SALT-ED (2018)

The optimal type of intravenous fluid for non-critically ill patients in the emergency department (ED) was unclear, with concerns about normal saline's potential to cause hyperchloremic metabolic acidosis and acute kidney injury. This study aimed to compare the effects of balanced crystalloids versus normal saline on major adverse kidney events in this population.

This was a pragmatic, cluster-randomized, multiple-crossover trial conducted in the ED, enrolling non-critically ill adults requiring intravenous fluids. Patients received either balanced crystalloids (Lactated Ringer's or Plasma-Lyte A) or 0.9% normal saline, with the primary endpoint being major adverse kidney events within 30 days (MAKE30), defined as death from any cause, new renal replacement therapy, or persistent renal dysfunction.

Among 13,347 patients, the incidence of MAKE30 was significantly lower in the balanced crystalloid group compared to the normal saline group (4.7% vs. 5.6%; adjusted odds ratio, 0.82; 95% CI, 0.70 to 0.96; P=0.01). This difference was driven primarily by a reduction in new renal replacement therapy and persistent renal dysfunction, with no significant difference in mortality. Subgroup analysis suggested a greater benefit in patients with baseline chronic kidney disease.

For non-critically ill patients in the ED, balanced crystalloids are superior to normal saline in reducing major adverse kidney events.

This study was unblinded, which could introduce bias, and the pragmatic design allowed for clinician discretion in fluid choice after randomization. The generalizability to all ED populations or specific critical illness etiologies may be limited.