Acute kidney injury

Acute kidney injury (AKI) is commonly associated with sepsis, cardiovascular collapse, congestive heart failure, major surgery, nephrotoxins (such as antibiotics, intravenous contrast, or other drugs), or urinary outflow obstruction.

May present with flank pain, hematuria, hypertension or hypotension, edema, lethargy, uremia, or decreased urine output; however, often asymptomatic and only diagnosed by laboratory tests.

An acute increase in serum creatinine is essential for diagnosis. Fluid overload, hyperkalemia, hyperphosphatemia, metabolic acidosis, and elevated urea nitrogen are common.

The mainstay of treatment is supportive care, with management of the underlying illness; correction of acid/base, electrolyte, and volume complications; removal or minimization of nephrotoxins; and relief of any associated obstruction being key.

Renal replacement therapy with dialysis may be required and is usually well tolerated.

Failure to treat may be associated with clinical deterioration and death. Outcome is dependent upon the severity of the kidney injury and the underlying disease.

AKI, previously known as acute renal failure (ARF), is an acute decline in renal function, leading to a rise in serum creatinine and/or a fall in urine output.[1]Kidney Disease: Improving Global Outcomes (KDIGO) Acute Kidney Injury Work Group. KDIGO clinical practice guideline for acute kidney injury. Kidney Int Suppl. 2012 Mar;2(1):1-138. https://kdigo.org/wp-content/uploads/2016/10/KDIGO-2012-AKI-Guideline-English.pdf The change in terminology emphasizes that kidney injury presents as a disease spectrum from mild renal impairment to severe renal failure.[1]Kidney Disease: Improving Global Outcomes (KDIGO) Acute Kidney Injury Work Group. KDIGO clinical practice guideline for acute kidney injury. Kidney Int Suppl. 2012 Mar;2(1):1-138. https://kdigo.org/wp-content/uploads/2016/10/KDIGO-2012-AKI-Guideline-English.pdf [2]Palevsky PM, Liu KD, Brophy PD, et al. KDOQI US commentary on the 2012 KDIGO clinical practice guideline for acute kidney injury. Am J Kidney Dis. 2013 May;61(5):649-72. https://www.ajkd.org/article/S0272-6386(13)00471-X/fulltext http://www.ncbi.nlm.nih.gov/pubmed/23499048?tool=bestpractice.com [3]National Institute for Health and Care Excellence. Acute kidney injury: prevention, detection and management. Oct 2024 [internet publication]. https://www.nice.org.uk/guidance/ng148 A standardized definition is important to facilitate clinical care and research.[4]Thomas ME, Blaine C, Dawnay A, et al. The definition of acute kidney injury and its use in practice. Kidney Int. 2015 Jan;87(1):62-73. http://www.ncbi.nlm.nih.gov/pubmed/25317932?tool=bestpractice.com AKI may be due to various insults such as impaired renal perfusion, exposure to nephrotoxins, outflow obstruction, or intrinsic renal disease. The resulting effects include impaired clearance and regulation of metabolic homeostasis, altered acid/base and electrolyte regulation, and impaired volume regulation.