Growth in neonates with congenital kidney failure requiring continuous kidney replacement therapy

With advanced technology, survival of neonates with congenital kidney failure (CKF) requiring continuous kidney replacement therapy (CKRT) has improved. Nutrition is essential but difficult to attain as CKRT removes proteins and micronutrients, and many patients have multiple co-morbidities. Scant data exist to guide clinicians on appropriate energy requirements for growth.

We performed a retrospective study of neonates with CKF admitted to Children's of Alabama between 2016 and 2022 who required KRT within 10 days. We evaluated risk factors and growth in the 18/24 (75%) infants who survived to 90 days. Our primary and secondary outcomes were length z-score ≥  - 2 vs. <  - 2 at 90 days and weight z-score ≥  - 2 vs. <  - 2 at 90 days, respectively. Demographics, comorbidities, CKRT Dose Eras (1-body surface area (2000/1.73/m²/hr) vs. 2-weight-based era (24 ml/kg/hr)), and Nutrition Era 1 vs. 2 were evaluated.

At 90 days, 7/18 (38.9%) had length z-score ≥  - 2 while 10/18 (55.6%) had a weight z-score ≥  - 2. Factors for weight z-score ≥  - 2 include time to PD transition and CKRT Dose Era 2. Factors for length z-score ≥  - 2 included Era with higher calorie and protein goal targets (both p < 0.01).

Malnutrition in neonates with CKF on CKRT is high. More studies are needed to better understand optimal strategies to ensure adequate growth. Until then, we recommend 24 ml/kg/hr clearance dose and prescribing at least 130 kcal/kg/day and 4 g/kg/day amino acids to target higher actual intake to start for these patients.