The baseline SCr level was determined as the lowest value among SCr levels on hospital admission and the SCr levels on ICU admission, SCr-MDRD.3Approximately 27.6% of all patients were classified with a baseline SCr-MDRD. For patients with chronic renal insufficiency but not on chronic dialysis, we used the SCr level measured on hospital admission as the baseline figure.
Such differences may be explained by study design, the population studied, differentiation of SCr versus UO criteria, and determination of baseline creatinine level. For example, Hoste and colleagues reported the highest AKI prevalence (i.e. 67%) among 5383 ICU admissions in a retrospective, single center cohort study.3Bagshaw and colleagues, in a retrospective analysis of prospectively collected data, reported a 36.1% AKI prevalence among 120 123 patients in the Australian New Zealand Intensive Care Society Adult Patient Database.6Similarly, when using the Simplified Acute Physiology Score 3 database, Joannidis found 35.5% of patients developed AKI.8Both results were comparable to our study. However, they only defined cases with early AKI, due to laboratory results seen beyond the first 24 or 48 hours of ICU admission. Moreover, some investigators used only SCr or glomerular filtration rate criteria to determine the RIFLE category, due to the lack of 6- or 12-hour UO data.7In comparison, in a 3-month Italian prospective multicenter observational study, only 10.8% (95%CI9.5 to 12.1%) of patients developed AKI.5Another 3-month prospective multicenter study in Greece, using the same study design, observed that 170 patients developed AKI, which corresponding to a prevalence of 16%.19Nevertheless, we believed that the above results were actually comparable to our study. We excluded patients with an ICU length of stay of less than 24 hours, while they were included in the Italian and Greek studies.
Chertow GM, Soroko SH, Paganini EP, Cho KC, Himmelfarb J, Ikizler TA, et al. Mortality after acute renal failure: Models for prognostic stratification and risk adjustment. Kidney Int 2006; 70: 1120-1126.
Nash K, Hafeez A, Hou S. Hospital-acquired renal insufficiency. Am J Kidney Dis 2002; 39: 930-936.
Hoste EA, Clermont G, Kersten A, Venkataraman R, Angus DC, De Bacquer D, et al. RIFLE criteria for acute kidney injury are associated with hospital mortality in critically ill patients: a cohort analysis. Crit Care 2006; 10: R73.
Cruz DN, Bolgan I, Perazella MA, Bonello M, de Cal M, Corradi V, et al. North East Italian prospective hospital renal outcome survey on acute kidney injury (NEiPHROS-AKI): targeting the problem with the RIFLE criteria. Clin J Am Soc Nephrol 2007; 2: 418-425.
Bagshaw SM, George C, Dinu I, Bellomo R. A multi-centre evaluation of the RIFLE criteria for early acute kidney injury in critically ill patients. Nephrol Dial Transplant 2008; 23: 1203-1210.
Joannidis M, Metnitiz B, Bauer P, Schusterschitz N, Moreno R, Druml W, et al. Acute kidney injury in critically ill patients classified by AKIN versus RIFLE using the SAPS 3 database. Intensive Care Med 2009; 35: 1692-1702.
Piccinni P, Cruz DN, Gramaticopolo S, Garzotto F, Dal Santo M, Aneloni G, et al. Prospective multicenter study on epidemiology of acute kidney injury in the ICU: a critical care nephrology Italian collaborative effort (NEFROINT). Minerva Anestesiol 2011; 77: 1072-1083.
Bellomo R, Ronco C, Kellum JA, Mehta RL, Palevsky P; Acute Dialysis Quality Initiative workgroup. 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.
Ricci Z, Cruz D, Ronco C. The RIFLE criteria and mortality in acute kidney injury: a systematic review. Kidney Int 2008; 73: 538-546.
Du B, An Y, Kang Y, Yu X, Zhao M, Ma X, et al. Characteristics of critically ill patients in intensive care units in mainland China. Crit Care Med 2013; 41: 84-92.
Vincent JL, Moreno R, Takala J, Willatts S, De Mendonca A, Bruining H, et al. The SOFA (Sepsis-related Organ Failure Assessment) score to describe organ dysfunction/failure. On behalf of the Working Group on Sepsis-Related Problems of the European Society of Intensive Care Medicine. Intensive Care Med 1996; 22: 707-710.
Bone RC, Balk RA, Cerra FB, Dellinger RP, Fein AM, Knaus WA, et al. Definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. The ACCP/SCCM Consensus Conference Committee. American College of Chest Physicians/Society of Critical Care Medicine. Chest 1992; 101: 1644-1655.
