Introduction Acute kidney injury (AKI), characterised by acute decline in renal function is associated with significant morbidity and mortality in children. This study reviewed the aetiology, treatment modalities and outcome of children with AKI managed in the paediatric nephrology unit at the University hospital of Wales, Cardiff.

Method Retrospective analysis of referral practises, aetiology, and management of 38 children with AKI over the last 5 years. Outcomes noted as complete recovery, residual renal injury, renal replacement therapy (RRT) dependency or death. Children primarily treated in intensive care were excluded.

Result 34% of the total 38 patients were under 5 years of age. Haemolytic uraemic syndrome (HUS) was the commonest cause of AKI 18/38 (47.3%) with E coli 0157 accounting for most (15/18). Significant number of these cases required dialysis (10/15). 3 children had atypical HUS, one secondary to pneumococcal infection and other 2 with no known cause despite thorough workup. Obstructive renal failure (5 cases) was second most common and renal function improved following relief of obstruction. Overall, supportive management sufficed in 23/38 cases and 15 received renal replacement therapy (RRT). Most children on dialysis were oliguric (14/15). Peritoneal dialysis was the commonest mode of RRT used. 2 children needed plasma exchange. Outcome was equally favourable irrespective of mode of RRT. At 3 months there were no deaths; 29 (76%) had completely recovered, 5 children had estimated glomerular filtration rate (eGFR) between 40- 60 ml/min/1.73m2, 2 had mild to moderate proteinuria and one was hypertensive. One child who remained dialysis dependant with moderate hypertension and proteinuria needed renal transplantation 2 years later. On most recent follow up eGFR had normalised in 2 and improved, between 70–75 ml/min/1.73m2 in other 3 children. Proteinuria had resolved in one but persisted in the other.

Discussion Prognosis following AKI was excellent in children not needing intensive care probably because of lack of multiorgan dysfunction. HUS was the commonest cause of AKI. AKIs with oliguria are more likely to require dialysis and should be referred early to the nephrology team. All cases should have long-term follow up to ensure renal recovery and detect delayed complications.