Renal failure and its treatment

Renal impairment is common, carries high morbidity and mortality, but may be difficult to define accurately. This article begins with a description of normal renal physiology and outlines methods for assessing renal function both by the bedside and in the laboratory. Causes of renal failure are classified, and a thorough explanation of the complex pathophysiology of renal impairment in association with multiple organ dysfunction syndromes is given. Guidelines are presented on management of the patient with renal dysfunction in the intensive care setting, covering evaluation, resuscitation, inotropic support and drug therapy. Mechanisms of renal replacement therapy are described and explained, including haemofiltration and haemo- and peritoneal dialysis. The article ends with a comprehensive section on anaesthesia for patients with renal disease, including preoperative assessment, perioperative management and techniques for postoperative analgesia.