Timing of Renal Support and Outcome of Septic Shock and Acute Respiratory Distress Syndrome. A Post Hoc Analysis of the AKIKI Randomized Clinical Trial.

RATIONALE: The optimal strategy for initiation of renal replacement therapy (RRT) in patients with severe acute kidney injury in the context of septic shock and acute respiratory distress syndrome (ARDS) is unknown.

OBJECTIVES: To examine the effect of an early compared with a delayed RRT initiation strategy on 60-day mortality according to baseline sepsis status, ARDS status, and severity.

METHODS: Post hoc analysis of the AKIKI (Artificial Kidney Initiation in Kidney Injury) trial.

MEASUREMENTS AND MAIN RESULTS: Subgroups were defined according to baseline characteristics: sepsis status (Sepsis-3 definition), ARDS status (Berlin definition), Simplified Acute Physiology Score 3 (SAPS 3), and Sepsis-related Organ Failure Assessment (SOFA). Of 619 patients, 348 (56%) had septic shock and 207 (33%) had ARDS. We found no significant influence of the baseline sepsis status (P = 0.28), baseline ARDS status (P = 0.94), and baseline severity scores (P = 0.77 and P = 0.46 for SAPS 3 and SOFA, respectively) on the comparison of 60-day mortality according to RRT initiation strategy. A delayed RRT initiation strategy allowed 45% of patients with septic shock and 46% of patients with ARDS to escape RRT. Urine output was higher in the delayed group. Renal function recovery occurred earlier with the delayed RRT strategy in patients with septic shock or ARDS (P < 0.001 and P = 0.003, respectively). Time to successful extubation in patients with ARDS was not affected by RRT strategy (P = 0.43).

CONCLUSIONS: Early RRT initiation strategy was not associated with any improvement of 60-day mortality in patients with severe acute kidney injury and septic shock or ARDS. Unnecessary and potentially risky procedures might often be avoided in these fragile populations. Clinical trial registered with www.clinicaltrials.gov (NCT 01932190).