Advanced Practice: Balanced Electrolyte Soluton vs Normal Saline in the Critically Ill


  • It is unknown whether resuscitation with normal saline (which has a higher concentration of sodium and chloride than plasma) or a balanced electrolyte solution (closer to physiologic plasma) such as lactated ringer's or Plasma-Lyte A is superior in the treatment of the critically ill

Study type

  • Cluster randomized controlled trial of balanced electrolyte solution versus normal saline


  • 15,802 patients from admitted to five ICUs at Vanderbilt Medical Center
  • ~15% of patients had a diagnosis of "sepsis" or "septic shock"
  • Median volumes of fluid administered within 30 days of ICU admission or until hospital discharge:
    • 1000 ml in balanced crystalloid group
    • 1020 ml in normal saline group




    • None of the three individual outcome measures met statistical significance, (though mortality and need for renal replacement therapy were very close)
    • The composite outcome (adding all three outcomes together) did reach statistical significance (p=0.04)
    • The possible purported mechanism for improved outcomes with balanced electrolyte solutions is not precisely known, but experts posit a reduction in hyperchloremic metabolic acidosis that may result from excessive normal saline resuscitation (and patients in the balanced electrolyte group did have a lower incidence of plasma bicarbonate levels <20 mmol/L)


    • Balanced electrolyte solutions such as Lactated Ringer's or Plasma-Lyte A should be considered as the resuscitation fluid of choice in the treatment of the critically ill


Semler MW, Wanderer JP, Ehrenfeld JM et al. Balanced Crystalloids versus Saline in Critically Ill Adults. NEJM 2018; 378(9):829-839.