Feasibility of Enteral Protein Supplementation in Critically Ill Children

BACKGROUND

We describe the protein type and concentration in standard enteral nutrition (EN) formulas and the effect of protein supplementation on the osmolality of standard formulas. We also aimed to examine factors associated with optimal protein delivery in critically ill children.

METHODS

Protein content and other characteristics of pediatric EN formulas used worldwide were recorded. Factors associated with achievement of recommended protein delivery and tolerance of protein-supplemented formulas were recorded prospectively in a cohort of critically ill children. A range of protein supplement doses was added to 2 standard formulas and water, and the osmolality was recorded by cryoscopy in a bench experiment.

RESULTS

We reviewed 125 formulas used in a multicenter study including sites from >13 countries. A majority of the EN formulas (73.6%) were polymeric, with a nonprotein calorie/nitrogen ratio of 182 ± 66 and protein content of 3.53 ± 2.00 g/100 mL. In the cohort of critically ill children, 28.5% achieved protein intake goal within 4 days, with no intolerance. In addition to optimal protein prescription (P < 0.001), protein supplementation (P = 0.018) and early EN initiation (P = 0.006) were associated with significantly higher odds of achieving goal protein intake. Formulas supplemented with up to 8 g/100 mL polymeric protein had osmolality <450 mOsm/kg.

CONCLUSIONS

The protein content of current pediatric formulas may be inadequate to meet the needs of critically ill children. Protein supplementation of formulas allows early achievement of goal and is likely to be safe.).

Body Composition in Children with Chronic Illness: Accuracy of Bedside Assessment Techniques

OBJECTIVE

To evaluate the accuracy of estimated fat mass and fat-free mass from bedside methods compared with reference methods in children with chronic illnesses.

STUDY DESIGN

Fat mass and fat-free mass values were obtained by skinfold, bioelectrical impedance analysis (BIA), dual-energy x-ray absorptiometry (DXA), and deuterium dilution method in children with spinal muscular atrophy, intestinal failure, and post hematopoietic stem cell transplantation (HSCT). Spearman's correlation and agreement analyses were performed between (1) fat mass values estimated by skinfold equations and by DXA and (2) fat-free mass values estimated by BIA equations and by DXA and deuterium dilution methods. Limits of agreement between estimating and reference methods within ±20% were deemed clinically acceptable.

RESULTS

Fat mass and fat-free mass values from 90 measurements in 56 patients, 55% male, and median age of 11.6 years were analyzed. Correlation coefficients between the skinfold-estimated fat mass values and DXA were 0.93-0.94 and between BIA-estimated fat-free mass values and DXA were 0.92-0.97. Limits of agreement between estimated and DXA values of fat mass and fat-free mass were greater than ±20% for all equations. Correlation coefficients between estimated fat-free mass values and deuterium dilution method in 35 encounters were 0.87-0.91, and limits of agreement were greater than ±20%.

CONCLUSION

Estimated body composition values derived from skinfold and BIA may not be reliable in children with chronic illnesses. An accurate noninvasive method to estimate body composition in this cohort is desirable.

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.

Timing of the initiation of parenteral nutrition in critically ill children

PURPOSE OF REVIEW

To review the current literature evaluating clinical outcomes of early and delayed parenteral nutrition initiation among critically ill children.

RECENT FINDINGS

Nutritional management remains an important aspect of care among the critically ill, with enteral nutrition generally preferred. However, inability to advance enteral feeds to caloric goals and contraindications to enteral nutrition often leads to reliance on parenteral nutrition. The timing of parenteral nutrition initiation is varied among critically ill children, and derives from an assessment of nutritional status, energy requirements, and physiologic differences between adults and children, including higher nutrient needs and lower body reserves. A recent randomized control study among critically ill children suggests improved clinical outcomes with avoiding initiation of parenteral nutrition on day 1 of admission to the pediatric ICU.

SUMMARY

Although there is no consensus on the optimal timing of parenteral nutrition initiation among critically ill children, recent literature does not support the immediate initiation of parenteral nutrition on pediatric ICU admission. A common theme in the reviewed literature highlights the importance of accurate assessment of nutritional status and energy expenditure in deciding when to initiate parenteral nutrition. As with all medical interventions, the initiation of parenteral nutrition should be considered in light of the known benefits of judiciously provided nutritional support with the known risks of artificial, parenteral feeding.

Accuracy of Oxygen Consumption and Carbon Dioxide Elimination Measurements in 2 Breath-by-Breath Devices

BACKGROUND

Although accurate quantification of oxygen consumption (V̇_O2 ) and carbon dioxide elimination (V̇_CO2 ) provides important insights into a patient's nutritional and hemodynamic status, few devices exist to accurately measure these parameters in children. Therefore, we assessed the accuracy and agreement of 2 devices currently on the market using a pediatric in vitro model of gas exchange.

METHODS

We utilized a Huszczuk simulation model, which simulates oxygen consumption and carbon dioxide production using gas dilution, to examine the accuracy of two FDA-cleared respiratory modules (E-COVX and E-sCAiOVX-00). V̇_O2 and V̇_CO2 were set at 20, 40, 60, and 100 mL/min, ranges typical for infant and pediatric patients. Bland-Altman analysis was used to calculate the bias and limits of agreement of each device relative to simulated values for V̇_O2 and V̇_CO2 .

RESULTS

The E-COVX mean percentage bias (limits of agreement) was -26.3% (-36.1 to -16.6%) and -39.3% (-47.5 to -31.1%) for V̇_O2 and V̇_CO2 , respectively. The mean bias (limits of agreement) for the E-aCAiOVX-00 was -0.5% (-13.3 to 12.3%) and -6.0% (-13.8 to 1.7%) for V̇_O2 and V̇_CO2 , respectively.

