Practical information outlining tips to aid feed tolerance in children with chronic kidney disease.
Poor appetite, uremia and gastrointestinal (GI) challenges such as reflux, emesis and delayed gastric emptying, can all contribute to why calorie intake can be limited and thus why children with CKD may struggle with weight gain 1, 2. Addressing these obstacles one at a time will help optimize feeding tolerance for this group of patients.
These may be mostly non-modifiable factors and can be due to the decline in kidney function. However, managing biochemical values may potentially aid a reduction in symptoms. Children who are acidotic often experience a poor appetite and poor growth.
The KDOQI pediatric nutrition guideline recommend CO2 levels to remain ≥22 mEq/L1. North American data indicates that only one third of children with CO2 levels ≤18 are treated with alkali therapy3.
Using a feed which is low in chloride and potassium, such as Renastart, may help to improve acidosis3, 5. Reducing protein intake to reduce BUN may be another intervention to reduce uremia1.
Many children with CKD, and especially those on dialysis, may need tube feeding support6. Providing any needed calories and protein via a tube feed and adjusting the tube feeding timing to individual tolerance can help to mitigate the effects of a poor oral intake 7, 8.
Children with CKD and on dialysis may lose up to a third of their feeds through emesis7. Over 70% have severe gastroesophageal reflux9. Delayed gastric emptying is another challenge8.
Medication is certainly an option to treat these conditions1, however, nutritional intervention can also help. Providing as much breastmilk as possible, if it is available, is an ideal choice1. Breastmilk is well tolerated, high in whey content, and has a micronutrient profile suited to management of CKD5. Whey proteins are known to aid with digestion and gastric emptying and so choosing a predominately whey based formula when breastmilk is not available is another option9.
Using a whey-based renal specific feed, such as Renastart, in conjunction with a standard infant formula or standard paediatric enetral feed, may be an option if hyperkalaemia or hyperphosphatamia are an issue. Timing of feeding may be important as well8.
Although it is ideal to offer daytime bolus feeds to pattern physiologic oral feeding, continuous feeding, especially nocturnal continuous feeding, may help ease volume concerns that trigger GI issues. However, monitoring timing and length of continuous feeding is important. Some children have greater emesis toward the end of overnight continuous feeding because of volume accumulation. Children receiving peritoneal dialysis may have dialysate dwells that, especially toward the end of overnight dialysis passes, may increase volume pressure5. Offering oral intake ad lib, especially before a tube feed is given, may help a child to self-regulate and learn to gauge volume tolerance independently7.
Use of a gastrostomy tube (GT) is preferred for chronic tube feeding needs (>6 weeks), which is typically expected as CKD progresses10. Nasogastric tubes (NG) may irritate the back of the throat and nasal cavity, which can increases emesis and cause oral aversions11.
Lastly, although using a more concentrated base formula can help reduce volume, which can aid with GI issues, sometimes the density of the feed can increase emesis and nausea. So, carefully evaluating the individual child for benefit versus problems with concentrated feeding is important. Individual or combination macronutrient modulars can also help meet increased calorie needs when volume is limited5.
Children receiving dialysis may have limited or no urine output, and consequently, maximizing caloric intake of feeds is necessary to ensure growth. At the same time, children with CKD, even those on dialysis, may have renal tubular defects which causes problems with concentrating urine1. These children have high volume loss and may need supplemental fluid and sodium.
For the child who needs volume reduction, increasing the caloric content of the feeds is necessary, either by increasing the base formula density or by adding macronutrient modulars. Concentrating base formula density must be done with a careful eye on micronutrient increases, limiting those that can be detrimental in excess for children with CKD, such as potassium or vitamin A1, 5. However, there is merit to limiting the number of products necessary for formula mixing, to ease complication for the caregiver and potentially reduce errors12. The density of the formula may need to be adjusted based on feeding tolerance, and in some situations, an increase in intensity of dialysis may be necessary to allow for more fluid volume13.
