Strategies for the optimal timing to start renal replacement therapy in critically ill patients with acute kidney injury

Abstract

Renal replacement therapy (RRT) is increasingly utilized to support critically ill patients with severe acute kidney injury (AKI). The question of whether and when to start RRT for a critically ill patient with AKI has long troubled clinicians. When severe complications of AKI develop, the need to commence RRT is unambiguous. In the absence of such complications but in the presence of severe AKI, the optimal time and thresholds for starting RRT are uncertain. The majority of existing data have largely been derived from observational studies. These have been limited due to confounding by indication, considerable heterogeneity in case mix and illness severity, and variably applied definitions for both AKI and for how "timing" was anchored relative to starting RRT. It is unclear whether a preemptive or earlier strategy of RRT initiation aimed largely at avoiding complications related to AKI or a more conservative strategy where RRT is started in response to developing complications leads to better patient-centered outcomes and health services use. This question has been the focus of 2 recently completed randomized trials. In this review, we provide an appraisal of available evidence, discuss existing knowledge gaps, and provide perspective on future research that will better inform the optimal timing of RRT initiation in AKI.

Comparison between watchful waiting strategy and early initiation of renal replacement therapy in the critically ill acute kidney injury population: an updated systematic review and meta-analysis

“…A higher NGAL level is now considered a marker of poor prognosis. According to Bagshaw et al, some severely critically ill patients are unlikely to benefit from early RRT, and several potential drawbacks should be considered, such as higher costs or unnecessary complications from dialysis [74]. Several studies in this field used plasma NGAL as their enrollment criterion.…”

Acute kidney injury: Epidemiology, outcomes, complications, and therapeutic strategies

“…Despite previous studies investigating the relationship between mortality and the timing of RRT initiation, it remained controversial whether early initiation of RRT improved outcomes. In 2016, two RCTs and in 2017 nine systematic reviews and meta‐analyses evaluated the optimal timing of RRT initiation for AKI. A multicenter RCT study, the Artificial Kidney Initiation in Kidney Injury (AKIKI) study, conducted in France, showed that there were no significant differences in mortality between early and late initiation of RRT .…”

“…Early initiation of RRT (defined as KDIGO stage 3 AKI) in the AKIKI study corresponded to the delayed arm in the ELAIN study. Turning to the conclusions of nine meta-analyses,[90][91][92][93][94][95][96][97][98] the AKI patients in the RCTs who underwent early initiation of RRT did not show a lower mortality rate than those with late RRT [90][91][92][93][94]96,98.…”

Haste makes waste—Should current guideline recommendations for initiation of renal replacement therapy for acute kidney injury be changed?

“…The consequences of blood‐membrane interactions are uncertain but may well be harmful. Especially in CRRT, there is a risk for development of hypophosphatemia which can lead to muscle weakness and prolonged respiratory failure which is associated with higher mortality . In observational trials, use of RRT is independently associated with mortality .…”

“…Especially in CRRT, there is a risk for development of hypophosphatemia which can lead to muscle weakness and prolonged respiratory failure which is associated with higher mortality. [22][23][24] In observational trials, use of RRT is independently associated with mortality. 20,21,[25][26][27][28] A too early start can thus be harmful.…”