1250 g were enrolled. Clinical and nutritional outcomes were compared before and after the establishment of the NST. Medical records were reviewed, and clinical and nutritional outcomes were compared between the two groups.

Results

In total, 107 patients from the pre-NST period and 122 patients from the post-NST period were included. The cumulative energy delivery during the first week of life improved during the post-NST period (350.17 vs. 408.62 kcal/kg, p < 0.001). The cumulative protein and lipid deliveries also significantly increased. The time required to reach full enteric feedings decreased during the post-NST period (6.4 ± 5.8 vs. 4.7 ± 5.1 days, p = 0.016). Changes of Z-score in weight from admission to discharge exhibited more favorable results in the post-NST period (−1.13 ± 0.99 vs.−0.91 ± 0.74, p = 0.055), and the length of ICU stay significantly decreased in the post-NST period (81.7 ± 36.6 vs. 72.2 ± 32.9 days, p = 0.040).

Conclusions

NST intervention in the NICU resulted in significant improvements in the provision of nutrition to preterm infants in the first week of life. There were also favorable clinical outcomes, such as increased weight gain and reduced length of ICU stay. Evaluable data remain sparse in the NICU setting with premature neonatal populations; therefore, the successful outcomes identified in this study may provide support for NST practices.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-016-0648-0) contains supplementary material, which is available to authorized users.

Improving growth in preterm infants during initial hospital stay: principles into practice

Despite recent innovations in nutritional care, postnatal growth failure between birth and hospital discharge remains a significant problem in preterm infants. Whether or not it is entirely preventable is unclear. What is clear is that feeding practices and growth outcomes vary widely between neonatal intensive care units (NICUs). This partly reflects lack of data in key areas but it also reflects inconsistent translation of principles into practice and limitations in the way infants are fed and growth monitored in the NICU. These issues will be reviewed, in the process underline the key roles that audit, standardised feeding protocol, individualised nutritional care and a nutritional support team play in improving outcome in these high-risk infants.

Nutrition Support for Children Undergoing Congenital Heart Surgeries: A Narrative Review

Energy imbalance in infants and children with congenital heart disease (CHD) is common and influenced by age, underlying cardiac diagnoses, and presence or absence of congestive heart failure. During the surgical hospitalization period, these children are prone to nutritional deterioration due to stress of surgery, anesthetic/perfusion techniques, and postoperative care. Poor nutrition is associated with increased perioperative morbidity and mortality. This review aims to examine various aspects of nutrition in critically ill children with CHD, including (1) energy expenditure, (2) perioperative factors that contribute to energy metabolism, (3) bedside practices that are potentially able to optimize nutrient delivery, and (4) medium- to long-term impact of energy balance on clinical outcomes. We propose a nutrition algorithm to optimize nutrition of these children in the perioperative period where improvements in nutrition status will likely impact surgical outcomes.

Resting energy expenditure, macronutrient utilization, and body composition in term infants after corrective surgery of major congenital anomalies: A case-study

INTRODUCTION

Knowledge on the metabolic changes and nutritional needs during the postsurgical anabolic phase in infants is scarce. This analysis explores the associations of resting energy expenditure (REE) and macronutrient utilization with body composition of full-term infants, during catch-up growth after corrective surgery of major congenital anomalies.

METHODS

A cohort of full-term appropriate for-gestational-age neonates subjected to corrective surgery of major congenital anomalies were recruited after gaining weight for at least one week. REE and macronutrient utilization, measured by respiratory quotient (RQ), were assessed by indirect calorimetry using the Deltatrac II Metabolic Monitor ®. Body composition, expressed as fat-free mass (FFM), fat mass (FM) and adiposity defined as percentage of FM (% FM), was measured by air displacement plethysmography using the Pea Pod ®.

RESULTS

Four infants were included at 3 to 5 postnatal weeks. Recommended energy and macronutrient intakes for healthy term infants were provided. Through the study, the median (min-max) REE (Kcal/Kg FFM/d) was 70.8 (60.6-96.1) and RQ was 0.99 (0.72-1.20). Steady increases in both body weight and FFM were associated with initial decrease in FM and adiposity followed by their increase. Low RQ preceded decrease in adiposity.

CONCLUSION

The marked adiposity depletion, not expected during steady weight gain in the postsurgical period, prompts us to report this finding. The subsequent adiposity catch-up was associated with relatively high REE and RQ, suggesting preferential oxidation of carbohydrates and preservation of lipids for fat storage.

