Role of acute kidney injury biomarkers to guide renal replacement therapy initiation, what we learn from EARLY-RRT trial and FST trial?

We wrote this letter to the editor in response to the commentary by Hoste et al., and Meersch et al., on our trial “The effect of early Renal Replacement Therapy guided by plasma Neutrophil Gelatinase Associated Lipocalin on outcome of Acute Kidney Injury: a feasibility study (EARLY-RRT)” trial which was recently published in the J Crit Care (1). In brief, we divided the study into two phases, triage and interventional phase, running subsequently. As a guide for triage to renal replacement therapy (RRT), we measured plasma neutrophil gelatinase associated lipocalin (pNGAL) at the enrollment time. Forty patients with pNGAL ≥400 ng/mL (high pNGAL group) were randomized to ‘early’ or ‘standard’ group. Patients with pNGAL <400 ng/mL (n=20) were defined as low pNGAL group. The triggering pNGAL selected acute kidney injury (AKI) patients with more severity of illness and worse clinical outcome. However, in high pNGAL group, early RRT did not result in different 28-day mortality from the standard group. The median numbers of day free from mechanical ventilation were significantly higher in the early RRT group.