Abstract
BACKGROUND: Acute kidney injury (AKI) is associated with high morbidity and mortality. The continuum of kidney damage after an AKI episode is poorly explored in the paediatric population. METHODS: We performed a retrospective cohort study on 2346 children with AKI from a tertiary care hospital in Romania over a 9-year period. The main objective was to evaluate the impact of AKI duration on mortality and the risk of new-onset chronic kidney disease (CKD). RESULTS: Out of 2346 AKI patients, transient AKI was present in 655 patients (27.9%), persistent AKI in 1009 children (43%) and acute kidney disease in 682 patients (29.1%). In contrast to transient AKI, children who developed acute kidney disease were younger, with a higher degree of anaemia, lower number of platelets, higher procalcitonin, higher LDH, higher GGT, higher urea and higher serum creatinine levels. The pre-renal cause of AKI was the leading cause regardless of AKI duration. As kidney injury progressed over time, there was an increasing incidence of the intrinsic causes of AKI (11.1% in transient AKI, 13.2% in persistent AKI and 22.6% in acute kidney disease). Acute kidney disease patients had the highest mortality rate (16.42%), followed by transient AKI (14.66%) and persistent AKI (9.81%). Overall mortality increased in the presence of renal microvascular alterations, acute tubular necrosis, lower haemoglobin, serum proteins and platelets, and higher procalcitonin levels. CONCLUSIONS: The continuum of AKI expressed as acute kidney disease resulted in an increased risk of new-onset CKD. CKD was influenced by the intrinsic cause of AKI and not by AKI severity.