CSR Pediatric Renal Nutrition 1 — Questions and Answers

Question 1: In infants with CKD or ESRD, ensuring adequate caloric intake is critical for growth. What is the MOST common reason infants with CKD fail to thrive despite adequate prescribed calorie intake?

Too much protein causing osmotic diarrhea
Uremic anorexia, vomiting, and oral aversion leading to inadequate actual oral intake — requiring tube feeding supplementation (Correct answer)
Excessive physical activity burning prescribed calories
Genetic growth hormone resistance unrelated to nutrition

Correct answer: Uremic anorexia, vomiting, and oral aversion leading to inadequate actual oral intake — requiring tube feeding supplementation

Uremic anorexia, recurrent vomiting, and oral aversion (from chronic illness/NG tube experience) frequently prevent infants with CKD from voluntarily consuming adequate calories. Gastrostomy tube (G-tube) feeding is often necessary to achieve prescribed energy targets for growth.

Infants with CKD/ESRD face multiple barriers to adequate oral intake: (1) Uremic anorexia (uremic toxin accumulation suppresses appetite centers); (2) Vomiting from uremia, GERD (common in CKD infants), and medications; (3) Oral feeding aversion from repeated oral/nasopharyngeal procedures; (4) Fatigue and reduced suckling strength; (5) Fluid restriction limiting volume that can be offered orally. Consequences of inadequate intake: failure to thrive (linear growth < -2 SD below mean for age), permanent cognitive and neurodevelopmental impairment. Intervention: nasogastric (NG) tube or gastrostomy (G-tube) feeding with concentrated formula allows target calorie delivery. G-tube reduces caregiver burden and allows overnight feeds. KDOQI pediatric guidelines recommend early enteral support when oral intake consistently < 80% of target for 1 month.

Question 2: Which parameter is the BEST clinical indicator of adequate nutritional support for linear growth in a child with CKD?

Serum albumin level maintained > 4.0 g/dL
Height velocity (change in height over time) plotted on standard growth charts compared to age/sex norms (Correct answer)
Body mass index above the 50th percentile
Serum blood urea nitrogen < 30 mg/dL

Correct answer: Height velocity (change in height over time) plotted on standard growth charts compared to age/sex norms

Height velocity (cm/year) plotted on growth charts is the primary indicator of adequate linear growth and nutritional support in pediatric CKD. Adequate growth requires sufficient energy, protein, calcium, phosphorus, vitamin D, and growth hormone signaling.

Linear growth assessment in pediatric CKD: (1) Height-for-age Z-score (HAZ): target > -2 SD; (2) Height velocity: expected velocity by age (infants: 25 cm/year in year 1, 12 cm/year in year 2; school-age: 5–6 cm/year; puberty: 8–12 cm/year peak); (3) Compare height velocity to age/sex reference curves. Growth failure (HAZ < -1.88, or 5th percentile) affects 30–65% of children with CKD Stage 3–5D. Causes: CKD-related metabolic acidosis (suppresses GH-IGF1 axis), uremia, CKD-MBD (bone disease), nutritional inadequacy, and growth hormone resistance. Treatment: correction of acidosis (bicarbonate supplementation), nutritional optimization, phosphate/calcium management, recombinant human growth hormone (rhGH) for growth failure when other factors optimized. Regular dietitian assessment with growth chart tracking every visit.

Question 3: For a 3-year-old child with CKD Stage 5 on peritoneal dialysis, caloric requirements per kg body weight are HIGHER or LOWER compared to an adult on PD?

Lower — children need fewer calories per kg than adults
Higher — children require more calories per kg (80–120 kcal/kg/day) than adults to support growth and development (Correct answer)
The same — pediatric and adult requirements per kg are identical
Only protein requirements differ; energy requirements per kg are the same

Correct answer: Higher — children require more calories per kg (80–120 kcal/kg/day) than adults to support growth and development

Young children have significantly higher energy needs per kg body weight than adults due to the demands of rapid growth, high metabolic rate, and organ development. A 3-year-old requires approximately 80–120 kcal/kg/day, compared to 30–35 kcal/kg/day for adults.

Pediatric energy recommendations (DRI-based) decrease with age: infants 0–6 months: 100–110 kcal/kg/day; 6–12 months: 80–100 kcal/kg/day; 1–3 years: 80–100 kcal/kg/day; 4–8 years: 70–90 kcal/kg/day; adolescents: 45–60 kcal/kg/day. KDOQI pediatric CKD/dialysis: recommend achieving at least 100% of DRI for energy to support normal growth. In practice, children with CKD/PD often need 100–120% DRI due to uremic anorexia, GI symptoms, and metabolic stress. PD glucose absorption (calculated per kg) also contributes energy: for children on CAPD with higher surface area-to-weight ratio, dialysate glucose absorption per kg can be substantial and must be accounted for in energy calculations. Energy supplementation via G-tube feedings with concentrated pediatric formulas (e.g., Pediasure 1.5, modified renal formulas) is frequently necessary.

Question 4: In a child with CKD Stage 3–4, which vitamin/mineral is MOST critical to monitor and supplement to prevent renal osteodystrophy and support bone growth?

