Intensity of renal support in critically ill patients with acute kidney injury

Abstract

Background: The optimal intensity of renal-replacement therapy in critically ill patients with acute kidney injury is controversial.

Methods: We randomly assigned critically ill patients with acute kidney injury and failure of at least one nonrenal organ or sepsis to receive intensive or less intensive renal-replacement therapy. The primary end point was death from any cause by day 60. In both study groups, hemodynamically stable patients underwent intermittent hemodialysis, and hemodynamically unstable patients underwent continuous venovenous hemodiafiltration or sustained low-efficiency dialysis. Patients receiving the intensive treatment strategy underwent intermittent hemodialysis and sustained low-efficiency dialysis six times per week and continuous venovenous hemodiafiltration at 35 ml per kilogram of body weight per hour; for patients receiving the less-intensive treatment strategy, the corresponding treatments were provided thrice weekly and at 20 ml per kilogram per hour.

Results: Baseline characteristics of the 1124 patients in the two groups were similar. The rate of death from any cause by day 60 was 53.6% with intensive therapy and 51.5% with less-intensive therapy (odds ratio, 1.09; 95% confidence interval, 0.86 to 1.40; P=0.47). There was no significant difference between the two groups in the duration of renal-replacement therapy or the rate of recovery of kidney function or nonrenal organ failure. Hypotension during intermittent dialysis occurred in more patients randomly assigned to receive intensive therapy, although the frequency of hemodialysis sessions complicated by hypotension was similar in the two groups.

Conclusions: Intensive renal support in critically ill patients with acute kidney injury did not decrease mortality, improve recovery of kidney function, or reduce the rate of nonrenal organ failure as compared with less-intensive therapy involving a defined dose of intermittent hemodialysis three times per week and continuous renal-replacement therapy at 20 ml per kilogram per hour. (ClinicalTrials.gov number, NCT00076219.)

Figure 1

Enrollment, Randomization, and Follow-up of Study Patients.

Figure 2. Kaplan–Meier Plot of Cumulative Probabilities of Death (Panel A) and Odds Ratios for Death at 60 Days, According to Baseline Characteristics (Panel B)

Panel A shows the cumulative probability of death from any cause in the entire study cohort. Panel B shows odds ratios (and 95% confidence intervals [CI]) for death from any cause by 60 days in the group receiving the intensive treatment strategy as compared with the group receiving the less-intensive treatment strategy, as well as P values for the interaction between the treatment group and baseline characteristics. P values were calculated with the use of the Wald statistic. Higher Sequential Organ Failure Assessment (SOFA) scores indicate more severe organ dysfunction. There was no significant interaction between treatment and subgroup variables, as defined according to the prespecified threshold level of significance for interaction (P = 0.10). Sex was not recorded for one patient receiving lessintensive therapy.