The reported incidences of AKI vary, and are confounded by differences in diagnosis, definition criteria, or hospital discharge coding.[6]Centers for Disease Control and Prevention (CDC). Hospitalization discharge diagnoses for kidney disease: United States, 1980-2005. MMWR Morb Mortal Wkly Rep. 2008 Mar 28;57(12):309-12.
http://www.ncbi.nlm.nih.gov/pubmed/18368005?tool=bestpractice.com
[7]Ali T, Khan I, Simpson W, et al. Incidence and outcomes in acute kidney injury: a comprehensive population-based study. J Am Soc Nephrol. 2007 Apr;18(4):1292-8.
https://jasn.asnjournals.org/content/18/4/1292.long
http://www.ncbi.nlm.nih.gov/pubmed/17314324?tool=bestpractice.com
The rate of hospitalizations for AKI in US Medicare patients increased by approximately 35% between 2010 and 2019.[8]National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases. 2022 United States Renal Data System (USRDS) annual data report: epidemiology of kidney disease in the United States. 2022 [internet publication].
https://usrds-adr.niddk.nih.gov/2022
Patients with diabetes were hospitalized with AKI at a greater than 2-fold higher rate compared with those without diabetes, and patients with chronic kidney disease (CKD) and diabetes were hospitalized with AKI at a more than 7.5-fold higher rate compared to patients with neither pre-existing condition.[8]National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases. 2022 United States Renal Data System (USRDS) annual data report: epidemiology of kidney disease in the United States. 2022 [internet publication].
https://usrds-adr.niddk.nih.gov/2022
Overall incidence of AKI among hospitalized patients ranges from 13% to 22%.[3]National Institute for Health and Care Excellence. Acute kidney injury: prevention, detection and management. Dec 2019 [internet publication].
https://www.nice.org.uk/guidance/ng148
[9]Wang HE, Muntner P, Chertow GM, et al. Acute kidney injury and mortality in hospitalized patients. Am J Nephrol. 2012;35(4):349-55.
https://www.karger.com/Article/FullText/337487
http://www.ncbi.nlm.nih.gov/pubmed/22473149?tool=bestpractice.com
In the intensive care unit (ICU), the incidence of AKI is higher.[10]Case J, Khan S, Khalid R, et al. Epidemiology of acute kidney injury in the intensive care unit. Crit Care Res Pract. 2013;2013:479730.
https://www.hindawi.com/journals/ccrp/2013/479730
http://www.ncbi.nlm.nih.gov/pubmed/23573420?tool=bestpractice.com
Prediction scores have been developed for outcomes of AKI, but have had variable success in terms of reproducibility or utility.[11]Ohnuma T, Uchino S, Toki N, et al. External validation for acute kidney injury severity scores: a multicenter retrospective study in 14 Japanese ICUs. Am J Nephrol. 2015;42(1):57-64.
http://www.ncbi.nlm.nih.gov/pubmed/26337793?tool=bestpractice.com
[12]Poukkanen M, Vaara ST, Reinikainen M, et al. Predicting one-year mortality of critically ill patients with early acute kidney injury: data from the prospective multicenter FINNAKI study. Crit Care. 2015 Mar 27;19:125
https://ccforum.biomedcentral.com/articles/10.1186/s13054-015-0848-2
http://www.ncbi.nlm.nih.gov/pubmed/25887685?tool=bestpractice.com
Acute tubular necrosis (ATN) accounts for 45% of cases of AKI. ATN is caused by sepsis in approximately 20% of ICU patients. Prerenal azotemia, obstruction, glomerulonephritis, vasculitis, acute interstitial nephritis, acute on chronic kidney disease, and atheroembolic injury account for most of the remainder.[13]Mehta R, Pascual MT, Soroko S, et al. Spectrum of acute renal failure in the intensive care unit: the PICARD experience. Kidney Int. 2004 Oct;66(4):1613-21.
http://www.ncbi.nlm.nih.gov/pubmed/15458458?tool=bestpractice.com
[14]Liaño F, Pascual J. Epidemiology of acute renal failure: a prospective, multicenter, community-based study. Madrid Acute Renal Failure Study Group. Kidney Int. 1996 Sep;50(3):811-8.
http://www.ncbi.nlm.nih.gov/pubmed/8872955?tool=bestpractice.com
The incidence of contrast nephropathy varies, and is reported to be the third most common cause of AKI in hospitalized patients. One large systematic review and meta-analysis reported a 9% incidence of contrast-induced nephropathy in patients undergoing angiography for any reason, including percutaneous intervention for coronary artery disease, with 0.5% of patients requiring dialysis.[15]Wu MY, Lo WC, Wu YC, et al. The incidence of contrast-induced nephropathy and the need of dialysis in patients receiving angiography: a systematic review and meta-analysis. Front Med (Lausanne). 2022 Apr 27;9:862534.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9091353
http://www.ncbi.nlm.nih.gov/pubmed/35573008?tool=bestpractice.com
Up to 7% of patients hospitalized with AKI require renal replacement therapy.[16]Liangos O, Wald R, O'Bell JW, et al. Epidemiology and outcomes of acute renal failure in hospitalized patients: a national survey. Clin J Am Soc Nephrol. 2006 Jan;1(1):43-51.
https://cjasn.asnjournals.org/content/1/1/43.long
http://www.ncbi.nlm.nih.gov/pubmed/17699189?tool=bestpractice.com
In the ICU, the mortality rate exceeds 50% in patients with multiorgan failure who require dialysis.[13]Mehta R, Pascual MT, Soroko S, et al. Spectrum of acute renal failure in the intensive care unit: the PICARD experience. Kidney Int. 2004 Oct;66(4):1613-21.
http://www.ncbi.nlm.nih.gov/pubmed/15458458?tool=bestpractice.com
[14]Liaño F, Pascual J. Epidemiology of acute renal failure: a prospective, multicenter, community-based study. Madrid Acute Renal Failure Study Group. Kidney Int. 1996 Sep;50(3):811-8.
http://www.ncbi.nlm.nih.gov/pubmed/8872955?tool=bestpractice.com
[16]Liangos O, Wald R, O'Bell JW, et al. Epidemiology and outcomes of acute renal failure in hospitalized patients: a national survey. Clin J Am Soc Nephrol. 2006 Jan;1(1):43-51.
https://cjasn.asnjournals.org/content/1/1/43.long
http://www.ncbi.nlm.nih.gov/pubmed/17699189?tool=bestpractice.com
Minor rises in creatinine (≥0.3 mg/dL) are associated with an increased risk of hospital mortality, increased risk of chronic kidney disease, and higher odds of progressing to end-stage renal failure.