SLEDD and Hybrid Renal Replacement Therapies for Acute Renal Failure in the ICU

Abstract

Acute renal failure with need for renal replacement therapy in the intensive care unit (ICU) is a complex and devastating condition, with a reported mortality rate as high as 50–80% [1, 2]. Although gross mortality rates have only declined slightly over the past decades, it is accepted that survival has enhanced by improvement in overall care, since the comorbidity of patients and the severity of the diseases treated has also increased dramatically [3]. Although acute renal failure by itself contributes to the overall mortality of critically ill patients, it is important to understand that acute renal failure mostly develops as a consequence of other underlying comorbidities, and that patients often do not die of their acute renal failure but from these underlying conditions. Thus, the idea that by inventing ‘the perfect renal replacement therapy-machine’, no more patients with ICU-related acute renal failure will die, will remain an illusion. Furthermore, acute renal failure mostly recovers if the patient survives. Renal replacement therapy in acute renal failure should thus be seen as a bridging therapy that allows the patient to survive while the native kidneys recover. The main objective of renal replacement therapy should, thus, be to avoid additional harm to the patient as much as possible while clearing the uremic waste products and maintaining the ‘milieu interieur’ as closely possible to normal.