Authors’ view: Renal Replacement Therapy initiation strategies in septic shock and ARDS patients -Stéphane Gaudry, MD, Ph D and Didier Dreyfuss, MD
Stéphane Gaudry (@StephaneG05) and Didier Dreyfuss are physicians in the Critical Care Department at Louis Mourier hospital, Colombes, France (Assistance Publique – Hôpitaux de Paris). They are the authors of AKIKI trial.
Timing of Renal Support and Outcome of Septic Shock and Acute Respiratory Distress Syndrome
The timing of RRT initiation during sepsis-associated acute kidney injury (AKI) is highly debated but the lack of data from large RCTs preclude definitive conclusions. Similarly, the question of RRT initiation during ARDS and severe AKI is crucial regarding the hypothetical better fluid balance management with ultrafiltration.
The recent study published in the AJRCCM was a post-hoc analysis of the AKIKI trial focused on predefined subgroups including ARDS and Septic shock. None of these subgroups derived any significant survival benefit from an early RRT initiation strategy but renal function recovery occurred faster with a delayed strategy. Delayed strategy lead to respectively avoid 45% and 46% of RRT initiation for septic shock and ARDS patients with severe AKI. Moreover, duration of mechanical ventilation for ARDS patients was not influenced by RRT initiation strategy.
The relationships between RRT strategies on one hand and diuresis in the very first days after randomization and renal function recovery on the other were also examined. Starting RRT early was associated with a considerable and highly significant reduction in two-day cumulative urine output and this initial reduction of urine output was associated with delayed renal function recovery. In addition, this study shows that it is wiser to try to control fluid balance with diuretics than with ultrafiltration during RRT in unstable patients, as underlined in the accompanying editorial. Indeed, one can imagine that patients with hemodynamic instability will not respond to diuretics but will suffer from ultrafiltration. On the opposite once stabilized, patients may have an adequate response to diuretic administration making RRT useless if the goal is only the control of fluid balance.
To summarize, initiation of RRT when a patient is not stabilized might further compromise renal function and lead to “Artificial Kidney-Induced Kidney Injury” (AKIKI). A strategy of “permissive hyperuremia” as suggested in the paper 1 may allow for a reduction of iatrogenic injury and lead to considerable savings by limiting the number of undue RRT sessions.
Stéphane Gaudry, MD, Ph D and Didier Dreyfuss, MD
Louis Mourier hospital, Colombes, France