Early continuous renal replacement therapy for acute kidney injury in a very low birth weight infant: a case report and literature review.

INTRODUCTION

Very low birth weight (VLBW) preterm infants are particularly vulnerable to acute kidney injury (AKI) because of immature renal function and limited physiological reserve. However, the use of continuous renal replacement therapy (CRRT) in this population remains technically demanding and clinically challenging. We report a case of successful early CRRT implementation for severe AKI secondary to perinatal asphyxia in a VLBW infant, together with a review of the relevant literature.

CASE PRESENTATION: A female infant born at 31+6 weeks of gestation with a birth weight of 1,470 g was admitted to the neonatal intensive care unit (NICU) following severe perinatal asphyxia. Shortly after admission, she developed persistent oliguria, progressive metabolic acidosis, azotemia, and fluid overload, consistent with stage 3 AKI. Despite comprehensive supportive management, including mechanical ventilation, vasoactive support, and correction of electrolyte and acid-base disturbances, renal function and hemodynamic status continued to deteriorate. CRRT in continuous venovenous hemodiafiltration (CVVHDF) mode was initiated approximately 20 h after birth using a low initial blood flow rate and a gradual individualized ultrafiltration strategy. After 37 h of treatment, urine output increased from 0.11 to 3.9 mL/(kg·h), serum creatinine decreased from 118.20 to 55.20 μmol/L, and blood urea nitrogen decreased from 12.27 to 5.26 mmol/L, accompanied by marked improvement in metabolic status and circulatory stability. The infant was subsequently weaned from CRRT and invasive mechanical ventilation and was discharged in stable condition.

CONCLUSION

In VLBW infants with AKI, early and graduated CRRT intervention may contribute to maintaining hemodynamic stability and facilitating organ function recovery. Meticulous peri-CRRT management is essential to ensure treatment safety.