Timing for Initiation of Continuous Renal Replacement Therapy in Patients With Septic Shock and Acute Kidney Injury

The optimal timing for renal replacement therapy initiation in septic acute kidney injury (AKI) remains controversial. This study investigates the impact of early versus late initiation of continuous renal replacement therapy (CRRT) on organ dysfunction among patients with septic shock and AKI. Patients were dichotomized into early (simplified RIFLE Risk) or late (simplified RIFLE Injury or Failure) CRRT initiation. Patients with chronic kidney disease stage 5 or those on long-term dialysis were excluded. Organ dysfunction was quantified by Sequential Organ Failure Assessment (SOFA) score. From January 2008 to June 2011, 120 patients fulfilled the inclusion criteria. Thirty-one (26%) underwent early while 89 (74%) had late CRRT. No significant difference was noted between groups on improvement of total SOFA/non-renal SOFA score or noradrenaline equivalent in the first 24 and 48h after CRRT initiation. Dialysis requirement and mortality (at 28 days, 3 months and 6 months) did not differ. In conclusion, improvement of non-renal SOFA score 48h after CRRT correlated with SOFA score on CRRT initiation (P=0.040) and APACHE IV risk of death (P=0.000), but not estimated glomerular filtration rate on CRRT initiation (P=0.377). Improvement of non-renal SOFA score correlated with SOFA score on CRRT initiation and APACHE IV risk of death. However, this retrospective review cannot identify any significant clinical benefit of early CRRT initiation in patients presenting with septic shock and AKI.