Risk Factors of Acute Kidney Injury in Critically Ill Children.

OBJECTIVES: Acute kidney injury may be promoted by critical illness, preexisting medical conditions, and treatments received both before and during ICU admission. We aimed to estimate the frequency of acute kidney injury during ICU treatment and to determine factors, occurring both before and during the ICU stay, associated with the development of acute kidney injury.

DESIGN: Cohort study of critically ill children.

SETTING: University-affiliated PICU.

PATIENTS: Eligible patients were admitted to the ICU between January 2006 and June 2009. We excluded those admitted with known primary renal failure, chronic renal failure or postrenal transplant, conditions with known renal complications, or metabolic conditions treated with dialysis. Patients were also excluded if they had a short ICU stay (< 6 hr) and those who had no creatinine or urine output measurements during their ICU stay.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Of the 3,865 pediatric patients who met the inclusion criteria, 915 (23.7%) developed acute kidney injury, as classified by the Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease criteria, during their ICU stay. Patients at high risk for development of acute kidney injury included those urgently admitted to the ICU (adjusted odds ratio, 1.88), those who developed respiratory dysfunction during their ICU care (adjusted odds ratio, 2.90), and those who treated with extracorporeal membrane oxygenation (adjusted odds ratio, 2.72). The single greatest risk factor for acute kidney injury was the administration of nephrotoxic medications during ICU admission (adjusted odds ratio, 3.37).

CONCLUSIONS: This study, the largest evaluating the incidence of RIFLE-defined acute kidney injury in critically ill children, found that one-quarter of patients admitted to the ICU developed acute kidney injury. We identified a number of potentially modifiable risk factors, the largest of which was the administration of nephrotoxic medication. The results of this study may be used to inform targeted interventions to reduce acute kidney injury and improve the outcomes of critically ill children.