Perioperative fluid management: moving toward more answers than questions-a commentary on the RELIEF study.

Perioperative fluid and hemodynamic management have been much-debated topics over the last few years. Recently, a number of large trials have been published to help inform this debate. The Restrictive versus Liberal Fluid Therapy for Major Abdominal Surgery (RELIEF) study is the largest trial to date of perioperative fluid management. The 3000-patient trial comparing 2 different fluid regimes showed that a restrictive fluid regimen during and up to 24 h after surgery was associated with an increase in acute kidney injury (AKI). This result is at odds with a recent trend to a more restrictive fluid approach during major surgery and suggests that practice may have become too restrictive. A moderately liberal (aiming for 1-2 l positive) or goal-directed approach is therefore recommended.