Acute Kidney Injury

Abstract

1. David T. Selewski, MD* 2. Jordan M. Symons, MD† 1. *Department of Pediatrics and Communicable Diseases, Division of Nephrology, C.S. Mott Children’s Hospital, University of Michigan, Ann Arbor, MI. 2. †Department of Pediatrics, Division of Nephrology, University of Washington School of Medicine, Seattle, WA. * Abbreviations: ACE: : angiotensin-converting enzyme AKI: : acute kidney injury AKIN: : Acute Kidney Injury Network ANCA: : antineutrophil cytoplasmic antibody ATN: : acute tubular necrosis ECG: : electrocardiogram FEurea: : fractional excretion of urea FENa: : fractional excretion of sodium KDIGO: : Kidney Disease: Improving Global Outcomes NSAID: : nonsteroidal anti-inflammatory drug RIFLE: : Risk, Injury, Failure, Loss, and End-stage The term acute kidney injury has replaced acute renal failure and represents a spectrum of clinically meaningful kidney damage. After completing this article, readers should be able to: 1. Recognize and define the spectrum of acute kidney injury (AKI). 2. Understand the diagnostic approach and be able to differentiate the main causes of AKI. 3. Understand the complications of AKI and the treatment of a child with AKI. Acute kidney injury (AKI), formerly called acute renal failure, is characterized by multiple abnormalities, including increases in serum creatinine and blood urea nitrogen, electrolyte abnormalities, acidosis, and difficulties with fluid management. We have come to realize that what was previously thought to be relatively minor damage to the kidney can have significant short-term effects on morbidity and mortality and potential long-term implications for the development of chronic kidney disease. Thus, the term acute kidney injury has replaced acute renal failure , suggesting the spectrum of kidney damage that can occur. ### Definition AKI is classically defined as an acute decrease in glomerular filtration rate, which results in an increase in serum creatinine. It is important to recognize the limitations of creatinine as a marker of AKI because an increase in creatinine can be delayed by as much as 48 hours after damage to the kidney has occurred. Despite this limitation, change in creatinine remains the gold standard for the diagnosis of AKI. An evolution in the definition of AKI to better understand, characterize, and study the disease spectrum, has occurred, which has sought to capture the clinical importance of even small variations in kidney function. In addition, previous definitions used in the literature were widely disparate; this …