[Acute renal failure and sepsis : Just an organ dysfunction due to septic multiorgan failure?]

Acute renal failure (ARF) is clinically defined as an abrupt, but in principle reversible deterioration of glomerular and tubular function. Regarding pathophysiology, ARF is caused by ischemic renal conditions and toxic mediators. Sepsis is the most common cause of ARF in the intensive care unit and ARF is an independent risk factor for lethality of septic patients. Interventions to protect the kidneys against ARF include preliminary optimization of renal perfusion by volume load with cristalloid solutions and the administration of vasopressors. Daily maximum permissible dosages for colloids should not be exceeded and hyperoncotic colloid solutions should be generally avoided. Dopamine in "renal dosage" is nowadays obsolete. Loop diuretics produce diuresis and can be beneficial to extrarenal organs by improving fluid homeostasis, however diuretics do not improve kidney function and outcome. Therefore, diuretics are not indicated for patients with imminent or existing ARF. Septic patients with ARF can be treated by intermittent and continuous forms of renal replacement therapy, whereas continuous convective and intermittent diffusive methods are equivalent when utilizing an ultrafiltration rate > or =20 ml/h*kg body weight or a therapeutic interval > or =3 times/week.