CONCLUSIONS

The E-COVX demonstrated bias and limits of agreement that were not clinically acceptable; therefore, application of this module to pediatric patients would not be recommended. The new module, E-sCAiOVX, demonstrated acceptable bias and limits of agreement for the V̇_O2 and V̇_CO2 in the range 40-100 mL/min (which corresponds to patients in the range of ∼5-16 kg).

Optimal nutrition therapy in paediatric critical care in the Asia-Pacific and Middle East: a consensus

BACKGROUND AND OBJECTIVES

Current practices and available resources for nutrition therapy in paediatric intensive care units (PICUs) in the Asia Pacific-Middle East region are expected to differ from western countries. Existing guidelines for nutrition management in critically ill children may not be directly applicable in this region. This paper outlines consensus statements developed by the Asia Pacific-Middle East Consensus Working Group on Nutrition Therapy in the Paediatric Critical Care Environment. Challenges and recommendations unique to the region are described.

METHODS AND STUDY DESIGN

Following a systematic literature search from 2004-2014, consensus statements were developed for key areas of nutrient delivery in the PICU. This review focused on evidence applicable to the Asia Pacific-Middle East region. Quality of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development and Evaluation approach.

RESULTS

Enteral nutrition (EN) is the preferred mode of nutritional support. Feeding algorithms that optimize EN should be encouraged and must include: assessment and monitoring of nutritional status, selection of feeding route, time to initiate and advance EN, management strategies for EN intolerance and indications for using parenteral nutrition (PN). Despite heterogeneity in nutritional status of patients, availability of resources and diversity of cultures, PICUs in the region should consider involvement of dieticians and/or nutritional support teams.

CONCLUSIONS

Robust evidence for several aspects of optimal nutrition therapy in PICUs is lacking. Nutritional assessment must be implemented to document prevalence and impact of malnutrition. Nutritional support must be given greater priority in PICUs, with particular emphasis in optimizing EN delivery.

Gastric Emptying in Critically Ill Children

BACKGROUND

Delayed gastric emptying (GE) impedes enteral nutrient (EN) delivery in critically ill children. We examined the correlation between (a) bedside EN intolerance assessments, including gastric residual volume (GRV); (b) delayed GE; and (c) delayed EN advancement.

MATERIALS AND METHODS

We prospectively enrolled patients ≥1 year of age, eligible for gastric EN and without contraindications to acetaminophen. Gastric emptying was determined by the acetaminophen absorption test, specifically the area under the curve at 60 minutes (AUC₆₀). Slow EN advancement was defined as delivery of <50% of the prescribed EN 48 hours after study initiation. EN intolerance assessments (GRV, abdominal distension, emesis, loose stools, abdominal discomfort) were recorded.

RESULTS

We enrolled 20 patients, median 11 years (4.4-15.5), 50% male. Sixteen (80%) patients had delayed GE (AUC₆₀ <600 mcg·min/mL) and 7 (35%) had slow EN advancement. Median GRV (mL/kg) for patients with delayed vs normal GE was 0.43 (0.113-2.188) vs 0.89 (0.06-1.91), P = .9635. Patients with slow vs rapid EN advancement had median GRV (mL/kg) of 1.02 mL/kg (0.20-3.20) vs 0.27 mL/kg (0.06-1.62), P = .3114, and frequency of altered EN intolerance assessments of 3/7 (42.9%) vs 5/13 (38.5%), P = 1. Median AUC₆₀ for patients with slow vs rapid EN advancement was 91.74 mcg·min/mL (53.52-143.1) vs 449.5 mcg·min/mL (173.2-786.5), P = .0012.

CONCLUSIONS

A majority of our study cohort had delayed GE. Bedside EN intolerance assessments, particularly GRV, did not predict delayed GE or rate of EN advancement. Delayed gastric emptying predicted slow EN advancement. Novel tests for delayed GE and EN intolerance are needed.

Nutrient delivery in mechanically ventilated surgical patients in the pediatric critical care unit

PURPOSE

Inadequate nutrient intake is associated with poor outcomes in critically ill children. We examined macronutrient delivery in surgical patients in the pediatric intensive care unit (PICU).

METHODS

In a prospective international cohort study of mechanically ventilated children (1month to 18years), we recorded adequacy of cumulative nutrient delivery in the PICU. Surgical patients enrolled in this study were included in the current analysis. Protein intake <60% of the prescribed goal was deemed inadequate.

RESULTS

Five hundred nineteen surgical patients, 45% female, median age 2years (IQR 0.5, 8), BMI z score -0.26, with 9-day median PICU stay and 60-day mortality 5.8% were enrolled. Three hundred forty-one (66%) patients received enteral nutrition (EN), and median time of initiation was PICU day 2. EN delivery was interrupted in 68% of these patients for a median duration of 9hours. Median enteral protein delivery was <15% of the prescribed goal and was <60% in two-thirds of the cohort. Patients with inadequate enteral protein delivery had longer time to EN initiation (p<0.001) and longer duration of EN interruptions (p<0.001) compared to those with adequate delivery.

CONCLUSION

Enteral protein delivery in critically ill pediatric surgical patients is inadequate. Early EN initiation and minimizing interruptions may increase protein delivery and potentially improve outcomes in this population.

LEVEL OF EVIDENCE

I.

TYPE OF STUDY

Prospective study.

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.

