Fluid administration and the kidney.

PURPOSE OF REVIEW: Intravenous fluids are widely administered in the ICU with the intention of preventing or ameliorating acute kidney injury (AKI). This review focuses on recent studies examining fluid administration and renal function in critical illness to critically examine conventional justifications for fluid administration. RECENT
FINDINGS: Early, targeted, resuscitation of inadequate cardiac output in shock may have a beneficial effect on organ function and patient outcome. However, experimental evidence suggests the relationship between fluid administration and an increase in renal oxygen delivery is weak, whereas any beneficial effects from fluid administration can be short lived. Conversely, evidence associating fluid overload and adverse outcomes is strengthening, whereas more restrictive fluid administration does not seem to predispose to clinically significant AKI in many situations. Furthermore, concerns persist that some colloid or high chloride concentration solutions may directly impair renal function independent of volume overload.
SUMMARY: Adequate volume resuscitation remains a cornerstone to the emergent treatment of critical illness. However, continued fluid administration and positive fluid balances have not been shown to improve renal outcomes and may worsen overall prognosis in AKI. Concerns about renal dysfunction should not deter clinicians from adopting more restrictive approaches to fluid administration.