Systemic inflammation increases energy expenditure following pediatric cardiopulmonary bypass

OBJECTIVES

To examine the association between cardiopulmonary bypass-related systemic inflammation and resting energy expenditure in pediatric subjects following cardiac surgery.

DESIGN

Single-center, prospective cohort study.

SETTING

Pediatric cardiac critical care unit in Toronto, Canada.

PATIENTS

Children with congenital heart disease undergoing cardiopulmonary bypass surgery.

INTERVENTIONS

Resting energy expenditure was determined by indirect calorimetry and the modified Weir equation, using VO2 and VCO2 measured by in-line respiratory mass spectrometry. Measurements were taken at baseline and 6-hour intervals from separation from cardiopulmonary bypass for a maximum of 72 hours. Plasma interleukin-6, glucose delivery, feeding status, and cardiac output (calculated by Fick equation) were monitored at each resting energy expenditure measurement.

MEASUREMENTS AND MAIN RESULTS

We studied 111 subjects at a median (interquartile range) age of 5.3 months (0.8-10.5 mo), weighing 5.7 kg (3.9-8.1 kg), of whom 88% underwent biventricular repair. Resting energy expenditure decreased from 51 kcal/kg/d to 45 kcal/kg/d during the study period. Resting energy expenditure was positively associated with increased plasma interleukin-6 (estimate variable, 1.76; p = 0.001) and inversely associated with preoperative methylprednisolone use (estimate variable, -6.7; p = 0.003) even after accounting for other predictors. Increase in cardiac output was also associated (estimate variable, 13.7; p < 0.0001) with higher resting energy expenditure.

CONCLUSIONS

Resting energy expenditure ranges between 40 and 60 kcal/kg/d and decreases progressively in children following cardiopulmonary bypass surgery. It is directly associated with increased inflammation and higher cardiac output and inversely associated with anti-inflammatory strategies. Further studies are required to predict the appropriate caloric delivery in this cohort.

How much protein and energy are needed to equilibrate nitrogen and energy balances in ventilated critically ill children?

BACKGROUND & AIMS

Protein and energy requirements in critically ill children are currently based on insufficient data. Moreover, longitudinal measurements of both total urinary nitrogen (TUN) and resting energy expenditure (REE) are lacking. The aim of this study was to investigate how much protein and energy are needed to equilibrate nitrogen and energy balances in ventilated critically ill children on the basis of daily measurements of TUN, REE and protein and energy intakes. Comparisons were made with the guidelines of the American Society for Parenteral and Enteral Nutrition and the Dietary Reference Intakes.

METHODS

Children with an expected duration of mechanical ventilation ≥72 h were prospectively recruited. TUN was measured by chemiluminescence, and REE was measured by indirect calorimetry. Generalised linear models for longitudinal data were used to study the relation between protein intake and nitrogen balance and to calculate the minimum intake of protein needed to achieve nitrogen equilibrium. A similar approach was used for energy. Results were compared to the recommended values.

RESULTS

Based on 402 measurements performed in 74 children (median age: 21 months), the mean TUN was high at 0.20 (95% CI: 0.20, 0.22) g/kg/d and the REE was 55 (95% CI: 54, 57) kcal/kg/d. Nitrogen and energy balances were achieved with 1.5 (95% CI: 1.4, 1.6) g/kg/d of protein and 58 (95% CI: 53, 63) kcal/kg/d for the entire group, but there were differences among children of different ages. Children required more protein and less energy than the Dietary Reference Intakes.

CONCLUSIONS

In critically ill children, TUN was elevated and REE was reduced during the entire period of mechanical ventilation. Minimum intakes of 1.5 g/kg/d of protein and 58 kcal/kg/d can equilibrate nitrogen and energy balances in children up to 4 years old. Older children require more protein.

Variability of resting energy expenditure in infants and young children with intestinal failure-associated liver disease

OBJECTIVE

The aim of the study was to determine, in a cohort of young children with intestinal failure (IF), whether the estimates of basal metabolic rate (BMR) by standard equations can approximate measured resting energy expenditure (REE) by indirect calorimetry (IC).

METHODS

IC was performed using the dilutional canopy technique. REE measurements were compared with standard, age-based estimation equations (World Health Organization) for BMR. Subjects were classified as hypermetabolic (REE > 110% BMR), hypometabolic (REE < 90% BMR), or normal (REE = 90%-110% BMR).