Energy and Protein Delivery in Overweight and Obese Children in the Pediatric Intensive Care Unit

BACKGROUND

Early and optimal energy and protein delivery have been associated with improved clinical outcomes in the pediatric intensive care unit (PICU). Overweight and obese children in the PICU may be at risk for suboptimal macronutrient delivery; we aimed to describe macronutrient delivery in this cohort.

METHODS

We performed a retrospective study of PICU patients ages 2-21 years, with body mass index (BMI) ≥85th percentile and >48 hours stay. Nutrition variables were extracted regarding nutrition screening and assessment, energy and protein prescription, and delivery.

RESULTS

Data from 83 patient encounters for 52 eligible patients (52% male; median age 9.6 [5-15] years) were included. The study cohort had a longer median PICU length of stay (8 vs 5 days, P < .0001) and increased mortality rate (6/83 vs 182/5572, P = .045) than concurrent PICU patient encounters. Detailed nutrition assessment was documented for 60% (50/83) of patient encounters. Energy expenditure was estimated primarily by predictive equations. Stress factor >1.0 was applied in 44% (22/50). Median energy delivered as a percentage of estimated requirements by the Schofield equation was 34.6% on day 3. Median protein delivered as a percentage of recommended intake was 22.1% on day 3.

CONCLUSIONS

The study cohort had suboptimal nutrition assessments and macronutrient delivery during their PICU course. Mortality and duration of PICU stay were greater when compared with the general PICU population. Nutrition assessment, indirect calorimetry-guided energy prescriptions, and optimizing the delivery of energy and protein must be emphasized in this cohort. The impact of these practices on clinical outcomes must be investigated.

International Pediatric Otolaryngology Group (IPOG) consensus recommendations: Routine peri-operative pediatric tracheotomy care

OBJECTIVES

To develop consensus recommendations for peri-operative tracheotomy care in pediatric patients.

METHODS

Expert opinion by the members of the International Pediatric Otolaryngology Group (IPOG). The mission of the IPOG is to develop expertise-based consensus recommendations for the management of pediatric otolaryngologic disorders with the goal of improving patient care. The consensus recommendations herein represent the first publication by the group.

RESULTS

Consensus recommendations including pre-operative, intra-operative, and post-operative considerations, as well as sedation and nutrition management are described. These recommendations are based on the collective opinion of the IPOG members and are targeted to (i) otolaryngologists who perform tracheotomies on pediatric patients, (ii) intensivists who are involved in the shared-care of these patients, and (iii) allied health professionals.

CONCLUSION

Pediatric peri-operative tracheotomy care consensus recommendations are aimed at improving patient-centered care in this patient population.

Nutritional status as a predictor of duration of mechanical ventilation in critically ill children

OBJECTIVES

Critically ill children admitted to the pediatric intensive care unit (PICU) often are malnourished. The aim of this study was to determine the role of nutritional status on admission as a predictor of the duration of mechanical ventilation in critically ill children.

METHODS

This was a single-center, prospective cohort study, including consecutive children (ages 1 mo to 15 y) admitted to a PICU. Demographic characteristics, clinical characteristics, and nutritional status were recorded and patients were followed up until hospital discharge. Nutritional status was evaluated by anthropometric parameters and malnutrition was considered if the Z-scores for the parameters were ≤-2. Adjusted Cox's regression analysis was used to determine the association between nutritional status and duration of mechanical ventilation.

RESULTS

In all, 72 patients were included. The prevalence of malnutrition was 41.2%, according to height-for-age Z-score, 18.6% according to weight-for-height Z-score, and 22.1% according body mass index-for-age Z-score. Anthropometrical parameters that predicted the duration of mechanical ventilation were weight-for-age (hazard ratio [HR], 2.73; 95% confidence interval [CI], 1.44-5.18); height-for-age (HR, 2.49; 95% CI, 1.44-4.28); and upper arm muscle area-for-age (HR, 5.22; 95% CI, 1.19-22.76).

CONCLUSION

Malnutrition, based on a variety of anthropometric variables, was associated with the duration of mechanical ventilation in this cohort of critically ill children. Assessment of nutritional status by anthropometry should be performed on admission to the PICU to allow targeted nutritional rehabilitation for the subset of children with existing malnutrition.

Survey of contemporary feeding practices in critically ill children in the Asia-Pacific and the Middle East

BACKGROUND AND OBJECTIVES

Nutrition is a fundamental component of care of critically ill children. Determining variation in nutritional practices within paediatric intensive care units (PICUs) allows for review and improvement of nutrition practices.

METHODS AND STUDY DESIGN

The aim was to survey the nutrition practices and perspectives of paediatric intensivists and dieticians in Asia-Pacific and the Middle East. A questionnaire was developed to collect data on (1) the respondent's and institution's characteristics, (2) nutritional assessments and nutrient delivery practices, and (3) the perceived importance and barriers to optimal enteral feeding in the PICU.

RESULTS

We analysed 47 responses from 35 centres in 18 different countries. Dedicated dietetic services were only present in 13 (37%) centres and regular nutrition assessments were conducted in only 12 (34%) centres. In centres with dedicated dieticians, we found greater use of carbohydrate, fat additives and special formulas. Two thirds [31 (66%)] of respondents used total fluids to estimate energy requirements. Only 11 (31%) centres utilized feeding protocols. These centres had higher use of small bowel feeding, acid suppressants, laxatives and gastric residual volume thresholds. When dealing with feed intolerance, they were also more likely to start a motility agent. There was also a lack of consensus on when feeding should start and the use of adjuncts.

CONCLUSIONS

Nutrition practices and barriers are unique in Asia-Pacific and the Middle East and strongly reflect a lack of dietetic services. Future effort should focus on developing a uniform approach on nutrition practices to drive paediatric critical care nutrition research in these regions.