The child who needs additional fluid may still have difficulty meeting caloric needs with a large volume of formula, as additional formula may cause GI problems. Thus, some concentration of fortification of feeds may be necessary to meet caloric needs, with additional free water given to meet fluid needs. These may be given as flushes after feeding, in between feeds or orally, to satisfy thirst, based on the tolerance and desires of the child. It is important that free water and formula intake be appropriately spaced to prevent unsafe electrolyte declines from a large amount of free water given at one time1, 5.
Some children may have unique GI issues in addition to having CKD. Formula intolerances or cows milk protein allergy may be present in children with CKD in the same percentages that they are present in the general population. In this case, the formula must be chosen based on the GI intolerance to prevent serious issues like allergy related side effects, blood in the stool, extreme diarrhea or vomiting. The formula chosen to aid with the GI concerns can be modified with other formula, medication or modulars to make it more appropriate for renal biochemical issues5.
In short, whatever the problem a child may be having with feeding tolerance, trialing formula timing and administration alterations may solve the problem, changing the base formula may be the solution, or the use of medications may be enough to resolve these tolerance issues – it just takes the careful eye of a trained clinician and evaluating the individual child and their needs or their family’s needs to determine the best course4.
1) KDOQI Workgroup. (2009) KDOQI Clinical Practice Guideline for Nutrition in Children with CKD: 2008 update. Executive summary. Am J Kidney Dis 53(3 Suppl 2):S11- 104
2) United States Renal Data System USRDS annual data report: epidemiology of kidney disease in the United States. National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda MD, 2017. (2017) Available online at: https://www.usrds.org/2017/view/v2_07.aspx on (Accessed March 15, 2019).
3) Rodig N, McDermott K, Schneider M, Hotchkiss H, Yadin O, Seikaly M, et al. Growth in children with chronic kidney disease: a report from the chronic kidney disease in children study. Pediatr Nephrol. (2014) 29:1987–95
4) Chua A, Warady B. Care of the pediatric patient on chronic dialysis. Adv Chronic Kidney Dis. (2017) 24:388–97.
5) Nelms C. L. (2018) Optimizing Enteral Nutrition for Growth in Pediatric Chronic Kidney Disease (CKD). Front Pediatr. 6, 214. doi:10.3389/fped.2018.00214
6) Coleman J, Watson A, Rance C, Moore E. Gastrostomy buttons for nutritional support on chronic dialysis. Nephrol Dial Transplant. (1998) 13:2041–6.
7) Rees L, Brandt M. Tube feeding in children with chronic kidney disease: technical and practical issues. Pediatr Nephrol. (2010) 25:699–704.
8) Foster B, McCauley L, Mak R. Nutrition in infants and very young children with chronic kidney disease. Pediatr Nephrol. (2012) 27:1427–39.
9) Ruley EJ, Bock G, Kerzner B, Abbott A, Majd M, Chatoor I. Feeding disorders and gastroesophageal reflux in infants with chronic renal failure. Pediatr Nephrol. (1989) 3:424–9.
10) Monczka J. Enteral nutrition support: determining the best way to feed. In: Corkins MR, editor. editor. The American Society for Parenteral and Enteral Nutrition Pediatric Nutrition Support Core Curriculum. 2nd Edn. Silver Spring, MD: The American Society for Parenteral and Enteral Nutrition; (2015) p. 256–82.
11) Warady BA, Kriley M, Belden B, Hellerstein S, Alon U. Nutritional and behavioral aspects of nasogastric tube feeding in infants, receiving chronic peritoneal dialysis. Adv Perit Dial. (1990) 6:265–8.
12) Evans S, Daly A, Ashmore C. Nutritional content of modular feeds: how accurate is feed production? Arch Dis Child. (2013) 98:184–8.
13) Fischbach M, Fothergill H, Seuge L, Zaloszyc A. Dialysis strategies to improve growth in children with chronic kidney disease. J Ren Nutr. (2011) 21:43–6.