[Impact of therapeutic time on the prognosis in critically ill patients with acute renal failure who needed renal replacement therapy].

Objective: To investigate the impact of therapeutic time on the prognosis in critically ill patients with acute renal failure (ARF) who needed renal replacement therapy (RRT), and to analyze the risk factors of death.

Methods: All data were retrieved from the Database of Early Diagnosis and Treatment in Acute Renal Failure in Shanghai. Eighty-eight patients were collected with 56 males and 32 females who accepted continuous veno-venous hemofiltration (CVVH). The mean age was (55.73 ± 16.33) years old. Patients were divided into two groups according to therapeutic time: short time group (6-12 hours, n=49) and long time group (>12 hours, n=39). The differences between two groups before and after treatment were compared. Kaplan-Meier survival analysis, the Log-rank test was performed to evaluate the prognosis of ARF patients on 15, 30 and 60 days. Cox regression analysis was performed to evaluate the risk factors affected the patient survival.

Results: There were no significant difference of age, surgery, chronic kidney disease (CKD), diabetes, multiple organ failure (MOF) and severity of disease between two groups before treatment. Compared with that before treatment, blood pH, HCO(-)(3) were increased, and K(+), blood urea nitrogen (BUN), serum creatinine (SCr) were decreased after treatment (all P <0.05). There were no significant difference of Na(+) concentration and heart rate (HR), mean arterial pressure (MAP) after treatment. Kaplan-Meier survival analysis showed the survival rate of short time group and long time group were 64.4% vs. 51.4%, 52.8% vs. 46.2% and 50.4% vs.41.0% on 15, 30 and 60 days respectively. No significant difference in survival rate was noted (P=1.234). Cox regression analysis showed that the independent risk factors of short time mortality were diabetes [hazard ratio (HR)=2.134, 95% confidence interval (95%CI) 1.093-4.167,P<0.05] and MOF(HR 1.564, 95%CI 1.233-1.984,P<0.01).

Conclusion: The mortality of ARF in critical ill patients remains high, despite accepted renal replacement therapy. The therapeutic time of CVVH may not affect the patient survival not with standing the duration of renal replacement therapy. In our group, diabetes and MOF were the independent risk factors of patients death.