Optimizing Enteral Nutrition for Growth in Pediatric Chronic Kidney Disease (CKD)

Growth after pediatric kidney transplantation: a 25-year study in a pediatric kidney transplant center

OBJECTIVES

Growth failure is one of the major complications of pediatric chronic kidney disease. Even after a kidney transplant (KT), up to 50 % of patients fail to achieve the expected final height. This study aimed to assess longitudinal growth after KT and identify factors influencing it.

METHODS

A retrospective observational study was performed. We reviewed the clinical records of all patients who underwent KT for 25 years in a single center (n=149) and performed telephone interviews. Height-for-age and body mass index (BMI)-for-age were examined at KT, 3 months, 6 months, 1 year, and 5 years post-transplant and at the transition to adult care. We evaluated target height, disease duration before KT, need and type of dialysis, recombinant human growth hormone pretransplant use, nutritional support, glomerular filtration rate (GFR), and cumulative corticosteroid dose.

RESULTS

At transplant, the average height z-score was -1.38, and height z-scores showed catch-up growth at 6 months (z-score -1.26, p=0.006), 1 year (z-score -1.15, p<0.001), 5 years after KT (z-score -1.08, p<0.001), and on transition to adult care (z-score -1.22, p=0.012). Regarding BMI z-scores, a significant increase was also detected at all time points (p<0.001). After KT, GFR was significantly associated with height z-score (p=0.006) and BMI z-score (p=0.006). The height in transition to adult care was -1.28 SD compared to the target height.

CONCLUSIONS

Despite the encouraging results regarding catch-up growth after KT in this cohort, results remain far from optimum, with a lower-than-expected height at the time of transition.

Chronic kidney disease in children: an update

Chronic kidney disease (CKD) is a major healthcare issue worldwide. However, the prevalence of pediatric CKD has never been systematically assessed and consistent information is lacking in this population. The current definition of CKD is based on glomerular filtration rate (GFR) and the extent of albuminuria. Given the physiological age-related modification of GFR in the first years of life, the definition of CKD is challenging per se in the pediatric population, resulting in high risk of underdiagnosis in this population, treatment delays and untailored clinical management. The advent and spreading of massive-parallel sequencing technology has prompted a profound revision of the epidemiology and the causes of CKD in children, supporting the hypothesis that CKD is much more frequent than currently reported in children and adolescents. This acquired knowledge will eventually converge in the identification of the molecular pathways and cellular response to damage, with new specific therapeutic targets to control disease progression and clinical features of children with CKD. In this review, we will focus on recent innovations in the field of pediatric CKD and in particular those where advances in knowledge have become available in the last years, with the aim of providing a new perspective on CKD in children and adolescents.

Pediatric formulas: Categories, composition, and considerations

Formulas, liquid nutrition, may be consumed orally or via a feeding tube to provide partial or complete nutrition that a given individual could not obtain using natural food stuffs in their native form. A wide range of commercially available formulas exist, which may be used as sole-source nutrition or in conjunction with other foods. Physicians and dietitians must understand the nature of and indications for specific formulas to treat diseases, provide complete nutrition to patients, and avoid harm. Products vary in macronutrient and micronutrient content and calorie concentration among many other factors. They are formulated specifically for patients of specific ages, correlating to nutritional needs and medical diagnoses. Additionally, formula availability, insurance coverage, mode of consumption, physiologic tolerance, and caregiver preference influence formula selection. Caregivers may also make their own pediatric formulas. We review commercial and homemade pediatric formulas.

Scoping review of the dietary intake of children with chronic kidney disease

BACKGROUND

Adequate nutrition is integral to optimal health outcomes for children with chronic kidney disease. However, no studies to date have summarised the existing knowledge base on the dietary intake of this patient group.

OBJECTIVE

Analyse and summarise evidence regarding the dietary intake of children with chronic kidney disease and identify areas that require further research or clarification.

METHODS

A scoping review of English language articles using four bibliographic databases and a predefined search term strategy. Weighted mean intake for each nutrient was calculated.

