Early versus late renal replacement therapy in acute kidney injury: the search for a definition of timing continues

Excerpt

We read with interest the systematic review by Karvellas and colleagues on early versus late renal replacement therapy (RRT) in critically ill patients with acute kidney injury (AKI) [1]. The authors rightly cite enormous heterogeneity between the 15 studies reviewed as a key concern. We would like to focus on the varied approach and lack of consensus in defining early and late initiation of RRT, as all of the 15 studies quote different definitions in their methods. Even those utilising similar markers and criteria for AKI - for example, the RIFLE criteria [2] (two studies) or blood urea and nitrogen (four studies) - utilised and interpreted them in very different ways when distinguishing early and late initiation of RRT. …