A Comparison of Carbon Dioxide Elimination Measurements Between a Portable Indirect Calorimeter and Volumetric Capnography Monitor: An In Vitro Simulation

BACKGROUND

Gas exchange measurements for carbon dioxide elimination (V̇CO2 ) and oxygen consumption (V̇O2 ) have been used to derive resting energy expenditure and guide energy prescription. Volumetric capnography is used in intensive care units and provides V̇CO2 measurements that could be used for titrating respiratory and nutritional support. We have recently suggested that measuring V̇CO2 may be sufficient to obtain a reasonable estimate of energy expenditure. However, data describing the accuracy of gas exchange measurement devices are limited.

METHODS

We used an in vitro simulation model to test the accuracy of gas exchange measurements by 2 devices: the CCM Express indirect calorimeter and the NM3, a volumetric capnography monitor. A Huszczuk gas injection system combined with a high-fidelity lung simulator was used to simulate V̇O2 and V̇CO2 values in the pediatric and adult range. Bland-Altman analysis was used to examine the agreement between the measured and simulated values across a range of tidal volumes and gas exchange values. Additionally, agreement between the 2 devices was examined.

RESULTS

During the adult simulation with the CCM Express, the mean bias (95% CI) for V̇CO2 values was -12.6% (-16.4 to -8.8%) and -17.5% (-19.9 to -15.1%) for V̇O2 values. For the pediatric simulation with the CCM Express, mean bias for V̇O2 was -14.7% (-16.4 to -13.0%) and V̇CO2 was -10.9% (-13.5 to -8.3%). For the adult and pediatric simulations with the NM3, the bias for V̇CO2 was -8.2% (-15.7 to -0.7%) and -8.3% (-19.4 to -2.8%), respectively. Between the 2 devices, the mean bias was -4.4% (-10.2 to 1.3%) and -2.3% (-11.4 to 6.8%) for the adult and pediatric V̇CO2 simulations, respectively.

CONCLUSIONS

Currently available portable gas exchange monitors demonstrated acceptable agreement with reference V̇O2 and V̇CO2 values in an in vitro simulation. The devices demonstrated good agreement with each other.

Impact of Individualized Diet Intervention on Body Composition and Respiratory Variables in Children With Respiratory Insufficiency: A Pilot Intervention Study

OBJECTIVES

Diet modification may improve body composition and respiratory variables in children with respiratory insufficiency. Our objective was to examine the effect of an individualized diet intervention on changes in weight, lean body mass, minute ventilation, and volumetric CO2 production in children dependent on long-term mechanical ventilatory support.

DESIGN

Prospective, open-labeled interventional study.

SETTING

Study subjects' homes.

PATIENTS

Children, 1 month to 17 years old, dependent on at least 12 hr/d of transtracheal mechanical ventilatory support.

INTERVENTIONS

Twelve weeks of an individualized diet modified to deliver energy at 90-110% of measured energy expenditure and protein intake per age-based guidelines.

MEASUREMENTS AND MAIN RESULTS

During a multidisciplinary home visit, we obtained baseline values of height and weight, lean body mass percent by bioelectrical impedance analysis, actual energy and protein intake by food record, and measured energy expenditure by indirect calorimetry. An individualized diet was then prescribed to optimize energy and protein intake. After 12 weeks on this interventional diet, we evaluated changes in weight, height, lean body mass percent, minute ventilation, and volumetric CO2 production. Sixteen subjects, mean age 9.3 years (SD, 4.9), eight male, completed the study. For the diet intervention, a majority of subjects required a change in energy and protein prescription. The mean percentage of energy delivered as carbohydrate was significantly decreased, 51.7% at baseline versus 48.2% at follow-up, p = 0.009. Mean height and weight increased on the modified diet. Mean lean body mass percent increased from 58.3% to 61.8%. Minute ventilation was significantly lower (0.18 L/min/kg vs 0.15 L/min/kg; p = 0.04), and we observed a trend toward lower volumetric CO2 production (5.4 mL/min/kg vs 5.3 mL/min/kg; p = 0.06) after 12 weeks on the interventional diet.

CONCLUSIONS

Individualized diet modification is feasible and associated with a significant decrease in minute ventilation, a trend toward significant reduction in CO2 production, and improved body composition in children on long-term mechanical ventilation. Optimization of respiratory variables and lean body mass by diet modification may benefit children with respiratory insufficiency in the ICU.

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.

Metabolic assessment and individualized nutrition in children dependent on mechanical ventilation at home

OBJECTIVE

To evaluate the nutritional and metabolic status and body composition of children on long-term mechanical ventilation using a home-based model.

STUDY DESIGN

Children on home mechanical ventilation, for at least 12 hours a day, were eligible. We performed anthropometry, bioelectrical impedance analysis (BIA), actual energy intake (AEI), and indirect calorimetry in the subject's home. Agreement between measured energy expenditure (MEE) from indirect calorimetry, and estimated energy expenditure by the Schofield equation and a novel volumetric carbon dioxide production-based equation was examined. Agreement between fat mass estimates from anthropometry and BIA was examined and compared with population norms.

