Renal Replacement Therapy

Abstract

Acute renal failure (ARF) is a commonly anticipated diagnosis in critically ill patients in the intensive care unit (ICU). Its actual frequency varies from less than 10% to approximately 25% in different series including different patient demographics and definitions of ARF.1, 2, 3, 4, 5 The elevations in serum creatinine and urea nitrogen concentrations observed in a majority of these patients (more than 90%) are caused by renal hypoperfusion and related parenchymal dysfunction, the latter referred to as acute tubular necrosis (ATN)3,6 (Tables 33.1, 33.2). Between one-third and one-half of the observed ATN occurs during infection/sepsis, with the rest related to medical-surgical conditions, including hypotension and toxin exposure.3,6 ARF is typically accompanied by a number of comorbidities [i.e., respiratory failure (67%), heart failure (48%), and liver failure (31%)].7 In many series, more than one-half of the patients who develop ARF in the ICU require some form of renal replacement therapy (RRT).3,6,7