Enid E. Martinez

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.

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 subjects 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.

Gastric Dysmotility in Critically Ill Children: Pathophysiology, Diagnosis, and Management.

Objective: We aimed to review gastric dysmotility in critically ill children: 1) its pathophysiology, with a focus on critical care diseases and therapies that affect gastric motility, 2) diagnostic methodologies, and 3) current and future potential therapies. Data Sources: Eligible studies were identified from PubMed and MEDLINE. Study Selection: Literature search included the following key terms: “gastric emptying,” “gastric motility/dysmotility,” “gastrointestinal motility/dysmotility,” “nutrition intolerance,” and “gastric residual volume.” Data Extraction Studies since 1995 were extracted and reviewed for inclusion by the authors related to the physiology, pathophysiology, diagnostic methodologies, and available therapies for gastric emptying. Data Synthesis: Delayed gastric emptying, a common presentation of gastric dysmotility, is present in up to 50% of critically ill children. It is associated with the potential for aspiration, ventilator-associated pneumonia, and inadequate delivery of enteral nutrition and may affect the efficacy of enteral medications, all of which may be result in poor patient outcomes. Gastric motility is affected by critical illness and its associated therapies. Currently available diagnostic tools to identify gastric emptying at the bedside have not been systematically studied and applied in this cohort. Gastric residual volume measurement, used as an indirect marker of delayed gastric emptying in PICUs around the world, may be inaccurate. Conclusions: Gastric dysmotility is common in critically ill children and impacts patient safety and outcomes. However, it is poorly understood, inadequately defined, and current therapies are limited and based on scant evidence. Understanding gastric motility and developing accurate bedside measures and novel therapies for gastric emptying are highly desirable and need to be further investigated.

The science and art of pediatric critical care nutrition.

Purpose of reviewNutritional status and nutrient delivery during critical illness impact clinical outcomes. We have reviewed recent studies that may guide best practices regarding nutrition therapy in critically ill children. Recent findingsMalnutrition is prevalent in the pediatric ICU population, and is associated with worse outcomes. Nutrition support teams, dedicated dietitians, and educational programs facilitate surveillance for existing malnutrition and nutrition risk, but specific tools for the pediatric ICU population are lacking. Estimation of macronutrient requirements is often inaccurate; novel strategies to accurately determine energy expenditure are being explored. Indirect calorimetry remains the reference method for measuring energy expenditure. Enteral nutrition is the preferred route for nutrition in patients with a functioning gut. Early enteral nutrition and delivery of adequate macronutrients, particularly protein, have been associated with improved clinical outcomes. Delivery of enteral nutrition is often interrupted because of fasting around procedures and perceived intolerance. Objective measures for detection and management of intolerance to nutrient intake are required. In low-risk patients who are able to tolerate enteral nutrition, supplemental parenteral nutrition may be delayed during the first week of critical illness. SummarySystematic research and consensus-based practices are expected to promote optimal nutritional practices in critically ill children with the potential to improve clinical outcomes.

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.

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.

Challenges to Nutrition Therapy in the Pediatric Critically Ill Obese Patient

BACKGROUND Obesity has been associated with poor clinical outcomes in critically ill children. The optimal approach to nutrition therapy in this vulnerable cohort is unclear. METHODS We report the nutrition management of 2 obese patients admitted to a pediatric intensive care unit (PICU). We focus on their nutrition assessment, energy requirements, and macronutrient delivery. RESULTS Case 1 describes a 19-year-old male, body mass index (BMI) 52.4 kg/m(2), who was admitted after emergent orthopedic surgery. Case 2 describes a 13-year-old male, BMI 31.5 kg/m(2), who was admitted with respiratory distress. Average PICU length of stay was 2 months. Nutrition assessments, including weight and height, were obtained early and regularly. Skinfold measurements were challenging. Estimated energy expenditure by predictive equations was significantly higher compared with measured resting energy expenditure (MREE) by indirect calorimetry in both cases. The Mifflin St-Jeor equation (in case 1) overestimated MREE by 681 kcal/d; the Schofield equation (in case 2) overestimated MREE by 662 kcal/d. Both patients had barriers to enteral nutrition and prolonged periods of time when they received no enteral nutrition, requiring parenteral nutrition for 28% and 75% of their PICU stay, respectively. Average daily protein delivered was 0.8 g/kg and 1 g/kg, below adult recommended protein intake for obese patients and pediatric recommendations for age. CONCLUSIONS These cases were notable for (1) challenges to anthropometric assessments, (2) inaccurate estimates of energy requirements, (3) suboptimal enteral nutrition delivery, (4) need for supplemental parenteral nutrition, and (5) suboptimal protein intake. Research is needed to determine the best approach to nutrition therapy in this cohort.

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.

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). Spearmans 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.

Comprehensive nutritional and metabolic assessment in patients with spinal muscular atrophy: Opportunity for an individualized approach

Optimal nutrition support is recommended for patients with spinal muscular atrophy (SMA). In a prospective study, we performed comprehensive nutritional assessments with the aim to guide best nutritional strategies for patients with SMA types II and III. We recorded a) anthropometry; b) macro- and micronutrient intakes; c) measured resting energy expenditure by indirect calorimetry; and d) body composition including dual X-ray absorptiometry. We enrolled a cohort of 21 patients aged 3 to 36 years of which 13 were female; 19 had SMA type II and 2 had SMA type III. The body mass index z-score ranged from -3 to 2.4. Forty-five percent of the cohort was either underfed or overfed, based on the difference between actual energy intake and measured resting energy expenditure. Vitamin D, E, K, folate and calcium intakes were low in a majority of the cohort. Forty-five percent of the cohort was either hypometabolic or hypermetabolic. Fat mass index (kg/m2) was significantly higher and lean body mass index (kg/m2) was significantly lower in the study cohort compared to population normalized values. Bone mineral density was low in 13 of 17 patients. In summary, we have described the prevalence of malnutrition, suboptimal feeding and alterations in body composition in children with SMA. A comprehensive nutritional assessment could guide individualized nutrition therapy in this vulnerable population.