RESULTS

Eighteen studies were identified (1407 children and 118 healthy controls). Data on socioeconomic status, underreporting of intake and binder use was sparse. Most studies collected dietary information using food records or 24-h recalls. Nutrient data was missing for many subgroups especially transplant and dialysis patients. Protein intake was excessive in all groups where data was reported and varied from 125.7 ± 33% of the recommended dietary allowance in the severe disease group to 391.3 ± 383% in the group with mild kidney disease. Fibre, calcium, iron and vitamin C intake was inadequate for all groups. For children undertaking dialysis, none met the recommended dietary allowance for vitamins C, B1, B2, B3, B5 and B6. Sodium intake was excessive in all groups (> 220% of the recommended dietary allowance). Limited data suggests diet quality is poor, particularly fruit and vegetable intake.

CONCLUSIONS

This review has identified important subgroups of children with kidney disease where nutrient intake is suboptimal or not well described. Future studies should be conducted to describe intake in these groups. A higher-resolution version of the graphical abstract is available as Supplementary information.

Fluid management in hospitalized pediatric patients

The proper use of intravenous fluids has likely been responsible for saving more lives than any other group of substances. Proper use includes prescribing an appropriate electrolyte and carbohydrate solution, at a calculated rate or volume, for the right child, at the right time. Forming intravenous fluid plans for hospitalized children requires an understanding of water and electrolyte physiology in healthy children and how different pathology deviates from the norm. This review highlights fluid management in several disease types, including liver disease, diabetic ketoacidosis, syndrome of inappropriate antidiuretic hormone, diabetes insipidus, kidney disease, and intestinal failure as well as in those with nonphysiologic fluid losses. For each disease, the review discusses specific considerations, evaluations, and management strategies to consider when customizing intravenous fluid plans. Ultimately, all hospitalized children should receive an individualized fluid plan with recurrent evaluations and fluid modifications to provide optimal care.

Managing the Nutritional Requirements of the Pediatric End-Stage Kidney Disease Graduate

The pediatric patient with end-stage kidney disease who transitions to the adult dialysis unit or nephrology center requires a unique nutritional focus. Clinicians in the adult center may be faced with complex issues that have often been part of the patient's journey since early childhood. The causes of kidney disease in children are often quite different than those which affect the adult population and may require different nutritional priorities. Abnormal growth including severe short stature, underweight, overweight or obesity, and poor musculature may affect the long-term health and psychosocial well-being of these patients. Nutritional assessment of these patients should include a focus on past growth and anthropometric data, dietary information, including appetite, quality of diet, and assessment of biochemical data through a pediatric lens. This review discusses the unique factors that must be considered when transitioning pediatric patients and notes major recommendations from a compilation of pediatric guideline statements.

Monitoring dialysis adequacy: history and current practice

Dialysis adequacy for pediatric patients has largely followed the trends in adult dialysis by judging the success or adequacy of peritoneal or hemodialysis with urea kinetic modeling. While this provides a starting point to establish a dose of dialysis, it is clear that urea is only part of the picture. Many clinical parameters and interventions now have been identified that are just as impactful on mortality and morbidly as urea clearance. As such, our concept of adequacy is evolving to include non-urea parameters and assessing the impact that following an "adequate therapy" has on patient lives. As we move to a new era, we consider the impact these therapies have on patients and how it affects the quality of their lives; we must take these factors into consideration to achieve a therapy that is not just adequate, but livable.

Differences in Dietary Intake and Vitamin and Mineral Status of Infants and Children on Dialysis Receiving Feeds or Eating Normal Food

OBJECTIVES

Knowledge of the vitamin and mineral intake and status of children on dialysis is scarce. Guidelines suggest supplementation of water-soluble vitamins, but the need for supplementation of minerals is less clear. We evaluated vitamin and mineral intake and status of children on chronic dialysis in our center.

METHODS

We reviewed patient records of all 33 children aged 0-16 years who were treated with chronic dialysis at a University Hospital between December 2014 and August 2019. Dietary intake was estimated from feed prescriptions and 3-day food records. Vitamin and mineral determinations were performed as part of routine care.

RESULTS

Food records or adherence to dietary prescription of feeds were available for 29 children. Dietary intake of most nutrients was sufficient in children on feeds, but children not on feeds had low intakes of vitamins D, B1, B2, and B6 as well as zinc, iron, and calcium from their diet. Insufficient intake was corrected with supplementation. We discovered some children with blood concentrations below the reference range for vitamins D (3.1%) and C (15.4%) and copper (16.7%) and selenium (3.1%). In contrast, various proportions of children with blood concentrations above the reference range were detected for all nutrients apart from vitamin D.

