Early initiation of dialysis: mortality and renal function recovery in acute kidney injury patients

introduction: the decision of when to start dialysis in acute kidney injury (aki) patients with overt uremia is strongly established, however, when blood urea nitrogen (bun) levels is < 100 mg/dl the timing of initiation of dialysis remains uncertain. purpose: the aim of this study was to assess mortality and renal function recovery aki patients started on dialysis at different bun levels. methods: this was a retrospective study performed at medical school hospital, s？o paulo, brazil, enrolling 86 patients underwent to dialysis. results: dialysis was started when bun < 75 mg/dl in 23 patients (group i) and bun > 75 mg/dl in 63 patients (group ii). hypervolemia and mortality were higher in group i than in group ii (65.2% vs. 14.3% - p < 0.05, 39.1% vs. 68.9%- p < 0.05, respectively). among survivors, the rate of renal function recovery was higher in group i (71.4% and 36.8%, respectively - p < 0.05). multivariate analysis showed that sepsis, age > 60 years, peritoneal dialysis and bun > 75 mg/dl at dialysis initiation were independently related with mortality. conclusions: lower mortality and higher renal function recovery rates were associated with early dialysis initiated at lower bun leves in aki patients.