RESULTS

We enrolled 20 children, 11 (55%) male; mean age 8.4 years (SD 4.8). Mean weight for age z-score was -0.26 (SD 1.48); 9/20 had z-scores <-1 or >+1. Thirteen were underfed (AEI:MEE <90%) or overfed (AEI:MEE >110%); 11 of 19 had protein intake that was less than recommended by guidelines. Fifteen subjects were hypo- or hypermetabolic. Mean (SD) fat mass % was 33.6% (8.6) by anthropometry, which was significantly greater than matched population norms (mean 23.0%, SD 6.1, P < .001). The estimated energy expenditure by a volumetric carbon dioxide production-based equation was in stronger agreement with the MEE than the Schofield equation (mean bias 0.06%, limits -15.98% to 16.16% vs mean bias -1.31%, limits -74.3% to 72%, respectively). BIA and anthropometric fat mass values were not in agreement.

CONCLUSION

A majority of children on home ventilation are characterized by malnutrition, altered metabolic status, and suboptimal macronutrient intake, in particular low protein intake. A multidisciplinary home-based model facilitates individualized energy and protein delivery and may improve outcomes in this cohort.

Nutritional outcomes in survivors of congenital diaphragmatic hernia (CDH)-factors associated with growth at one year

BACKGROUND

Malnutrition is prevalent among congenital diaphragmatic hernia (CDH) survivors. We aimed to describe the nutritional status and factors that impact growth over the 12-months following discharge from the pediatric intensive care unit (PICU) in this cohort.

METHODS

CDH survivors, who were discharged from the PICU from 2000 to 2010 with follow-up of at least 12months, were included. Nutritional intake, anthropometric, and clinical variables were recorded. Multivariable linear regression was used to determine factors associated with weight-for-age Z-scores (WAZ) at 12months.

RESULTS

Data from 110 infants, 67% male, 50% patch repair, were analyzed. Median (IQR) WAZ for the cohort was -1.4 (-2.4 to -0.3) at PICU discharge and -0.4 (-1.3 to 0.2) at 12-months. The percentage of infants with significant malnutrition (WAZ<-2) decreased from 26% to 8.5% (p<0.001). Patch repair (p=0.009), protein intake<2.3g/kg/day (p=0.014), and birth weight (BW)<2.5kg (p<0.001) were associated with lower WAZ at 12-months.

CONCLUSIONS

CDH survivors had a significantly improved nutritional status in the 12-months after PICU discharge. Patch repair, lower BW, and inadequate protein intake were significant predictors of lower WAZ at 12-months. A minimum protein intake in the PICU of 2.3g/kg/day was essential to ensure optimal growth in this cohort.

Carbon dioxide elimination and oxygen consumption in mechanically ventilated children

BACKGROUND

Accurate measurement of carbon dioxide elimination (V̇CO2 ) and oxygen consumption (V̇O2 ) at the bedside may help titrate nutritional and respiratory support in mechanically ventilated patients. Continuous V̇CO2 monitoring is now available with many ventilators. However, because normative data are sparsely available in the literature, we aimed to describe the range of V̇CO2 and V̇O2 values observed in mechanically ventilated children. We also aimed to examine the characteristics of V̇CO2 values that are associated with standard steady state (5-min period when V̇CO2 and V̇O2 variability are < 10%).

METHODS

Mechanically ventilated patients who underwent indirect calorimetry testing were eligible for inclusion, and subjects who achieved standard steady state were included. Normalized V̇CO2 and V̇O2 values (mL/kg/min) were modeled against subject height, and correlation coefficients were computed to quantify the goodness of fit. A steady-state definition using only V̇CO2 was developed (V̇CO2 variability of < 5% for a 5-min period) and tested against standard steady state using sensitivity and specificity.

RESULTS

Steady-state data from 87 indirect calorimetry tests (in 70 subjects) were included. For age groups < 0.5, 0.5-8, and > 8 y, the mean V̇CO2 values were 7.6, 5.8, and 3.5 mL/kg/min. Normalized V̇CO2 and V̇O2 values were inversely related to subject height and age. The relationships between normalized gas exchange values and height were demonstrated by the models: V̇CO2 = 115 × (height in cm)(-0.71) (R = 0.61, P < .001) and V̇O2 = 130 × (height in cm)(-0.72) (R = 0.61, P < .001). Steady-state V̇CO2 predicted standard steady state (sensitivity of 0.84, specificity of 1.0, P < .01).

CONCLUSIONS

V̇CO2 and V̇O2 measurements correlated with subject height and age. Smaller and younger subjects produced larger amounts of CO2 and consumed more O2 per unit of body weight. The use of a 5-min period when V̇CO2 varied by < 5% predicted standard steady state. Our observations may facilitate greater utility of V̇CO2 at the bedside in the pediatric ICU and thereby extend the benefits of metabolic monitoring to a larger group of patients.

Nutrition algorithms and bedside nutrient delivery practices in pediatric intensive care units: an international multicenter cohort study

BACKGROUND

Enteral nutrition (EN) delivery is associated with improved outcomes in critically ill patients. We aimed to describe EN practices, including details of algorithms and individual bedside practices, in pediatric intensive care units (PICUs).

METHODS

Available EN algorithm details from 31 international PICUs were obtained. Daily nutrient intake data from 524 mechanically ventilated patients, 1 month to 18 years old, were prospectively documented, including EN delivery, adjunct therapies, and energy prescription. Practices associated with higher percentage adequacy of EN delivery were determined by regression analysis.

RESULTS

Nine EN algorithms were available. All algorithms defined advancement and EN intolerance; 7 of 9 defined intolerance by gastric residual volume; 3 of 9 recommended nutrition screening and fasting guidelines. Few elements were in agreement with the American Society for Parenteral and Enteral Nutrition and the European Society of Paediatric Gastroenterology, Hepatology, and Nutrition guidelines. Of the 341 patients who received EN exclusively 32.9% received ≥66.6% of prescribed energy on day 7. Percentage adequacy of EN delivered was inversely associated with days to EN initiation (-8.92; P < .001) and hours per EN interruption (-1.65; P = .001) and was not associated with the use of algorithms, promotility agents, or postpyloric feeding.

