Fluid Overload in Critically Ill Patients with Acute Kidney Injury

Fluid overload may occur in critically ill patients as a result of aggressive resuscitation therapies. In such circumstances, persistent fluid overload must be avoided since it does not benefit the patient while it may be harmful. In the septic patient, early volume expansion seems to be beneficial. Beyond that threshold, when organ failure develops, fluid overload has been shown to be associated with worse outcomes in multiple disparate studies. One well-designed randomized controlled trial showed the benefit of a conservative fluid management strategy based on limited fluid intake and use of furosemide in such patients. Use of diuretics should be only short term as long as it is effective, generally at high doses, while avoiding simultaneous utilization of nephrotoxins such as aminoglycosides. Multiple randomized controlled trials have not shown benefit in the use of diuretics, either to prevent AKI or to treat established AKI. If fluid overload (defined as fluid accumulation >10% over baseline) develops and the patient does not respond to diuretics, persistent use of these drugs will only lead to a delay in the initiation of dialysis or ultrafiltration and an increased risk of negative patient outcomes. In that setting, early initiation of continuous renal replacement therapies may be preferable.