Background: Acute kidney injury (AKI) is a common complication that occurs in seriously ill patients admitted to the ICU, and many of these patients eventually require RRT. When complicated by major metabolic disorders, it is usually clear when therapy should be initiated. However, when these complications are absent, the most appropriate time to initiate RRT is unclear. There are potential advantages to performing early RRT in patients with severe AKI, such as restoring acid-base balance, preventing fluid accumulation, and preventing major electrolyte disturbances.
Dr. Andrew Kim
Study design: Multinational, randomized, controlled trial.
Setting: 168 hospitals in 15 countries.
Synopsis: Eligible patients were adults admitted to an ICU with severe AKI. Patients were randomly assigned to an accelerated strategy of RRT (initiated within 12 hours, 1,465 patients) or a standard strategy of RRT (held until conventional indications developed or AKI lasted more than 72 hours, 1,462 patients). RRT was performed in 1,418 (96.8%) in the accelerated group and 903 (61.8%) in the standard group. At 90 days, 643 deaths (43.9%) occurred in the accelerated group and 639 deaths (43.7%) occurred in the standard group (RR, 1.00; 95% CI, 0.93-1.09; P = .92). Among survivors at 90 days, 85 out of 814 accelerated patients (10.4%) and 49 of 815 standard patients (6.0%) continued to require RRT (RR, 1.75; 95% CI, 1.24-2.43), suggesting the possibility of increased dependence on long-term RRT if introduced early. Limitations include use of clinical equipoise to confirm full eligibility, introducing possible patient heterogeneity into the trial. In addition, broad discretion was given to clinicians on when to start RRT in the standard group resulting in variable initiation times.
Bottom line: In critically ill patients with severe AKI, earlier RRT did not result in lower mortality at 90 days compared with standard therapy and increased the risk of requiring RRT at 90 days.
Citation: Bagshaw SM et al. Timing of initiation of renal-replacement therapy in acute kidney injury. N Engl J Med. 2020;383:240-51. doi: 10.1056/NEJMoa2000741.
Dr. Kim is a hospitalist in the Division of Hospital Medicine, Mount Sinai Health System, New York.
