Background
Acute kidney injury (AKI) is a common problem in critically ill children and is associated with high rate of mortality.  The definition and staging of AKI has been recently standardized using the RIFLE classification and the KDIGO classifications. Most cases of AKI represent acute tubular necrosis that is secondary to hypovolemia, sepsis or the use of nephrotoxic agents.
 
Aim of the study
To investigate the frequency, risk factors and outcome in critically ill children and to compare the pRIFLE and KDIGO classifications.
 
Patients and methods
 100 critically ill children admitted to the pediatric intensive care unit (PICU) were screened for AKI using both pRIFLE and KDIGO classifications. All included children were subjected to full history taking, full clinical examination, assessment of disease severity at admission, daily monitoring of urine output serum creatinine and calculation of estimated GFR and inotrope score.

Results
Thirty –eight percent of our patients had developed AKI during their course of stay. There was no significant difference between the two scoring systems at admission at day 3and at day 7 post admission. Infant age group, duration of stay > 7 days, the use of vasoactive drugs, nephrotoxic drugs and mechanical ventilation were risk factors for the development of AKI. Mortality was significantly higher in patients with AKI (58% versus 13%, p= .008). Conclusion
 Lower age, higher IS score and mechanical ventilation were independent risk factors for AKI. AKI was associated with higher mortality and was associated with significantly longer ICU stay.