Vitamin C in megadoses
Active vitamin D (calcitriol or alfacalcidol) combined with calcium supplementation to normalize PTH and support bone mineralization during growth (Correct answer)
Vitamin K2 in isolation
Thiamine (vitamin B1) in megadoses

Correct answer: Active vitamin D (calcitriol or alfacalcidol) combined with calcium supplementation to normalize PTH and support bone mineralization during growth

In CKD Stage 3–4, impaired 1α-hydroxylase activity reduces calcitriol (active vitamin D) production, contributing to hypocalcemia, hyperphosphatemia, secondary hyperparathyroidism, and CKD-MBD — all of which severely impair linear bone growth in children. Active vitamin D supplementation and calcium management are critical.

CKD-mineral and bone disorder in children: CKD-MBD is particularly harmful in pediatric patients because bone modeling and remodeling must support longitudinal growth. Secondary hyperparathyroidism (SHPT) causes renal osteodystrophy (osteitis fibrosa cystica), bone pain, fractures, and growth retardation. KDIGO pediatric CKD-MBD guidelines: (1) Serum 25-OH vitamin D: target > 30 ng/mL with ergocalciferol or cholecalciferol supplementation; (2) Active vitamin D (calcitriol 0.01–0.05 mcg/kg/day, or alfacalcidol) for PTH suppression when serum 25-OH-D is sufficient but PTH remains elevated; (3) Calcium supplements if dietary calcium inadequate (DRI for children 500–1300 mg/day by age); (4) Phosphate restriction and binders for hyperphosphatemia. PTH targets in pediatric CKD-MBD: Stage 3: 35–70 pg/mL; Stage 4: 70–110 pg/mL; Stage 5D: 200–300 pg/mL (allowing some elevation for adequate bone turnover).

Question 5: The MOST important reason to use nasogastric or gastrostomy tube feeding in a pediatric patient with ESRD rather than relying solely on oral feeding is:

Oral feeding is contraindicated in all ESRD children
Tube feeding ensures predictable, adequate intake to meet the high caloric and nutritional requirements for normal growth and neurodevelopment when oral intake is chronically insufficient due to uremic anorexia and vomiting (Correct answer)
Tube feeding prevents the need for dialysis
Tube feeding is preferred because oral feeding causes CKD progression

Correct answer: Tube feeding ensures predictable, adequate intake to meet the high caloric and nutritional requirements for normal growth and neurodevelopment when oral intake is chronically insufficient due to uremic anorexia and vomiting

The primary indication for tube feeding in pediatric ESRD is ensuring sufficient caloric intake for growth and neurodevelopment when uremic anorexia, vomiting, and oral aversion prevent adequate voluntary intake. Critical growth windows (especially 0–2 years and puberty) cannot be missed.

Tube feeding indications in pediatric CKD/ESRD (KDOQI criteria): Oral intake consistently < 80% of needs for >1 month; active growth failure (height velocity < 25th percentile for bone age); BMI < 5th percentile despite dietary counseling; failure to achieve target intake with oral supplementation. Gastrostomy tube (PEG, surgically placed) advantages over NG tube: (1) More comfortable and permanent for long-term use; (2) Caregiver ease (no tube insertion/displacement); (3) Allows overnight continuous feeds (maximizing intake without daytime interference); (4) Reduces oral aversion (daily NG tube insertion worsens aversion). Important: tube feeding must run simultaneously with oral feeding attempts (combined approach) to maintain oral motor skills and minimize further aversion. Transition back to oral feeding as tolerated with growth improvement. Neurodevelopmental benefits: adequate caloric intake in first 2 years of life is irreversible for cognitive development.

Question 6: A 10-year-old child on hemodialysis has consistent pre-dialysis potassium of 6.8 mEq/L. After reviewing their 3-day food record, which high-potassium food item is MOST commonly over-consumed in the pediatric dialysis population?

Baked potatoes and sweet potatoes
Fruit juices, sports drinks, and carbonated beverages (especially those with added potassium) (Correct answer)
Egg whites and lean chicken
White rice and white bread

Correct answer: Fruit juices, sports drinks, and carbonated beverages (especially those with added potassium)

Children and adolescents on dialysis frequently consume fruit juices, sports drinks (e.g., Gatorade contains high potassium), and flavored sodas — all high in potassium — and often report these as 'beverages' rather than 'food,' making them easy to overlook in dietary assessment.

Pediatric-specific high-potassium sources often consumed in excess: (1) Fruit juices: orange, prune, tomato juice (200–700 mg K+/8 oz) — commonly given to children; (2) Sports drinks (Gatorade, Powerade): 37–70 mg K+/8 oz, often consumed in large quantities by active children; (3) Smoothies: banana/avocado-based blended drinks; (4) Flavored milk (chocolate milk: high potassium from milk + cocoa); (5) Fast food french fries: large portions consumed by adolescents. Pediatric dietary assessment challenge: children/teens often underreport beverages on food records; sports drinks are perceived as 'healthy' and not reported as problematic foods. Dietitian strategies: specifically ask about all beverages (juice, sports drinks, smoothies, flavored milks); review school lunch menus; involve parents/caregivers in dietary counseling. Identify low-potassium beverage alternatives: diluted lemonade, filtered water, Crystal Light (check label for K+).

CSR Pediatric Renal Nutrition 1

In infants with CKD or ESRD, ensuring adequate caloric intake is critical for growth.
What is the MOST common reason infants with CKD fail to thrive despite adequate prescribed calorie intake?