ORIGINAL ARTICLE Outcome of pediatric acute kidney injury: a multicenter prospective cohort study Jameela A. Kari 1 & Khalid A. Alhasan 2 & Mohamed A. Shalaby 1 & Norah Khathlan 3 & Osama Y. Safdar 1 & Suleman A. Al Rezgan 4 & Sherif El Desoky 1 & Amr S. Albanna 5 Received: 7 June 2017 /Revised: 26 July 2017 /Accepted: 10 August 2017 # IPNA 2017 Abstract Background Acute kidney injury (AKI) is a common problem encountered in critically ill children with an increasing inci- dence and evolving epidemiology. AKI carries a serious mor- bidity and mortality in patients requiring admission to a pedi- atric intensive care unit (PICU). Methods We undertook a prospective cohort study of PICU admissions at three tertiary care hospitals in the Kingdom of Saudi Arabia over 2 years. The Kidney Disease Improving Global Outcomes (KDIGO) definition was used to diagnose AKI. Results A total of 1367 pediatrics PICU admissions were in- cluded in the study. AKI affected 511 children (37.4%), with 243 children (17.8%) classified as stage I (mild), 168 patients (12.3%) stage II (moderate), and 100 children (7.3%) were classified as stage III (severe). After adjustment for age, sex, and underlying diagnosis, in-hospital mortality was six times more likely among patients with AKI as compared to patients with normal renal function (adjusted OR: 6.5, 95% CI: 4.2– 10). AKI was also a risk factor for hypertension (adjusted OR: 4.1, 95% CI: 2.8–5.9) and prolonged stay in the PICU and hospital, as it increased the average number of admission days by 10 (95% CI: 8.6–11) days in the PICU and 12 (95% CI: 10–14) days in the hospital. Conclusions One-third of PICU admissions were complicated with AKI. AKI was associated with increased hospital mor- tality and the length of stay in both PICU and hospital. Keywords Acute kidney injury . Intensive care unit . KDIGO . Outcome . Children Introduction Acute kidney injury (AKI) is common in critically ill children with an increasing incidence and evolving epidemiology [1]. It represents a continuum of morbidity that can vary from subclinical injury, with minimal serum creatinine changes, to severe oligo-anuric kidney failure requiring renal replacement therapy (RRT) in up to 4–6% [2]. The use of the term acute renal failure (ARF) is preferably restricted to AKI requiring RRT Fig. 1 [3]. Serum creatinine is widely used and still considered as the gold standard test for diagnosis of AKI. However, creatinine is well known as being an insensitive biomarker since it does not significantly increase until about half of the kidney function is lost [ 4]. Novel AKI biomarkers such as kidney injury molecule-1 (KIM-1), plasma neutrophil gelatinase-associated lipocalin (pNGAL), urinary NGAL (uNGAL), interleukin-18 (IL-18) and serum cystatin C (s-Cys-C) have been proposed and inves- tigated as markers of early detection of kidney damage [4]. To overcome these diagnostic limitations, new diagnostic criteria are used. The AKI Network (AKIN) proposed diagnostic criteria * Jameela A. Kari jkari@kau.edu.sa; jkari@doctors.org.uk 1 Pediatric Nephrology Center of Excellence, Department of Pediatrics, King Abdulaziz University, PO Box 80215, Jeddah 21589, Kingdom of Saudi Arabia 2 Pediatrics Department, College of Medicine, King Khalid University Hospital, King Saud University, Riyadh, Kingdom of Saudi Arabia 3 Intensive Care Unit, Department of Pediatrics, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia 4 King Fahad Armed Forces Hospital, Jeddah, Kingdom of Saudi Arabia 5 King Abdullah International Medical Research Center, King Saud Bin Abdulaziz University for Health Sciences, Jeddah, Kingdom of Saudi Arabia Pediatr Nephrol DOI 10.1007/s00467-017-3786-1