Initiation Strategies for Renal-Replacement Therapy

Posted by • July 14th, 2016

2016-07-08_11-02-36Renal-replacement therapy is the cornerstone of the management of severe acute kidney injury. Gaudry et al. compared a strategy of early initiation of renal-replacement therapy with a strategy of delayed initiation in patients in the intensive care unit who had acute kidney injury of Kidney Disease: Improving Global Outcomes (KDIGO) classification stage 3.

This multicenter randomized trial compared strategies of early and delayed renal-replacement therapy in patients with severe acute kidney injury. There was no significant difference in mortality, the primary outcome, between the study groups. A new Original Article summarizes.

Clinical Pearl

• What evidence is available from randomized trials regarding the optimal timing for the initiation of renal-replacement therapy in critically ill patients with severe acute kidney injury?

Many studies have focused on methods of renal-replacement therapy, but the issue of when to initiate the therapy in the absence of a potentially life-threatening complication directly related to renal failure remains a subject of debate. The available knowledge about the initiation of renal-replacement therapy during acute kidney injury derives predominantly from observational studies. Indirect evidence has suggested that early renal-replacement therapy could confer a survival benefit. However, two observational studies reported high survival rates among patients who did not receive renal-replacement therapy, and one study reported adverse outcomes in association with very early renal-replacement therapy in patients with sepsis.

Clinical Pearl

• What potential advantages do early initiation and delayed initiation of renal-replacement therapy each offer?

Early initiation of renal-replacement therapy may allow for better control of fluid and electrolyte status, removal of uremic toxins, and prevention of complications such as gastric hemorrhage and metabolic encephalopathy. Delaying renal-replacement therapy initiation is intuitively unlikely to have any immediate benefit per se. However, a delay may allow time for the stabilization of a patient’s condition before renal-replacement therapy is initiated and may avoid the need for such support, which is not devoid of risk.

Morning Report Questions

Q: Is there a survival or other benefit associated with a delayed strategy of renal-replacement therapy in critically ill patients with severe acute kidney injury? 

A: In the study by Gaudry et al., contrary to the authors’ hypothesis, no survival benefit was observed with the delayed strategy of renal-replacement therapy. Mortality did not differ significantly between the two study groups: 48.5% (95% CI, 42.6 to 53.8) in the early-strategy group and 49.7% (95% CI, 43.8 to 55.0) in the delayed-strategy group (P=0.79). In this trial, however, a strategy of delayed initiation of renal-replacement therapy in critically ill patients with severe acute kidney injury obviated the need for renal-replacement therapy in almost 50% of cases (resulting in a considerable difference in the total number of renal-replacement therapy sessions). The lengths of stay in the intensive care unit and in the hospital were similar in the two groups, which indicates that allowing time for renal function recovery did not lead to prolongation of the stay in the intensive care unit.

Q: Do the results of the study by Gaudry et al. suggest that a “wait and see” approach should be favored for all critically ill patients with severe acute kidney injury?

A: The authors of the Gaudry study state that their study should not be interpreted as suggesting that a “wait and see” approach is safe for all patients. Indeed, careful surveillance is mandatory when deciding to delay renal-replacement therapy in patients with severe acute kidney injury so that any complication will be detected and renal-replacement therapy initiated without delay.

Figure 1. Probability of Survival and Timing of Renal-Replacement Therapy.

Table 2.  Primary and Secondary Outcomes and Adverse Events.

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