Renal replacement therapy in the intensive care unit

SummaryRenal replacement can be defined as “An extracorporeal system or attachment to supplement, support or replace some or all functions of the kidney”. The kidney is uniquely sensitive, because of its microvasculature and permeability, to injury, either as a result of direct damage by toxins, oxygen free radicals or filtered inflammatory mediators, or microvascular failure in states of shock and sepsis. The resulting renal injury and failure is a particular problem in the Intensive Care setting, leading to a greatly increased mortality.This article explores the techniques available for renal replacement and support in the intensive care unit, discussing vascular access, choice of technique, choice of membrane, choice of dialysis buffer and strategies for maintaining circuit patency. It examines the techniques in common use in the United Kingdom and the outcome following renal replacement therapy, discussing some of the controversies surrounding renal replacement in terms of timing and dose. It also discusses some future development in technologies for renal replacement.