Acute Renal Injury: What Now? Patricia F. Kao, MD MS Assistant Professor Department of Nephrology and Hypertenstion Department of Physiological Sciences Eastern Virginia Medical School

Disclosures 

I have no Conflict of Interests to Disclose

Learning Objectives 

By the end of this lecture, you should:  Understand

controversies in the evaluation and management of acute kidney injury

Terminology Acute Kidney Injury (AKI)?

Terminology 

For the remainder of this lecture, I will use the term “Acute Kidney Injury”, abbreviated as (AKI), which is currently the most widely accepted term used by the nephrology community.

Brief Outline – Acute Kidney Injury 

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Epidemiology Definitions and classification of AKI Diagnosis and Evaluation Treatment and Management of AKI The focus for this talk will be on advances and controversies over the last 2 decades in each of these areas, rather than a comprehensive review

Epidemiology

From: Hsu et al. Kidney Int. 2007;72(2):208–212

vol 1 Figure 5.2 Unadjusted rates of first hospitalization with AKI for Medicare patients aged 66+ by age and year, 2003-2012

Vol 1, CKD, Ch 5

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vol 1 Figure 5.4 Unadjusted rates of first hospitalization with AKI for Medicare patients aged 66+ by CKD, DM and year, 2003-2012

Vol 1, CKD, Ch 5

10

Epidemiology of AKI 

Most epidemiologic studies have shown an increase in the annual incidence of AKI over the last 2 decades, however the actual incidence rates of AKI reported are anywhere from 1%-25% of critically ill patients (Chertow et al, 1998; de Mendonca et al, 2000)

Epidemiology of AKI 

The wide range of data reported is likely due to differences in: the criteria used to dx AKI (different laboratory criteria, classification systems, and ICD-9 codes)  heterogeneity in the etiology of AKI  characteristics of the study populations 

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This creates significant challenges in comparing trials of prevention and therapy

Epidemiology of AKI 

Regardless of disparate incidence rates in the literature, there is a change in the paradigm of AKI. Whereas it was previously thought that AKI and CKD were separate entities, it is now understood that: 

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AKI is a major risk factor for chronic kidney disease (CKD) Significant increase in the long-term risk of CKD and ESRD following AKI, even after initial recovery of renal function AKI is an independent risk factor for mortality

From: The 2012 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline for acute kidney injury (AKI)

vol 1 Figure 5.7 Cumulative probability of a recurrent AKI hospitalization within two years of live discharge from first AKI hospitalization in 2010 for Medicare patients aged 66+

Vol 1, CKD, Ch 5

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vol 1 Figure 5.13 Renal status one year following discharge from AKI hospitalization in 2010-2011, among surviving Medicare patients aged 66+ without kidney disease prior to AKI hospitalization, by CKD stage and ESRD status

Vol 1, CKD, Ch 5

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Acute kidney injury increases risk of ESRD among elderly

N= 233.803

Ishani A A et et al. al. J Am SocSoc Nephrol 2009 Ishani J Am Nephrol 2009

AKI and Mortality Rates 

Xue et al. published a study in 2006 showing:  In-hospital

mortality rates of:

 33%

in AKI pts requiring dialysis  27.5% in AKI pts not requiring dialysis  4.6% in pts with no AKI  90-day

mortality rates of:

 44.8%

in AKI pts requiring dialysis  40.3% in AKI pts not requiring dialysis  12.1% in pts with no AKI

AKI and Mortality Rates •AKI (Δ in SCr >0.5) •Age (per 10 yr) •CKD •CV dis. •Respiratory dis •GI dis. •Cancer •Infection

6.5 1.7 2.5 1.5 3 2.4 2.9 7.5