RESULTS

Twenty-eight IF patients (11 girls, 17 boys) had an underlying diagnosis of necrotizing enterocolitis (n = 10) or a congenital gastrointestinal defect (n = 18). Median age was 5.3 months. Median interquartile range (IQR) REE was 46 (42-58) kcal · kg · day. Median (IQR) total energy intake provided 209% (172%-257%) of REE, with parenteral nutrition providing 76% (23%) of total energy intake. REE was variable, with 39% (n = 11) of measurements hypermetabolic, 39% (n = 11) hypometabolic, and the remaining 21% (n = 6) normal. Although REE was well correlated with estimated BMR (r = 0.82, P < 0.0001), estimated BMR was not consistently an adequate predictor of REE. BMR over- or underestimated REE by >10 kcal · kg · day in 15 of 28 (54%) patients. REE was not significantly correlated with severity of liver disease, nutritional status, total energy intake, or gestational age.

CONCLUSIONS

Energy expenditure is variable among children with IF and IF-associated liver disease, with approximately 80% of our cohort exhibiting either hypo- or hypermetabolism. Standard estimation equations frequently do not correctly predict individual REE. Longitudinal studies of energy expenditure and body composition may be needed to guide provision of nutrition regimens.

Validation of the V(max) metabolic cart in a simulated pediatric model

BACKGROUND

The ability to accurately measure resting energy expenditure (REE) using indirect calorimetry, often referred to as the "gold standard" in nutrition needs assessment, is important given the well-established positive correlation between patient outcome and proportion of the nutrition goal met. While many studies have been done to compare various metabolic carts with one another, the literature lacks a large simulator-based validation of any metabolic cart system.

MATERIALS AND METHODS

In the present study, 8 specifically trained staff members independently conducted 10 simulation trials each using the V(max) Encore metabolic analyzer in conjunction with a metabolic calibration system, which simulates patient metabolic activity, to validate the accuracy of the V(max) Encore across a wide range of simulated metabolic conditions. Testing conditions consisted of incremental adjustments in calibrated gas infusion with a consistently set tidal volume and respiratory rate.

RESULTS

There was a strong, statistically significant correlation between the predicted and actual VO2 and VCO2 data (VO2, R (2) = 0.998; VCO2, R (2) = 0.997). In addition, we observed no significant difference between individuals performing these trials (VO2, P = 1.000, F = 0.021, df = 79; VCO2, P = 1.000, F = 0.030, df = 79).

CONCLUSIONS

This study is the first to report on such a wide spectrum of metabolic activity (50-2000 kcal REE) using a calibrated bench model and validates the accuracy, reproducibility, and use of the V(max) Encore metabolic cart.

Accuracy of a simplified equation for energy expenditure based on bedside volumetric carbon dioxide elimination measurement--a two-center study

BACKGROUND & AIMS

Accurate assessment of resting energy expenditure (REE) and metabolic state is essential to optimize nutrient intake in critically ill patients. We aimed to examine the accuracy of a simplified equation for predicting REE using carbon dioxide elimination (VCO2) values.

METHODS

We conducted a two-center study of metabolic data from mechanically ventilated children less than 18 years of age. Mean respiratory quotient (RQ) from the derivation set (n = 72 subjects) was used to modify the Weir equation to obtain a simplified equation based on VCO2 measurements alone. This equation was then applied to subjects at the second institution (validation dataset, n = 94) to predict resting energy expenditure. Bland-Altman analysis was used to assess the agreement between measured REE values, and REE estimated by the new equation as well as the Schofield equation. We also examined the accuracy of the new equation in classifying patients according to their metabolic state.

RESULTS

Mean respiratory quotient (± SD) of 0.89 ± 0.09 in the derivation set was used to obtain a simplified equation, REE (kcal/day) = 5.534*VCO2 (L/min)*1440. In relation to the measured REE in the validation set, the mean bias (limits of agreement) for the REE predicted by this equation was -0.65% (-14.4-13.1%); and the overall diagnostic accuracy for classifying subjects as hypometabolic or hypermetabolic was 84%. Mean bias (limits) of agreement between measured and Schofield equation estimated REE was -0.1% (-40.5-40.7%).

CONCLUSIONS

A simplified metabolic equation using VCO2 values was superior to the standard equation in estimating REE, and provided a reasonably accurate metabolic classification in mechanically ventilated children. In the absence of indirect calorimetry, bedside VCO2 monitoring could provide valuable continuous metabolic information to guide optimal nutrient intake.

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.