Publication – S. Gaudry et al. The Lancet

Delayed versus early initiation of renal replacement therapy for severe acute kidney injury: a systematic review and individual patient data meta-analysis of randomised clinical trials.

This study recently published in the Lancet is an individual patient data meta-analysis (IPDMA) of randomised clinical trials evaluating initiation strategies for renal replacement therapy (RRT) in the context of severe acute kidney injury.

Indeed, there is intense debate on this timing: some advocate to start RRT as soon as the AKI is severe (early strategy) whereas others consider that withholding RRT in the absence of complications (severe hyperkalemia or acidosis or pulmonary congestion) is a better choice (delayed strategy).

Several important RCTs on the timing of RRT were published in the recent years (including the AKIKI trial in NEJM by our team). The bulk of evidence from these studies favours a delayed strategy which allows avoiding useless and potentially dangerous procedures in an important number of patients (but does not affect mortality). No meta-analysis on individual data was ever performed. Indeed, previous meta-analyses (including from The Cochrane Collaboration) were done on study level and yielded inconsistent results.

This IPDMA included 9 recent (<10 years) trials (2083 patients) with a low risk of bias. It shows with a high level of evidence that mortality was not reduced by a strategy of early RRT initiation in patients with severe acute kidney injury. Then, in the absence of urgent indication (life-threatening metabolic complication), initiation of RRT may be safely postponed. Delaying RRT initiation with close patient monitoring led to a reduced use of RRT which allows for resource saving.

In the present context of COVID-19 crisis, this study could not have come at a better time since limiting overuse of RRT may be useful to prevent consumable shortage.