The use of Renastart™ as a modular feed as part of the dietary management of paediatric Chronic Kidney Disease (CKD) | Case Study
DESCRIPTION
Case study describing how Renastart can be used as part of a modular feed in a child with CKD.
The patient is a 6 year old female with CKD stage 5.
Initially presented at age 4 with vomiting, diarrhoea and anaemia. Echogenic kidneys on ultrasound, diagnosis of nephronophthisis, CKD stage 4. Progressed to CKD stage 5 at 5 years of age.
Relevant history
Anthropometry: History of growth faltering between -4SD and -5SD on centile chart1 for weight. Height fell from 0.4th centile to -4SD from age 4 to 6 years. Now on -3SD for both weight and height.
Biochemistry while on haemodialysis
| Urea | 28 mmol/L ⬆ |
| Potassium | 6.0 mmol/L ⬆ |
| Phosphate | 1.93 mmol/L ⬆ |
| Creatinine | 515 umol/L ⬆ |
Feeding history: Unsafe swallow. Initially fed via a nasogastric tube (NGT) and then had a gastrostomy inserted. Currently receiving an amino acid formula due to chronic vomiting. Phosphate binders given during gastrostomy feed.
| Medication | Reason for use |
| Calcium acetate | Phosphate binder |
| 1-alfacalcidol | Vitamin D supplement |
| Cholecalciferol | Vitamin D supplement |
| Lactulose | To manage constipation |
| Erythromycin | Prokinetic |
| Lansoprazole | Anti reflux medication – to manage retching |
Anthropometry
- Weight 12.5 kg (<0.4th centile)1
- Height: 103 cm (<0.4th centile)1
Overall aim
To improve nutritional status and increase weight and height towards the 0.4th centile whilst managing serum urea, potassium and phosphate levels.
Nutritional requirements/assessment
Minimal oral intake. Majority of nutritional requirements fed via enteral tube. Requirements based on a height age of 4 years.
Estimated Average Requirement (EAR)2
81 kcal/kg + 20-50% for catch up growth: 97 kcal/kg-120 kcal/kg = 1200 kcal-1500 kcal
Protein Reference Nutrient Intake (RNI)2
20 g protein per day (+0.1 g/kg for HD losses3 ) = 21 g or 1.68 g/kg protein
Dietetic intervention
Moved to jejunal feeding due to poor growth and ongoing vomiting. A low potassium feed was trialled for a short period of approximately 7 days as a means of reducing dietary potassium intake due to hyperkalaemia. Bloods were checked regularly throughout this period and the feed was tolerated well.
A modular feed was then devised consisting of a low potassium feed, a high energy paediatric feed and a glucose polymer as shown in the table below. This feed was devised to ensure nutritional requirements were met whilst still continuing to manage serum potassium and phosphate levels. This feed provided 1.81 kcal/ml and 3.1 g protein / 100 ml.
| Feed | Quantity | % |
|---|---|---|
| 2.4 kcal/ml high energy paediatric feed | 288 mls | 36 |
| Low potassium feed (Renastart) | 80 g | 10 |
| Glucose polymer powder | 86 g | 12 |
| Water | up to 800 mls | 42 |
| Total | 800 mls |
The patient managed 500 ml - 600 ml of the feed per day, providing 80 kcal/kg and 1.4 g/kg protein. The phosphate binders were discontinued due to serum phosphate levels being managed via dietary means i.e. the use of a low electrolyte feed.
Monitoring
The patient was reviewed regularly and the amount and proportions of the low potassium feed, the high energy paediatric feed and the glucose polymer were adjusted based on serum potassium, phosphate and urea levels. This ensured additional calories were provided without exceeding protein requirements and whilst managing serum potassium and phosphate levels.
Monitoring/review
- Once stable, the patient attended hospital monthly for regular monitoring of urea and electrolyte levels, height, weight, nutritional intake, medications and clinical status.
Outcome measures
- Weight was maintained along her growth trajectory during end stage kidney disease.
- Serum urea, potassium and phosphate levels were managed within acceptable limits when Renastart was used as part of a modular feed.
- Support was provided to the patient and parents by ensuring the dietetic plan was as simple as possible, to aid overall quality of life.
Main findings
Renastart can be used in conjunction with a 2.4 kcal/ml high energy paediatric feed to ensure protein intake is not exceeded, and serum potassium and phosphate levels are managed.
Limitations / challenges
The child struggled with gastro-intestinal tolerance to the feed and the desired volume (of approximately 800 mls) could never be achieved. Although oral intake was minimal, the types of food consumed varied (for example some high in phosphate vs nil phosphate) which potentially affected her blood results.
Identified learning
When a child is in end stage kidney disease, it is difficult to achieve the desired weight gain with catch up growth. It can be more realistic to aim to maintain their nutritional status, manage symptoms and optimise biochemistry. This child started to gain weight and grow successfully following a renal transplant at 7 years of age.
Devising a modular feed including a low potassium feed can help ensure energy and protein requirements are met whilst managing serum potassium and phosphate levels in those children with CKD. Growth maintenance is achievable in patients with end stage renal disease but achieving catch up weight gain and growth can be more challenging.
- Have realistic goals for weight and height in children with CKD stage 5.
- Regular reviews both in the hospital setting and via telephone are essential to ensure optimal monitoring and support for the family.
- Regular review of oral intake and medications is important as a child’s intake and adherence with both can vary.
- RCPCH. 2012. UK-WHO growth charts - 2-18 years. [online]. Available from: https://www.rcpch.ac.uk/resources/uk-who-growth-charts-2-18-years
- Great Ormond Street Hospital for Children NHS Trust. 2018 Nutritional Requirements for Children in Health and Disease. Great Ormond Street.
- National Kidney Foundation. KDOQI Clinical Practice Guideline for Nutrition in Children with CKD: 2008 Update. American Journal of Kidney Diseases. 2009; 53(S2): S1-S124.
