R E V I E W Renal replacement therapy in the intensive care unit Neesh Pannu1 RT Noel Gibney2 1Divisions of Nephrology and Critical Care Medicine, 2Division of Critical Care Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada Correspondence: Neesh Pannu Faculty of Medicine and Dentistry, University of Alberta, 11-107 CSB, 8440 –112 St Edmonton, AB Canada T6G 2G3 Tel +1 780 407 3627 Fax +1 780 407 7878 Email npannu@ualberta.ca Abstract: Acute renal failure is a common complication in the intensive care unit (ICU). Over the last 25 years, there have been significant technological advances in the delivery of renal replacement therapy, particularly as it pertains to the critically ill patient population. Despite these advances, acute renal failure in critically ill patients continues to carry a poor prognosis. In this article, we review the current literature about timing and initiation of renal replacement therapy in the ICU as well as practical considerations regarding the prescription and delivery of dialysis. Keywords: acute renal failure, dialysis, continuous renal replacement therapies (CRRT) Introduction Acute dialysis-dependent renal failure is a common problem in the intensive care unit (ICU) and, despite significant improvements in the care of critically ill patients, the mortality from this complication remains over 50%. The development of renal failure is an independent predictor of mortality in this patient population (Levy et al 1996; Metnitz et al 2002). Over the last two decades there has been an evolution in the field of hemodialysis and consequently our approach to the treatment of acute renal failure (ARF). The use of new devices and techniques has allowed us to achieve better-tolerated and more efficient renal replacement therapy. In this article, we review the current literature about renal replacement therapies, with a focus on continuous therapies and how they may be used in the ICU. What are the indications for renal replacement therapy in patients with acute renal failure? A patient with ARF requires renal replacement therapy (RRT) when he or she has an acute fall in glomerular filtration rate and has developed, or is at risk of developing clinically significant solute imbalance/toxicity or volume overload. The precise timing of RRT initiation is usually a matter of clinical judgment. The classic indications for dialysis include: 1. diuretic resistant pulmonary edema 2. hyperkalemia (refractory to medical therapy) 3. metabolic acidosis (refractory to medical therapy) 4. uremic complications (pericarditis, encephalopathy, bleeding) 5. dialyzable intoxications (eg, lithium, toxic alcohols, and salicylates). While many of these indications are typically used in the setting of chronic renal failure, the consequences of these complications are likely to be more severe in critically ill patients; therefore, there has been a growing trend to start dialysis prior to the development of these indications. Delays in the initiation of treatment have Therapeutics and Clinical Risk Management 2005:1(2) 141– 150 © 2005 Dove Medical Press Limited. All rights reserved 141