Resuscitation fluids and hyperchloraemic metabolic acidosis

Abstract

Until recently, saline and Hartmann’s solution were used almost interchangeably, while interest in colloids was mainly focused on the colloid component (gelatin, dextran or starch) rather than the carrier solution. Some clinicians are still not aware that almost all colloids are suspended in saline. There are no studies examining clinical outcomes after trauma or ICU resuscitation that compare saline-based fluids with ‘balanced’ fluids such as Hartmann’s solution. Recent evidence from volunteer and surgical studies suggest that the use of saline-based fluids (both the crystalloid saline and when used as a carrier solution for a colloid) can cause a hyperchloraemic metabolic acidosis. Although this may not be directly harmful, it may result in incorrect treatment of the acidosis such as more saline-based fluid. Increasing awareness of the ‘Stewart hypothesis’ has led to new ways of managing acid-base balance.