[Diuretics for acute kidney injury. Is there a rationale for their administration?].

Acute kidney injury (AKI) is a frequent and severe disorder that is observed in a variety of clinical settings. Early recognition of this syndrome is of critical importance in order to prevent progression to more severe forms, which are associated with a higher risk of complications and death. Efforts to prevent AKI have been made through a variety of interventions and drugs. However, no benefit has been demonstrated to date except for volume expansion and avoidance of nephrotoxic drugs. Diuretics have been extensively studied because of their main pharmacokinetic actions: reduction of renal vascular resistance and inhibition of active transport in the thick ascending limb, which reduces the energy requirement and eventually protects cells under ischemic conditions. Loop diuretics such as furosemide have been extensively tested to prevent AKI as well as to treat established AKI. Although experimental trials demonstrated that the administration of furosemide prevents the onset of AKI, no clinical trial has been able to reproduce this beneficial effect in humans. Moreover, there is evidence of impairment of renal function associated with it use. Like loop diuretics, mannitol induces diuresis in patients at risk of AKI but does not reduce its incidence. Recently, studies have demonstrated that natriuretic peptides such as h-ANP and nesiritide were associated with a reduction of the incidence of AKI in cardiac surgery patients. These promising results need to be confirmed in larger studies.