Background: The objective of this study was to determine the incidence of acute kidney injury (AKI) and its relation with mortality among hospitalized patients. Methods: Analysis of hospital discharge and laboratory data from an urban academic medical center over a 1-year period. We included hospitalized adult patients receiving two or more serum creatinine (sCr) measurements. We excluded prisoners, psychiatry, labor and delivery, and transferred patients, ‘bedded outpatients’ as well as individuals with a history of kidney transplant or chronic dialysis. We defined AKI as (a) an increase in sCr of ≥0.3 mg/dl; (b) an increase in sCr to ≥150% of baseline, or (c) the initiation of dialysis in a patient with no known history of prior dialysis. We identified factors associated with AKI as well as the relationships between AKI and in-hospital mortality. Results: Among the 19,249 hospitalizations included in the analysis, the incidence of AKI was 22.7%. Older persons, Blacks, and patients with reduced baseline kidney function were more likely to develop AKI (all p < 0.001). Among AKI cases, the most common primary admitting diagnosis groups were circulatory diseases (25.4%) and infection (16.4%). After adjustment for age, sex, race, admitting sCr concentration, and the severity of illness index, AKI was independently associated with in-hospital mortality (adjusted odds ratio 4.43, 95% confidence interval 3.68–5.35). Conclusions: AKI occurred in over 1 of 5 hospitalizations and was associated with a more than fourfold increased likelihood of death. These observations highlight the importance of AKI recognition as well as the association of AKI with mortality in hospitalized patients.

Keywords:
Acute kidney injury, Chronic kidney disease, Mortality, Health services
1.
Chertow GM, Burdick E, Honour M, Bonventre JV, Bates DW: Acute kidney injury, mortality, length of stay, and costs in hospitalized patients. J Am Soc Nephrol 2005;16:3365–3370.
2.
Uchino S, Bellomo R, Goldsmith D, Bates S, Ronco C: An assessment of the RIFLE criteria for acute renal failure in hospitalized patients. Crit Care Med 2006;34:1913–1917.
3.
Nash K, Hafeez A, Hou S: Hospital-acquired renal insufficiency. Am J Kidney Dis 2002;39:930–936.
4.
Liangos O, Wald R, O’Bell JW, Price L, Pereira BJ, Jaber BL: Epidemiology and outcomes of acute renal failure in hospitalized patients: a national survey. Clin J Am Soc Nephrol 2006;1:43–51.
5.
Waikar SS, Curhan GC, Ayanian JZ, Chertow GM: Race and mortality after acute renal failure. J Am Soc Nephrol 2007;18:2740–2748.
6.
Bellomo R, Ronco C, Kellum JA, Mehta RL, Palevsky P: Acute renal failure – definition, outcome measures, animal models, fluid therapy and information technology needs: the Second International Consensus Conference of the Acute Dialysis Quality Initiative (ADQI) Group. Crit Care 2004;8:R204–R212.
7.
Mehta RL, Kellum JA, Shah SV, Molitoris BA, Ronco C, Warnock DG, Levin A: Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury. Crit Care 2007;11:R31.
8.
Ricci Z, Cruz D, Ronco C: The RIFLE criteria and mortality in acute kidney injury: a systematic review. Kidney Int 2008;73:538–546.
9.
Bagshaw SM, George C, Bellomo R: Early acute kidney injury and sepsis: a multicentre evaluation. Crit Care 2008;12:R47.
10.
Liborio AB, Abreu KL, Silva GB Jr, Lima RS, Barreto AG, Barbosa OA, Daher EF: Predicting hospital mortality in critically ill cancer patients according to acute kidney injury severity. Oncology 2011;80:160–166.
11.
Lopes JA, Fernandes P, Jorge S, Resina C, Santos C, Pereira A, Neves J, Antunes F, Gomes da Costa A: Long-term risk of mortality after acute kidney injury in patients with sepsis: a contemporary analysis. BMC Nephrol 2010;11:9.
12.
Uchino S, Kellum JA, Bellomo R, Doig GS, Morimatsu H, Morgera S, Schetz M, Tan I, Bouman C, Macedo E, Gibney N, Tolwani A, Ronco C: Acute renal failure in critically ill patients: a multinational, multicenter study. JAMA 2005;294:813–818.
13.
Levey AS, Stevens LA, Schmid CH, Zhang YL, Castro AF 3rd, Feldman HI, Kusek JW, Eggers P, Van Lente F, Greene T, Coresh J, CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration: A new equation to estimate glomerular filtration rate. Ann Intern Med 2009;150:604–612.
14.
Mortality Risk Adjustment Methodology for University Health System’s Clinical Data Base, available at http://www.ahrq.gov/qual/mortality/Meurer.htm (accessed September 16, 2011).
15.
Angus DC, Linde-Zwirble WT, Lidicker J, Clermont G, Carcillo J, Pinsky MR: Epidemiology of severe sepsis in the United States: analysis of incidence, outcome, and associated costs of care. Crit Care Med 2001;29:1303–1310.
16.
Wang HE, Shapiro NI, Angus DC, Yealy DM: National estimates of severe sepsis in United States emergency departments. Crit Care Med 2007;35:1928–1936.
17.
Lafrance JP, Miller DR: Defining acute kidney injury in database studies: the effects of varying the baseline kidney function assessment period and considering CKD status. Am J Kidney Dis 2010;56:651–660.
18.
Ali T, Khan I, Simpson W, Prescott G, Townend J, Smith W, Macleod A: Incidence and outcomes in acute kidney injury: a comprehensive population-based study. J Am Soc Nephrol 2007;18:1292–1298.
© 2012 S. Karger AG, Basel
2012
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