DEFINITION, CLASSIFICATION AND DIAGNOSIS OF ACUTE KIDNEY INJURY JOSÉ ANTÓNIO LOPES, MD, PhD Faculty of Medicine, University of Lisbon Department of Nephrology and Renal Transplantation Centro Hospitalar Lisboa Norte, EPE, Lisboa, Portugal jalopes93@hotmail.com Athens, March 11 2017
No conflict of interests
DEFINITION AND CLASSIFICATION OF AKI INCIDENCE DEFINITIONS MORTALITY MORTALITY
DEFINITION OF AKI INCIDENCE AND MORTALITY N=9.210 Chertow GM et al. J Am Soc Nephrol 2005
DEFINITION OF AKI 1. Easy to use 2. High sensitivity and specificity in settings 3. Consider variations in baseline SCr 4. Acute-on-chronic phenomenon 5. Determine AKI severity 6. Identifiy early and late AKI
RIFLE Classification Risk, Injury, Failure, Loss, End-stage kidney disease Sudden (1-7 days) and >24h Baseline SCr known (if unknown GFR 75 ml/min/1.73m 2 ) Bellomo R et al. Crit Care 2004
18% 67% 36% 11% 36% Lopes JA et al. Clin Kidney J 2013
VALIDATION OF THE RIFLE IN THE ICU Risk Injury Failure Ricci Z et al. Kidney Int 2008
AKI IN CRITICALLY ILL SEPTIC PATIENTS SAPS II RIFLE 0.778 0.750 Lopes JA et al. Crit Care 2007
CRITICALLY ILL PATIENTS Hoste E et al. Crit Care 2006
AKIN CLASSIFICATION Acute Kidney Injury Network After achieving an adequate hydration status and excluding urinary obstruction Mehta RL et al. Crit Care 2007
ΔSCr 0.3 mg/dl - IN-HOSPITAL MORTALITY N=9.210 Chertow GM et al. J Am Soc Nephrol 2005
N=662 P = 0.018 Lopes JA et al. Crit Care 2008
N=662 Lopes JA et al. Crit Care 2008
Acute kidney injury in critically ill patients classified by AKIN versus RIFLE using the SAPS 3 database N=16.784 Joannidis M et al. Intensive Care Med 2009
LIMITATIONS OF THE RIFLE AND AKIN URINE OUTPUT Sensitivity and specificity Hourly basis register (+++ ICU) SCr variability in endogenous production and S release Multiple factors can interfer with SCr determination Hemodilution Sepsis production CKD late in SCr Marker of renal function and not of lesion
LIMITATIONS OF THE RIFLE AND AKIN Baseline SCr RIFLE CKD overestimation of AKI AKIN Increase in SCr >48h Stage 3 (SCr, UO, RRT) MDRD equation CKD late elevation of SCr Etiology and RRT not considered No origin information
RIFLE 2004 AKIN 2007 LIMITATIONS STRENGTHS KDIGO 2012
KDIGO CLASSIFICATION KDIGO Clinical Practice Guideline for AKI. Kidney Int 2012
N=49.518 Fujii T et al. Clin J Am Soc Nephrol 2014
Roy AK et al. Cardiorenal Med 2013
N=457 Pereira M et al. Clin Kidney J 2016
N=457 Pereira M et al. Clin Kidney J 2016
Pereira M et al. Clin Kidney J 2016
BIOMARKERS IN AKI Adapted from Ostermann M et al. Crit Care 2016
BIOMARKERS IN AKI Adapted from Coca SG et al. Kidney Int 2008
FRAMEWORK FOR EVALUATING AKI BASED ON BIOMARKERS Adapted from Murray PT et al. Kidney Int 2013
BIOMARKERS IN AKI FUTURE DIRECTIONS Confirm that the proposed expansion of the diagnostic criteria for AKI to include the isolated presence of damage biomarkers, with preserved function, is clinically relevant. Determine the mechanistic pathways that are involved in the development of AKI and its natural course. Define the prognostic value of the combined use of functional and damage markers in sequential measurements to confirm the prognostic significance of these categories. Ascertain how well the combination of damage and functional markers can improve recognition of AKI in the setting of CKD. Murray PT et al. Kidney Int 2013
BIOMARKERS IN AKI FUTURE DIRECTIONS Large population-based studies would be required across multiple centers enrolling patients in the wide spectrum of AKI and different disease states, to determine whether operationalizing the approach to AKI with a simple 2x2 table to mechanistically define AKI cases and their evolution usefully influences patient management and ultimately improves outcomes. Discover and confirm the sensitivity and specificity of damage and functional markers for specific situations. Establish standard techniques for collection, handling, and presentation of biomarker data that permit appropriate interpretation across settings. Murray PT et al. Kidney Int 2013
Adapted from Ostermann M et al. Crit Care 2016
Adapted from Ostermann M et al. Crit Care 2016
Adapted from Johnson RJ, Feehally J, Floege F. Comprehensive Clinical Nephrology 5 th ed. 2015
CONCLUSIONS The RIFLE and the AKIN classifications allowed the identification of a large proportion of patients as having AKI and have shown a good prognostic ability in determining hospital mortality. The modifications proposed to RIFLE did not materially improve its prognostic accuracy. The KDIGO work group has made the fusion of the RIFLE and AKIN classifications in order to establish one classification of AKI for practice, research, and public health. The conceptual framework of functional and damage biomarkers will need to be validated through future studies, and additional evidence will be required to establish their best combinations for utilization in clinical practice.