Received October 29, 2008
Accepted on March 13, 2009

ORIGINAL ARTICLES

Nonrecovery of Kidney Function and Death after Acute on Chronic Renal Failure

Chi-yuan Hsu ^*1, Glenn M. Chertow , Charles E. McCulloch , Dongjie Fan , Juan D. Ordoñez ^||, and Alan S. Go ^*

Departments of *Medicine and Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, Department of Medicine, Stanford University, Stanford, and Divisions of Research and ||Nephrology, Kaiser Permanente of Northern California Oakland Medical Center, Oakland, California

¹ To whom correspondence should be addressed. E-mail: hsuchi{at}medicine.ucsf.edu.

	Abstract

Background and objectives: Relatively little is known about clinical outcomes, especially long-term outcomes, among patients who have chronic kidney disease (CKD) and experience superimposed acute renal failure (ARF; acute on chronic renal failure).

Design, setting, participants, & measurements: We tracked 39,805 members of an integrated health care delivery system in northern California who were hospitalized during 1996 through 2003 and had prehospitalization estimated GFR (eGFR) <45 ml/min per 1.73 m². Superimposed ARF was defined as having both a peak inpatient serum creatinine greater than the last outpatient serum creatinine by 50% and receipt of acute dialysis.

Results: Overall, 26% of CKD patients who suffered superimposed ARF died during the index hospitalization. There was a high risk for developing ESRD within 30 d of hospital discharge that varied with preadmission renal function, being 42% among hospital survivors with baseline eGFR 30–44 ml/min per 1.73 m² and 63% among hospital survivors with baseline eGFR 15–29 ml/min per 1.73 m². Compared with patients who had CKD and did not experience superimposed ARF, those who did had a 30% higher long-term risk for death or ESRD.

Conclusions: In a large, community-based cohort of patients with CKD, an episode of superimposed dialysis-requiring ARF was associated with very high risk for nonrecovery of renal function. Dialysis-requiring ARF also seemed to be an independent risk factor for long-term risk for death or ESRD.