CONCLUSIONS

A minority of PICUs employ EN algorithms; recommendations were variable and not in agreement with national guidelines. Optimal EN delivery was achieved in less than one-third of our cohort. EN adjunct therapies were not associated with increased EN delivery. Studies aimed at promoting early EN and decreasing interruptions may optimize energy delivery in the PICU.

Current applications of metabolic monitoring in the pediatric intensive care unit

Delivery of adequate nutrients during illness to counteract the metabolic stress response and facilitate healing and tissue repair is an important goal in the care of critically ill children. With recent advances in technology, accurate minute-to-minute gas exchange and energy expenditure measurements are now available in intensive care units. The bedside availability of these devices may allow a titrated approach to energy delivery for patients, ushering in a new era of individualized nutrition therapy. Basic concepts, available monitoring devices, indications, pitfalls, and bedside application of metabolic monitoring are discussed in this article.

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.

Influence of obesity on clinical outcomes in hospitalized children: a systematic review

IMPORTANCE

Obesity is prevalent among hospitalized children. Knowledge of the relationship between obesity and outcomes in hospitalized children will enhance nutrition assessment and provide opportunities for interventions.

OBJECTIVE

To systematically review the existing literature concerning the impact of obesity on clinical outcomes in hospitalized children.

EVIDENCE ACQUISITION

PubMed, Web of Science, and EMBASE databases were searched for studies of hospitalized children aged 2 to 18 years with identified obesity and at least 1 of the following clinical outcomes: all-cause mortality, incidence of infections, and length of hospital stay. Cohort and case-control studies were included. Cross-sectional studies, studies of healthy children, and those without defined criteria for classifying weight status were excluded. The Newcastle-Ottawa Scale was used to assess study quality.

RESULTS

Twenty-eight studies (26 retrospective; 24 cohort and 4 case-control) were included. Of the 21 studies that included mortality as an outcome, 10 reported a significant positive relationship between obesity and mortality. The incidence of infections was assessed in 8 of the 28 studies; 2 reported significantly more infections in obese compared with nonobese patients. Of the 11 studies that examined length of stay, 5 reported significantly longer lengths of hospital stay for obese children. Fifteen studies (53%) had a high quality score. Larger studies observed significant relationships between obesity and outcomes. Studies of critically ill, oncologic or stem cell transplant, and solid organ transplant patients showed a relationship between obesity and mortality.

CONCLUSIONS AND RELEVANCE

The available literature on the relationship between obesity and clinical outcomes is limited by subject heterogeneity, variations in criteria for defining obesity, and outcomes examined. Childhood obesity may be a risk factor for higher mortality in hospitalized children with critical illness, oncologic diagnoses, or transplants. Further examination of the relationship between obesity and clinical outcomes in this subgroup of hospitalized children is needed.

Defining pediatric malnutrition: a paradigm shift toward etiology-related definitions

Lack of a uniform definition is responsible for underrecognition of the prevalence of malnutrition and its impact on outcomes in children. A pediatric malnutrition definitions workgroup reviewed existing pediatric age group English-language literature from 1955 to 2011, for relevant references related to 5 domains of the definition of malnutrition that were a priori identified: anthropometric parameters, growth, chronicity of malnutrition, etiology and pathogenesis, and developmental/ functional outcomes. Based on available evidence and an iterative process to arrive at multidisciplinary consensus in the group, these domains were included in the overall construct of a new definition. Pediatric malnutrition (undernutrition) is defined as an imbalance between nutrient requirements and intake that results in cumulative deficits of energy, protein, or micronutrients that may negatively affect growth, development, and other relevant outcomes. A summary of the literature is presented and a new classification scheme is proposed that incorporates chronicity, etiology, mechanisms of nutrient imbalance, severity of malnutrition, and its impact on outcomes. Based on its etiology, malnutrition is either illness related (secondary to 1 or more diseases/injury) or non-illness related, (caused by environmental/behavioral factors), or both. Future research must focus on the relationship between inflammation and illness-related malnutrition. We anticipate that the definition of malnutrition will continue to evolve with improved understanding of the processes that lead to and complicate the treatment of this condition. A uniform definition should permit future research to focus on the impact of pediatric malnutrition on functional outcomes and help solidify the scientific basis for evidence-based nutrition practices.

Systematic review of the influence of energy and protein intake on protein balance in critically ill children

OBJECTIVE

To examine the influence of protein and energy intakes on protein balance in children receiving mechanical ventilation in the pediatric intensive care unit.

STUDY DESIGN

We hypothesized that higher energy and protein intakes are correlated with positive protein balance. We performed a systematic literature search to identify studies reporting protein balance in children requiring mechanical ventilation. Factors contributing to protein balance, including protein and energy intake, age, illness severity, study design, and feeding routes, were analyzed using a qualitative approach.

RESULTS

Nine studies met the entry criteria and were included in the final analysis. Positive nitrogen balance was reported in 6 of the studies, with a wide range of associated energy and protein intakes. Measures of central tendency for daily energy and protein intakes were significantly correlated with positive protein balance. A minimum intake of 57 kcal/kg/day and 1.5 g protein/kg/day were required to achieve positive protein balance.

CONCLUSION

We found a correlation between higher energy and protein intakes and achievement of positive protein balance in children receiving mechanical ventilation in the pediatric intensive care unit. However, there is a paucity of interventional studies, and a variety of protocols have been used to determine nitrogen balance. Larger clinical trials with uniform methodology are needed to further examine the effect of energy and protein intake on protein balance, lean body mass, and clinical outcomes in children on mechanical ventilation.

