December 5, 2019

Background: Saline (0.9% sodium chloride) has historically been one of the most common intravenous fluids administered in critically ill adults.  However, the supraphysiologic chloride concentration can cause hyperchloremia, metabolic acidosis, renal vasoconstriction and alter immune function.  There is nothing normal about normal saline. Balanced crystalloids (i.e. lactated Ringer’s solution, Plasma-Lyte A, etc) contain electrolyte compositions that are closer to physiologic levels.  Recently, the Isotonic Solutions and Major Adverse Renal Events Trial (SMART) [2] compared balanced crystalloids to saline among critically ill adults and found that balanced crystalloids decreased the composite outcome of death, new renal replacement therapy, or persistent renal dysfunction (This composite outcome was primarily driven by mortality benefit).  Interestingly, in the subgroup analyses of septic patients, balanced crystalloids seemed to have its biggest benefit in MAKE30 compared to saline.