CONCLUSIONS

In our study, children receiving sufficient amounts of renal-specific feeds to meet at least 100% of age-specific requirements do not appear to need multivitamin-mineral supplementation, apart from vitamin D and calcium; in addition, children on PD usually need a sodium supplement and, on rare occasions with low intake from feeds, a phosphate supplement is needed. This study further revealed that other children at our center are more prone to deficient intakes of several vitamins and minerals, requiring supplementation based on dietetic review and, in some instances, laboratory measurements.

The prevalence and outcome of children with failure to thrive after pediatric kidney transplantation

BACKGROUND

Prior to transplantation, effects of advanced CKD contribute to malnutrition and impaired growth. After transplant, children are expected to thrive, however, in a subset of transplant recipients this does not occur. Factors associated with post-transplant FTT are poorly understood.

OBJECTIVE

A retrospective cohort study was conducted to determine factors associated with FTT and association of FTT with infections and hospitalizations.

METHODS

Records of 119 children transplanted between 2005 and 2016 were reviewed. FTT was defined by ≥2 of the following post-transplant criteria: (a) low BMI or deceleration in BMI z-score, (b) poor growth velocity, and (c) chronic hypoalbuminemia at 1 or 3 years post-transplant. Association of FTT with deceased donor transplant, de novo DSA, intolerance to MMF, anemia, vitamin D deficiency, and CIC was investigated by logistic regression. Poisson regression was used to identify outcomes associated with FTT.

RESULTS

Low pre-transplant BMI and post-transplant CIC dependence were independently associated with FTT after transplant. Odds of FTT at 1 year post-transplant decreased by 0.5 for each 1 unit increase in pre-transplant BMI z-score. Requirement for CIC conferred 3.8 and 7.8 higher odds of FTT at 1 and 3 years. Patients with FTT had 2.7 and 2.6 times infections and hospitalizations during the first year, and 4.2 and 4.3 times infections and hospitalizations over 3 years post-transplant.

CONCLUSIONS

Children with low BMI prior to transplant and those requiring CIC after transplant are at increased risk for post-transplant FTT. FTT is associated with adverse outcomes, evidenced by increased infections and hospitalizations.

Risk Assessment of Severe Congenital Anomalies of the Kidney and Urinary Tract (CAKUT): A Birth Cohort

Recent advances in the early diagnosis of fetal CAKUT with an increase in fetal surgical interventions have led to a growing number of neonatal survivors born with severe renal dysfunction. This, in turn, has required the development of multi-disciplinary treatment paradigms in the individualized management of these infants with advanced stage kidney disease from birth. Early multi-modal management includes neonatal surgical interventions directed toward establishing adequate urine flow, respiratory support with the assessment of pulmonary hypoplasia, and establishing metabolic control to avoid the need for dialysis intervention. The development of specialized imaging to assess for residual renal mass with non-invasive 3-dimensional techniques are rapidly evolving. The use of non-radioactive imaging offers improved safety and allows for early prognostic-based planning including anticipatory guidance for progression to end stage renal disease (ESRD). The trajectory of kidney function during the neonatal period as determined by peak and nadir serum creatinine (SCr) and cystatin C (CysC) during the first months of life provides a guide toward individualized prospective management. This is a single center experience based on a birth cohort of 42 subjects followed prospectively from birth for an average of 6.1 ± 2.8 years at the University of Miami/Holtz Children's Hospital during the past decade. There was an 8:1 male: female ratio. The birth cohort was divided into 3 subgroups according to CKD Stages at the current age: CKD 1-2 (Group 1) (eGFR ≥ 60 ml/min/1.73 m²) (N = 15), CKD stage 3-5 (Group 2) (eGFR ≤ 59 ml/min/1.73 m²) (N = 12), and ESRD-Dialysis and/or Transplantation (Group 3) (N = 15). A neonatal CysC >3.0 mg/L predicted progression to ESRD while a nadir SCr >0.6 mg/dL predicted progression to CKD 3-5 with the highest specificity and sensitivity by ROC-AUC analysis (P < 0.0001). Medical management was directed toward nutritional support with novel formula designs, early introduction of growth hormone and strict control of mineral bone disorder. One of the central aspects of the management was to avoid dialysis for as long as feasible with a primary goal toward pre-emptive transplantation.