Resting energy expenditure after Fontan surgery in children with single-ventricle heart defects

BACKGROUND

Data on resting energy expenditure (REE) and oxygen consumption (VO(2)) after pediatric cardiopulmonary bypass (CPB) will facilitate optimal nutrient prescription.

METHODS

The authors measured continuous REE and VO(2), using an in-line indirect calorimetery (IC) in 30 consecutive children with single-ventricle physiology immediately after Fontan surgery. REE during steady state at 8 hours after surgery was compared with standard equation-estimated energy expenditure (EEE). Patients were classified into 3 groups: hypermetabolic (measured REE [MREE]/EEE ratio >1.2), hypometabolic (MREE/EEE ratio <0.8), and normometabolic (MREE/EEE ratio 0.8-1.2). Demographic, anthropometric, and perioperative clinical characteristics were examined for their correlation with metabolic status.

RESULTS

In 26 of 30 patients with completed IC, mean REE at 8 hours after surgery was 57 ± 20 kcal/kg/d, and mean VO(2) was 110 ± 35 mL/min. Mean values of VO(2) and REE did not change within the first 24 hours after surgery. There was poor correlation between MREE at 8 hours and the EEE using the World Health Organization equation (r = 0.32, P = .11). Most patients (n = 19, 73%) were either normometabolic or hypometabolic. Lack of hypermetabolism was significantly associated with higher intraoperative serum lactate level and positive fluid balance compared with the rest of the group.

CONCLUSIONS

The authors report a low prevalence of hypermetabolism in children with single-ventricle defects after Fontan surgery. Measured REE had poor correlation with equation-estimated energy expenditure in a majority of the cohort. The absence of increased energy expenditure after CPB will influence energy prescription in this group.

Accuracy of abbreviated indirect calorimetry protocols for energy expenditure measurement in critically ill children

BACKGROUND

Accurate measurement of resting energy expenditure (REE) using indirect calorimetry (IC) facilitates optimal energy prescription. Steady-state (SS) REE obtained using a 5-minute protocol (SS5) has been used as a surrogate for 24-hour REE measurement. However, SS5 conditions are difficult to achieve in critically ill children on mechanical ventilatory support.

METHODS

The authors prospectively examined factors associated with successful IC testing using the standard SS5 protocol in mechanically ventilated children. They examined the agreement of REE between SS5 and 2 abbreviated SS protocols: 4-minute (SS4) and 3-minute (SS3) protocols as well as the Schofield prediction equation, using Bland-Altman analysis.

RESULTS

IC testing (n = 45) was completed in 34 children. SS was achieved during 25 (56%), 31 (69%), and 42 (93%) tests, using the SS5, SS4, and SS3 protocols, respectively. Intratest variability in respiratory rate, endotracheal tube leak, and inspiratory time was associated with failed IC by the SS5 protocol. The mean bias (limits of agreement) for REE was 2.8 (-47 to 65), 5.8 (-71 to 72), and -127 (-418 to 1176) kcal/d using SS4, SS3, and Schofield, respectively. A stronger agreement was observed when means of all abbreviated SS REE values during a 30-minute test were used.

CONCLUSION

In mechanically ventilated children, 4-minute and 3-minute SS protocols allowed REE measurements to be obtained in most patients with reasonable accuracy. Abbreviated protocols may decrease the need to rely on inaccurate equations when assessing energy expenditure in children who fail IC testing by standard SS criteria.

Challenges to optimal enteral nutrition in a multidisciplinary pediatric intensive care unit

OBJECTIVE

To describe nutrient intake in critically ill children, identify risk factors associated with avoidable interruptions to enteral nutrition (EN), and highlight opportunities to improve enteral nutrient delivery in a busy tertiary pediatric intensive care unit (PICU). Design, Setting, and Measurements: Daily nutrient intake and factors responsible for avoidable interruptions to EN were recorded in patients admitted to a 29-bed medical and surgical PICU over 4 weeks. Clinical characteristics, time to reach caloric goal, and parenteral nutrition (PN) use were compared between patients with and without avoidable interruptions to EN.

RESULTS

Daily record of nutrient intake was obtained in 117 consecutive patients (median age, 7 years). Eighty (68%) patients received EN (20% postpyloric) for a total of 381 EN days (median, 2 days). Median time to EN initiation was less than 1 day. However, EN was subsequently interrupted in 24 (30%) patients at an average of 3.7 +/- 3.1 times per patient (range, 1-13), for a total of 88 episodes accounting for 1,483 hours of EN deprivation in this cohort. Of the 88 episodes of EN interruption, 51 (58%) were deemed as avoidable. Mechanically ventilated subjects were at the highest risk of EN interruptions. Avoidable EN interruption was associated with increased reliance on PN and impaired ability to reach caloric goal.

CONCLUSIONS

EN interruption is common and frequently avoidable in critically ill children. Knowledge of existing barriers to EN such as those identified in this study will allow appropriate interventions to optimize nutrition provision in the PICU.

Nutritional deficiencies during critical illness

A significant proportion of critically ill children admitted to the pediatric intensive care unit (PICU) present with nutritional deficiencies. Malnourished hospitalized patients have a higher rate of complications, increased mortality, longer length of hospital stay, and increased hospital costs. Critical illness may further contribute to nutritional deteriorate with poor outcomes. Younger age, longer duration of PICU stay, congenital heart disease, burn injury, and need for mechanical ventilation support are some of the factors that are associated with worse nutritional deficiencies. Failure to estimate energy requirements accurately, barriers to bedside delivery of nutrients, and reluctance to perform regular nutritional assessments are responsible for the persistence and delayed detection of malnutrition in this cohort.

