Transcript Predicting aKI Is more challenging as Age Progresses

PREDICTING AKI IS
MORE CHALLENGING
AS AGE PROGRESSES
Sandra Kane-Gill, PharmD, MSc
Associate Professor, School of Pharmacy
Co-Investigators
• Florentina Sileanu, BS, PhD candidate
• Greg Trieteley, PharmD candidate
• Ragi Marugan, MD
• Steven Handler, MD
• John Kellum, MD
Putting the Problem in Context
• Acute kidney injury (AKI)
• Develops over hours to days in either community or hospitalized patients
• Incidence of AKI doubled from 2000 to 2009
• Outcomes:
• Length of stay 2.4 times longer
• Hospital mortality rates as high as 60% in ICU patients and over 80% in patients requiring renal
replacement therapies
• AKI predisposes patients to progression of chronic kidney disease and end-stage renal disease
• Risk factors:
• Advanced age (>65 y.o.)
• Organ failure
• Sepsis and infection
• Cardiac shock
• Pre-existing chronic medical conditions
• Nephrotoxic drugs
• Obesity
• Surgery
• Transplantation
• Recent rise in AKI contributed to the growing elderly population
Himmerlfarb J. Semin Nephrol 2009;29:658-664.
Wang WE et al. Am J Nephrol 2012;35:349-55.
Coca SG et al. Nephron Clin Prac 2011;119:suppl 1:c19-24
RESEARCH QUESTION
Will the risk factors or model of prediction be
upheld in the elderly population?
Study Design and Sample:
Retrospective cohort study from July 2000-June 2008
45,655
3,762
105
1,340
494
16
39,938
• 7 ICUs with greater than 120 beds
• Receiving hemodialysis or rental transplant prior to hospitalization
• Baseline serum creatinine ≥ 4
• Underwent liver transplantation prior to hospitalization
• Inadequate information to determine AKI status
• Unknown age
• Included in analysis
Methods
• Data were obtained from the Medical Archival Repository
System (MARS)
• International Classification Diseases, 9th edition (ICD9)
• Diagnosis related group (DRG)
• Severity of illness (APCHE III)
• Sepsis (blood culture and antibiotic in 24h of each other)
• Hypotensive index
• Baseline serum creatinine
• Admission creatinine
• Reference creatinine
• GFR (mL/min/1.73 m2) = 175 × (Scr)-1.154 × (Age)-0.203 × (0.742 if
female) × (1.212 if African American) (conventional units)
• eGFR of 75ml/min/1.73m2 when baseline creatinine missing
Methods
• Categorized by age (≥ 65 y.o.)
• Cohort evaluated for patients who developed AKI
• AKI classification according to KDIGO
Analysis
• Prevalence compared by group and then by year
• Outcome comparison
• Mortality
• Recovery from renal replacement therapy (RRT)
• 90 and 365 days after first RRT and alive but not in United States Renal
Data System
• Risk factor assessment completed using a multivariate
logistic regression model
• Impact of age
• Separate assessment by age group
Results
AKI Stages by Age Group (p <0.001)
Age < 65
Age ≥ 65
50.0%
Percent in AKI Stage within Age Group
6,020
(48.4%)
40.0%
5,476
(43.2%)
30.0%
4,084
(32.2%)
3,557
(28.6%)
3,114
20.0%
(24.6%)
2,869
(23.1%)
10.0%
0.0%
Stage1
Stage2
max RIFLE Stage (KDIGO)
Stage3
Results
Percent in AKI Stage within Year
AKI Stages by Year in Age < 65
50.0%
45.0%
40.0%
35.0%
30.0%
25.0%
20.0%
15.0%
10.0%
5.0%
0.0%
2000
2001
2002
no AKI
2003
2004
Stage1
2005
2006
Stage2
2007
Stage3
2008
Results
AKI Stages by Year in Age ≥ 65
Percent in AKI Stage within Year
50.0%
40.0%
30.0%
20.0%
10.0%
0.0%
2000
2001
no AKI
2002
2003
Stage1
2004
2005
Stage2
2006
2007
Stage3
2008
Comparison of Outcomes by Age for
Patients with Acute Kidney Injury
Multivariable regression analysis of risk factors
for AKI patients compared to non-AKI patients
Multivariable regression analysis of risk factors
for AKI patients compared to non-AKI patients
(≥ 65 and <65)
Age ≥65; N = 15,542; AKI developed on or after
ICU admission; AUC 0.673
Outcome: AKI
Age < 65
OR
-
95% C.I.for OR
-
Race
p-value
-
Age < 65; N = 19,812; AKI developed on or
after ICU admission; AUC 0.719
OR
-
95% C.I.for OR
-
.002
p-value
<0.001
Black vs. White
1.035
.880
1.218
.675
1.052
.945
1.171
.359
Other vs. White
1.212
1.088
1.349
<0.001
1.255
1.140
1.382
<0.001
Diabetes
1.179
1.011
1.374
.035
1.295
1.111
1.509
.001
Cardiac Disease
1.192
1.050
1.354
.007
1.590
1.381
1.830
<0.001
Surgical
1.072
0.995
1.154
.068
1.117
1.048
1.189
.001
Sepsis (24hrs from ICU day 1)
2.549
2.165
2.999
<0.001
2.917
2.601
3.271
<0.001
Vasopressors (24hrs from ICU day 1)
1.906
1.716
2.117
<0.001
2.011
1.831
2.209
<0.001
2.081
1.927
2.247
<0.001
2.519
2.365
2.682
<0.001
<30 vs >60
2.012
1.542
2.625
<0.001
3.161
2.261
4.420
<0.001
[30-60] vs >60
1.461
1.293
1.651
<0.001
2.530
2.161
2.961
<0.001
1.006
1.004
1.008
<0.001
1.010
1.008
1.013
<0.001
1.075
0.990
1.167
.084
1.469
1.357
1.590
<0.001
Mechanical Ventilation (24hrs from ICU day 1)
eGFR
Hypotensive Index (24hrs from ICU admission)
History of hypertension
<0.001
<0.001
Comparison of AUC for Elderly vs Younger
Conclusion
• From previous studies, we know age is an independent risk
factor for AKI and this study provides confirmation
• Younger patients are less likely to develop AKI compared to
elderly patients, but their in-hospital outcomes are similar,
though their prolonged recovery is slightly improved
• Likelihood of developing AKI increases with age; but the ability
to predict patients at risk for AKI declines with age using an
established set of risk factors
• Automation may assist with identification of patients at risk for
AKI, especially considering the current challenges