Bernard GR, Artigas A, Brigham KL, Carlet J, Falke K, Hudson L, et al. The American–European Consensus Conference on ARDS. Definitions, mechanisms, relevant outcomes, and clinical trial coordination. Am J Respir Crit Care Med 1994; 149: 818-824.
National Kidney Foundation. K/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Am J Kidney Dis 2002; 39: S1-S266.
Ma YC, Zuo L, Chen JH, Luo Q, Yu XQ, Li Y, et al. Modified glomerular filtration rate estimating equation for Chinese patients with chronic kidney disease. J Am Soc Nephrol 2006; 17: 2937-2944.
Andrikos E, Tseke P, Balafa O, Cruz DN, Tsinta A, Androulaki M, et al. Epidemiology of acute renal failure in ICUs: a multi-center prospective study. Blood Purif 2009; 28: 239-244.
Kohli HS, Bhaskaran MC, Muthukumar T, Thennarasu K, Sud K, Jha V, et al. Treatment-related acute renal failure in the elderly: a hospital-based prospective study. Nephrol Dial Transplant 2000; 15: 212-217.
Uchino S, Kellum JA, Bellomo R, Doig GS, Morimatsu H, Morgera S, et al. Acute renal failure in critically ill patients: a multinational, multicenter study. JAMA 2005; 294: 813-818.
Bagshaw SM, Uchino S, Bellomo R , Morimatsu H, Morgera S, Schetz M, et al. Septic acute kidney injury in critically ill patients: clinical characteristics and outcomes. Clin J Am Soc Nephrol 2007; 2: 431-439.
Neveu H, Kleinknecht D, Brivet F, Loirat P, Landais P. Prognostic factors in acute renal failure due to sepsis: results of a prospective multicenter study. The French Study Group on Acute Renal Failure. Nephrol Dial Transplant 1996; 11: 293-299.
Mehta RL, Bouchard J, Soroko SB, Ikizler TA, Paganini EP, Chertow GM, et al. Sepsis as a cause and consequence of acute kidney injury: Program to Improve Care in Acute Renal Disease. Intensive Care Med 2011; 37: 241-248.
Oppert M, Engel C, Brunkhorst FM, Bogatsch H, Reinhart K, Frei U, et al. Acute renal failure in patients with severe sepsis and septic shock – a significant independent risk factor for motatlity: results from the German Prevalence Study. Nephrol Dial Transplant 2008; 23: 904-909.
Herget-Rosenthal S, Marggraf G, Husing J, Goring F, Pietruck F, Janssen O, et al. Early detection of acute renal failure by serum cystatin C. Kidney Int 2004; 66: 1115-1122.
Solomon AW, Kirwan CJ, Alexander ND, Nimako K, Jurukov A, Forth RJ, et al. Urine output on an intensive care unit: case-control study. BMJ 2010; 341: c6761.
Macedo E, Malhotra R, Claure-Del Granado R, Fedullo P, Mehta RL. Defining urine output criterion for acute kidney injury in critically ill patients. Nephrol Dial Transplant 2011; 26: 509-515.
Wlodzimirow KA, Abu-Hanna A, Slabbekoorn M, Chamuleau RA, Schultz MJ, Bouman CS. A comparison of RIFLE with and without urine output criteria for acute kidney injury in critically ill patients. Crit Care 2012; 16: R200.
Cerda J. Oliguria: an earlier and accurate biomarker of acute kidney injury? Kidney Int 2011; 80: 699-701.
Mehta RL, Kellum JA, Shah SV, Molitoris BA, Ronco C, Warnock DG, et al. Acute kidney injury network: report of an initiative to improve outcomes in acute kidney injury. Crit Care 2007; 11: R31.
Lopes JA, Fernandes P, Jorge S, Gonçalves S, Alvarez A, Costa e Silva Z, et al. Acute kidney injury in intensive care unit patients: a comparison between the RIFLE and the Acute Kidney Injury Network classifications. Crit Care 2008; 12: R110.
Siew ED, Matheny ME, Ikizler TA, Lewis JB, Miller RA, Waitman LR, et al. Commonly used surrogates for baseline renal function affect the classification and prognosis of acute kidney injury. Kidney Int 2010; 77: 536-542.
Cruz DN, Ricci Z, Ronco C. Clinical review: RIFLE and AKIN – time for reappraisal. Crit Care 2009; 13: 211.