Patients in the emergency department are frequently given fluids through an IV as a treatment for a wide variety of injuries and medical complications. Historically, the most common fluid given to patients had been saline.  Saline contains a higher concentration of chloride than that of human blood, which could have negative effects on patients’ kidneys and blood vessels. Another type of fluid, called “balanced crystalloids”, has a chloride concentration more similar to that of human blood.  Whether using balanced crystalloids would result in better outcomes than using saline had been unknown.  Among approximately 13,000 patients receiving fluid in an emergency department prior to admission to the hospital, the  SALT-ED trial found using balanced crystalloids rather than saline did not increase the number of days alive outside the hospital but did decrease patients chances of dying, receiving dialysis, or having lasting kidney problems.  These findings suggest that balanced crystalloids should be used rather than saline for most patients receiving IV fluid in an emergency department.

Background: Comparative clinical effects of balanced crystalloids and saline are uncertain, particularly in noncritically ill patients cared for outside an intensive care unit (ICU).

Methods: We conducted a single-center, pragmatic, multiple-crossover trial comparing balanced crystalloids (lactated Ringer’s solution or Plasma-Lyte A) with saline among adults who were treated with intravenous crystalloids in the emergency department and were subsequently hospitalized outside an ICU. The type of crystalloid that was administered in the emergency department was assigned to each patient on the basis of calendar month, with the entire emergency department crossing over between balanced crystalloids and saline monthly during the 16-month trial. The primary outcome was hospital-free days (days alive after discharge before day 28). Secondary outcomes included major adverse kidney events within 30 days – a composite of death from any cause, new renal-replacement therapy, or persistent renal dysfunction (defined as an elevation of the creatinine level to ≥200% of baseline) – all censored at hospital discharge or 30 days, whichever occurred first.

Results: A total of 13,347 patients were enrolled, with a median crystalloid volume administered in the emergency department of 1079 ml and 88.3% of the patients exclusively receiving the assigned crystalloid. The number of hospital-free days did not differ between the balanced-crystalloids and saline groups (median, 25 days in each group; adjusted odds ratio with balanced crystalloids, 0.98; 95% confidence interval [CI], 0.92 to 1.04; P=0.41). Balanced crystalloids resulted in a lower incidence of major adverse kidney events within 30 days than saline (4.7% vs. 5.6%; adjusted odds ratio, 0.82; 95% CI, 0.70 to 0.95; P=0.01).

Conclusions: Among noncritically ill adults treated with intravenous fluids in the emergency department, there was no difference in hospital-free days between treatment with balanced crystalloids and treatment with saline. (Funded by the Vanderbilt Institute for Clinical and Translational Research and others; SALT-ED ClinicalTrials.gov number, NCT02614040 .).

Conflict of interest statement

Dr. Self reports receiving advisory board fees from Venaxis, Cempra Pharmaceuticals, Ferring Pharmaceuticals, and Biotest, consulting fees from Abbott Point of Care, and travel support from Gilead Sciences; and Dr. Rice, receiving consulting fees from Cumberland Pharmaceuticals and Avisa Pharma. No other potential conflict of interest relevant to this article was reported.

Manuscript Title: “Balanced Crystalloids versus Saline in Noncritically Ill Adults.”

Journal: New England Journal of Medicine

PMID: 29485926