Renal protection in a surgical intensive care unit

Perioperative renal dysfunction is an important cause of morbidity and mortality. With increase of life expectancy, older patients with more co-morbidity are being submitted to high risk surgical procedures, what make clinical practice related to organ protection possible modifier of short and long term survival. This review about renal protection in surgical intensive care unit points risk factors and discusses scientific evidence related to reduction of renal dysfunction in perioperative. Although low extraction and adequate renal reserve of oxygen, the kidney is extremely sensible to hypoperfusion being renal acute insufficiency a frequent complication of hemodynamic instability. This apparent paradox, high oxygen content and reduced extraction with high incidence of renal damage to hypotension reflects the intra-renal gradient of oxygen, what makes renal medulla highly susceptible to ischemia. Factors associated with renal lesion are observed in all fases of perioperative period: fasting, contrast use, hypovolemia, hypotension, catecholamine and cytokine release, extracorporeal circulation, trauma, rabdomiolisys and aortic clamp. Management of renal damage is based in principals of perioperative renal physiology and glomerular hemodynamic. Clinical practice directed to organic protection should be implemented to minimize the impact this dysfunction.