Cumulative energy imbalance in the pediatric intensive care unit: role of targeted indirect calorimetry

INTRODUCTION

Failure to accurately estimate energy requirements may result in underfeeding or overfeeding. In this study, a dedicated multidisciplinary nutrition team measured energy expenditure in critically ill children.

METHODS

Steady-state indirect calorimetry was used to obtain measured resting energy expenditure, which was compared with equation-estimated energy expenditure and the total energy intake for each subject. The children's metabolic status was examined in relation to standard clinical characteristics.

RESULTS

Sixteen measurements were performed in 14 patients admitted to the multidisciplinary pediatric intensive care unit over a period of 12 months. Mean age of subjects in this cohort was 11.2 years (range 1.6 months to 32 years) and included 7 males and 7 postoperative patients. Altered metabolism was detected in 13 of 14 subjects and in 15 of 16 (94%) measurements. There was no correlation between the metabolic status of subjects and their clinical characteristics. Average daily energy balance was 200 kcal/d (range -518 to +859 kcal/d). Agreement between measured resting energy expenditure and equation-estimated energy expenditure was poor, with mean bias of 72.3 +/- 446 kcal/d (limits of agreement -801.9 to + 946.5 kcal/d).

CONCLUSIONS

A disparity was observed between equation-estimated energy expenditure, measured resting energy expenditure, and total energy intake, with a high incidence of underfeeding or overfeeding. A wide range of metabolic alterations were recorded, which could not be accurately predicted using standard clinical characteristics. Targeted indirect calorimetry on high-risk patients selected by a dedicated nutrition team may prevent cumulative excesses and deficits in energy balance.

Potential drug sequestration during extracorporeal membrane oxygenation: results from an ex vivo experiment

OBJECTIVE

Using an ex vivo simulation model we set out to estimate the amount of drug lost due to sequestration within the extracorporeal circuit over time.

DESIGN

Simulated closed-loop extracorporeal membrane oxygenation (ECMO) circuits were prepared using a 1.5-m2 silicone membrane oxygenator. Group A consisted of heparin, dopamine, ampicillin, vancomycin, phenobarbital and fentanyl. Group B consisted of epinephrine, cefazolin, hydrocortisone, fosphenytoin and morphine. Drugs were tested in crystalloid and blood-primed circuits. After administration of a one-time dose of drugs in the priming fluid, baseline drug concentrations were obtained (P0). A simultaneous specimen was stored for stability testing at 24 h (P4). Serial post-membrane drug concentrations were then obtained at 30 min (P1), 3 h (P2) and 24 h (P3) from circuit fluid.

MEASUREMENTS AND RESULTS

One hundred and one samples were analyzed. At the end of 24 h in crystalloid-primed circuits, 71.8% of ampicillin, 96.7% of epinephrine, 17.6% of fosphenytoin, 33.3% of heparin, 17.5% of morphine and 87% of fentanyl was lost. At the end of 24 h in blood-primed extracorporeal circuits, 15.4% of ampicillin, 21% of cefazolin, 71% of voriconazole, 31.4% of fosphenytoin, 53.3% of heparin and 100% of fentanyl was lost. There was a significant decrease in overall drug concentrations from 30 min to 24 h for both crystalloid-primed circuits (p = 0.023) and blood-primed circuits (p = 0.04).

CONCLUSIONS

Our ex vivo study demonstrates serial losses of several drugs commonly used during ECMO therapy. Therapeutic concentrations of fentanyl, voriconazole, antimicrobials and heparin cannot be guaranteed in patients on ECMO.

Mechanical ventilation in children with acute respiratory failure

PURPOSE OF REVIEW

Acute respiratory failure requiring mechanical ventilation continues to contribute to mortality and affect long-term functional outcomes in patients admitted to the pediatric intensive care unit (ICU). Studies in adults with acute respiratory distress syndrome (ARDS) far outnumber those conducted in the pediatric age group, and pediatric intensivists are left with the task of carefully selecting and critically appraising relevant adult data and extrapolating results to their domain of practice.

RECENT FINDINGS

The recent ARDSNet study reinforces the use of low tidal volumes. Administration of surfactant is safe, but once again its beneficial effect was not sustained in a randomized trial. Surfactant proteins A and D have been shown to be of prognostic value in cases of acute lung injury. The effect of inhaled nitric oxide (NO) in patients with ARDS can be enhanced by aggressive lung recruitment strategies such as can be achieved using high-frequency oscillatory ventilation (HFOV). A recent adult trial shows good response rates but no significant long-term outcome benefit from prone positioning in patients with ARDS. Routine scheduled assessments of readiness for weaning and extubation may be more important than specific weaning modes and weaning criteria for children. A recent meta-analysis suggests that prophylactic dexamethasone use may decrease postextubation stridor and possibly reduce the need for reintubation in selected patients. Outcome data in children requiring mechanical support is encouraging, especially for high-risk groups such as bone marrow transplant (BMT) recipients, and may guide ethically challenging decision-making for these patients.

SUMMARY

Mechanical ventilation strategies aiming for optimal alveolar recruitment with the judicious use of positive end-expiratory pressure (PEEP) and low tidal volumes will remain the mainstay for managing respiratory failure in children. Dexamethasone may prevent postextubation stridor. Prone positioning, surfactant therapy, HFOV, and inhaled NO are used sporadically and need to be evaluated for their effect on mortality and duration of ventilation.