Use of Renastart™ in CKD stage 5 | Case Study
DESCRIPTION
A case study on the use of Renastart in a child with CKD stage 5.
The patient is a 21 month old male who was diagnosed with CKD stage 5 due to Fanconi syndrome (a kidney tubule disorder) at birth. He has a history of faltering growth.
The patient was admitted at the age of 21 months to start haemodialysis (HD) due to CKD stage 5 and ophthalmological deterioration. He was previously on conservative management for chronic kidney disease (CKD) at another centre. A gastrostomy feeding tube was already in place to manage persistent vomiting.
Relevant medications
| Medication | Reason for Use |
| Alpha-Leo 3 drops, 2/day D-cure 5 drops, 1/day |
Vitamin D supplements |
| Ferricure 15 drops, 2/day | Iron supplement - to treat anaemia |
| NaCl 750mg | Sodium chloride supplement |
| Pyridoxine 110mg | B Vitamin supplement |
| Omeprazole 2.5ml, 2/day | Anti reflux medication |
| Aranesp 20μg, 1/day every 6 weeks (IV) | Iron injection to treat anaemia |
| Age | 21 months |
| Weight (kg) | 11.4 |
| Height (cm) | 82 |
| Percentile on the growth chart | Weight: 10th centile Height: 25th centile |
Biochemistry before starting HD
| Potassium (mmol/l) | 4.8 Ref Range* (3.6-4.8) |
| Phosphate (mmol/dl) | 0.93 Ref Range* (3.1-7.4) |
| Urea (mg/dl) | ⬆ 50 Ref Range* (3.1-7.4) |
| Creatinine (mg/dl) | ⬆ 1.32 Ref Range* (3.1-7.4) |
| GFR (ml/min) | 22 |
* Ref: Hospital reference range.
Nutritional requirements
Energy: 78-82 kcal/kg/day1 = 890-935 kcal/day
Protein: 1.4 g/kg/day1 = 16 g/day
No other dietary restrictions
Dietary intake
146 g semi-elemental infant feed + 70 g carbohydrate powder (maltodextrin) + 1250 ml water, continuous feed by gastrostomy at 66 ml/hour.
Providing
| Energy (kcal) | 946 83 kcal/kg |
| Protein (g) | 16.94 1.5 g/kg |
| Potassium (mg) | 830 72 mg/kg |
| Phosphorus (mg) | 496 43.5 mg/kg |
| Sodium (mg) | 255 22.4 mg/kg |
This feed was low in sodium (Na) therefore a 750 mg NaCl supplement was added to provide 295 mg additional sodium. The feed combined with the supplement provided 550 mg (48.2 mg/kg) sodium.
An extensively hydrolysed protein, lactose free formula was chosen by clinicians in the previous medical centre to manage extreme vomiting (not for the management of cow’s milk allergy).
The feed described above was continued after HD commenced, despite frequent vomiting, as the patients serum potassium levels remained within the reference range. After two months on dialysis, the catheter blocked and a replacement was required. HD was not possible. Without regular dialysis the patient was at risk of hyperkalemia.
Dietary management
When it was not possible for HD, a low potassium feed was required.
Therefore the feed was changed to Renastart™. Due to the patient’s history of vomiting and poor tolerance, the concentration of Renastart was reduced from 20% (standard dilution) to 12%.
Biochemistry and growth were monitored carefully on this feed plan due to the reduction in dietary potassium and phosphate intake.
| Age | 2 years |
| Weight (kg) | 11.41 |
| Percentile on the growth chart | Weight: 10th centile |
Biochemistry before starting Renastart
| Potassium (mmol/l) | 4.9 Ref Range* (3.6-4.8) |
| Phosphate (mmol/dl) | 1.73 Ref Range* (1-2) |
| Urea (mg/dl) | 18 Ref Range* (12-48) |
| Creatinine (mg/dl) | ⬆ 1.38 Ref Range* (0.31-0.47) |
* Ref: Hospital reference range
Nutritional requirements
Energy: 78-82 kcal/kg/day1 = 890-935 kcal/day
Protein: 1.4 g/kg/day1 = 16 g/day
Poor weight gain over the previous 2 months was noted. This may have been related to ongoing challenges with frequent vomiting and therefore nutritional losses. An increased energy feed was provided.
Feeding Plan
Feed change to Renastart: 146 g Renastart + 70 g carbohydrate powder (maltodextrin) made up to 1250 ml water to provide 12% concentration. Delivered as continuous feed by gastrostomy at 66 ml/hour.
Providing
| Energy (kcal) | 987 87kcal/kg |
| Protein (g) | 10.95 0.96g/kg |
| Potassium (mg) | 171 15mg/kg |
| Phosphorus (mg) | 134 11.7mg/kg |
| Sodium (mg) | 357 31mg/kg |
Renastart was used for 4 days. The patient’s potassium levels remained within the reference range. It was important to ensure regular monitoring of the patient’s electrolyte levels due to the low intake of potassium from the feed.
Biochemistry while on Renastart
| Potassium (mmol/l) | 4.0 Ref Range* (3.6-4.8) |
| Phosphate (mmol/dl) | 1.36 Ref Range* (1-2) |
| Urea (mg/dl) | 34 Ref Range* (12-48) |
| Creatinine (mg/dl) | ⬆ 2.22 Ref Range* (0.31-0.47) |
* Ref: Hospital reference range
Intake of protein was below estimated requirements, however this amount was given safely for a short period without HD to keep potassium levels within a safe range and to manage symptoms of persistent vomiting.
Four days later, the catheter was replaced and HD recommenced. The patient returned to his previous feed of 146 g semi-elemental infant feed + 70 g carbohydrate powder (maltodextrin) + 1250 ml water, delivered continuously.
On review 1 month later, his potassium level remained within the reference range and his weight increased to 11.7 kg (10th centile on growth chart).
The medical team agreed to continue this feed and monitor his tolerance and electrolyte levels regularly.
The patient went on to require a combination feed which included Renastart to manage raised serum potassium levels while awaiting a transplant
- Renastart can be used to enable a low potassium intake to be achieved when serum potassium levels are raised. This can help to maintain patient safety during times when HD is not possible (for example if a catheter is blocked).
- It is important to monitor electrolyte levels and nutritional status regularly and adapt the feeding plan according to results.
1. Royle J. Chapter 12: Kidney Disease. In: Shaw V, editor. Clinical Paediatric Dietetics. 4: John Wiley & Sons Ltd.; 2015. p. 242-81.
