AB-
Organic ARF
Measurement of renal function
Predictors of Outpatient Kidney Function Recovery Among Patients
Who Initiate Hemodialysis in the Hospital
LaTonya J. Hickson, MD correspondence mail ; Sanjay Chaudhary, MBBS ; Amy W. Williams,
MD ; John J. Dillon, MD et al.
Journal : American Journal of Kidney Diseases
Year : 2015 / Month : April
Volume 65
Pages 592–602
ABSTRACT
Background
Recent policy clarifications by the Centers for Medicare & Medicaid Services have changed
access to outpatient dialysis care at end-stage renal disease (ESRD) facilities for individuals with
acute kidney injury in the United States. Tools to predict “ESRD” and “acute” status in terms of
kidney function recovery among patients who previously initiated dialysis therapy in the hospital
could help inform patient management decisions.
Study Design
Historical cohort study.
Setting & Participants
Incident hemodialysis patients in the Mayo Clinic Health System who initiated in-hospital renal
replacement therapy (RRT) and continued outpatient dialysis following hospital dismissal (2006
through 2009).
Predictor
Baseline estimated glomerular filtration rate (eGFR), acute tubular necrosis from sepsis or
surgery, heart failure, intensive care unit, and dialysis access.
Outcomes
Kidney function recovery defined as sufficient kidney function for outpatient hemodialysis therapy
discontinuation.
Results
Cohort consisted of 281 patients with a mean age of 64 years, 63% men, 45% with heart failure,
and baseline eGFR ≥ 30 mL/min/1.73 m2 in 46%. During a median of 8 months, 52 (19%)
recovered, most (94%) within 6 months. Higher baseline eGFR (HR per 10–mL/min/1.73 m2
increase eGFR, 1.27; 95% CI, 1.16-1.39; P < 0.001), acute tubular necrosis from sepsis or
surgery (HR, 3.34; 95% CI, 1.83-6.24; P < 0.001), and heart failure (HR, 0.40; 95% CI, 0.19-0.78,
P = 0.007) were independent predictors of recovery within 6 months, whereas first RRT in the
intensive care unit and catheter dialysis access were not. There was a positive interaction
between absence of heart failure and eGFR ≥ 30 mL/min/1.73 m2 for predicting kidney function
recovery (P < 0.001).
Limitations
Sample size.
Conclusions
Kidney function recovery in the outpatient hemodialysis unit following in-hospital RRT initiation is
not rare. As expected, higher baseline eGFR is an important determinant of recovery. However,
patients with heart failure are less likely to recover even with a higher baseline eGFR.
Consideration of these factors at hospital discharge informs decisions on ESRD status
designation and long-term hemodialysis care.
Index Words: Acute kidney injury (AKI), renal replacement therapy (RRT), hospitalization,
transition to outpatient dialysis, acute on chronic kidney disease, risk factors, renal recovery,
reversible renal injury, discontinuation of dialysis, kidney function prognosis, end-stage renal
disease (ESRD), heart failure.
COMMENTS
Possible outcomes for patients with acute kidney insufficiency (AKI) include death; complete
recovery of kidney function; or development of progressive chronic kidney disease (CKD), AKI on
CKD, or irreversible loss of kidney function leading to end-stage renal disease (ESRD). Among
survivors of this high-risk event, as many as 13% to 32% require dialysis at the time of hospital
discharge.
The primary outcome of interest of this study was recovery of sufficient kidney function to
discontinue outpatient HD therapy. Of note, close to 60% of the outpatient HD cohort started
dialysis treatment in the hospital setting. This fact should serve to alert the nephrology community
about AKI’s importance as a source of incident outpatients who require in-center HD, and the
value of early diagnosis of AKI and accurate identification of prognostic predictors. The
unfavorable outcome of postdischarge RRT might be linked to the late detection of AKI when
using only serum creatinine as a marker of AKI.
In this study, within baseline kidney function subgroups, the distribution of patients included AKI
(15%), AKI on CKD (55%), CKD stage 5 (20%), and acuity unknown (10%). The AKI group
generally was younger and had fewer comorbid conditions, more therapy initiation in the ICU, and
longer hospital stays. most of the patients who recovered enough kidney function to discontinue
dialysis did so by 3 months (73%) and 6 months (94%) after RRT initiation. The remainder of the
patients recovered kidney function by 12 months. Specific independent predictors of kidney
function recovery have been outlined: higher baseline estimated glomerular filtration rate (eGFR),
sepsis/postoperative acute tubular necrosis, and absence of heart failure. Another important
finding was that none of the patients with CKD stage 5 recovered kidney function.
Patients with eGFRs ≥ 30 mL/min/1.73 m2 had a 7.5-fold higher likelihood of recovery. Following
adjustment for ICU initiation, catheter access, sepsis/postoperative ATN, and heart failure, this
relationship was preserved (HR, 5.86; P < 0.001].
To conclude, this study must be analyzed in the scope of health organisation and offer of dialysis
facilities since each country has its own organisation. We have to recognize that only in-hospital
centers offer all the facilities need to treat all forms of AKI. Identification of new outpatient
hemodialysis who initiated RRT in the hospital and who may recover kidney function is important.
In particular, higher baseline eGFR is a potent predictor of recovery in the absence of heart
failure. Because we lack biomarkers to distinguish acute reversible from chronic irreversible
kidney injury, uncertainty in the designation of ESRD in such patients should be recognized not
only by patients and providers, but also by payers.
Pr. Jacques CHANARD
Professor of Nephrology