Predictors of outpatient kidney function recovery among patients who initiate hemodialysis in the hospital

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.