Balanced fluids, rather than saline, recommended for IVs

Feb. 28 (UPI) -- Researchers at Vanderbilt University have a recommendation to medical providers: Don't use saline in intravenous bags.

Vanderbilt researchers found that patients are better off if given balanced fluids that closely resemble the liquid part of blood, rather than saline. The findings are based on companion landmark studies published Tuesday in the New England Journal of Medicine.

Dr. Matthew W. Semler of Vanderbilt University Medical Center in Nashville also presented the findings this week at the Society of Critical Care Medicine annual meeting.

"Our results suggest that using primarily balanced fluids should prevent death or severe kidney dysfunction for hundreds of Vanderbilt patients and tens of thousands of patients across the country each year," Semler said in a press release.

"Because balanced fluids and saline are similar in cost, the finding of better patient outcomes with balanced fluids in two large trials has prompted a change in practice at Vanderbilt toward using primarily balanced fluids for intravenous fluid therapy."

The researchers examined 15,802 intensive care patients in one trial and 13,347 emergency department patients in another trial. They were assigned to receive saline or balanced fluids if they required intravenous fluid between June 2015 and April 2017.

Serious kidney problems or death occurred 1 percent less often in the balanced fluids group compared with the saline group, according to the studies.

"The difference, while small for individual patients, is significant on a population level," said study author Dr. Wesley Self, an associate professor of Emergency Medicine. "When we say a 1 percent reduction, that means thousands and thousands of patients would be better off."

Switching from saline to balanced fluids could lead to more than 100,000 fewer patients experiencing kidney damage or dying every year in the United States, the researchers estimate.

In the surgery study, 14.3 percent of the patients treated with a balanced crystalloid solution experienced a major adverse kidney event compared with 15.4 percent of patients given saline intravenous fluids. In-hospital deaths at 30 days was 10.3 percent in the balanced-crystalloids group and 11.1 percent in the saline group

In a second trial, the number of hospital-free days was similar between the two groups. But use of balanced crystalloids resulted in a lower incidence of major adverse kidney events within 30 days -- 4.7 percent, compared to 5.6 percent in the saline group.

"Doctors have been giving patients IV fluids for more than 100 years and saline has been the most common fluid patients have been getting," said study author Dr. Todd Rice, an associate professor of Medicine.

"With the number of patients treated at Vanderbilt every year, the use of balanced fluids in patients could result in hundreds or even thousands of fewer patients in our community dying or developing kidney failure," they said. "After these results became available, medical care at Vanderbilt changed so that doctors now preferentially use balanced fluids."

Semler told Medpage Today that doctors prefer saline based on experience.

"The choice about which one to use mostly comes down to how physicians are trained," he said. "Internal medicine physicians tend to use saline while anesthesiologists and surgeons tend to use balanced fluids more."

Critical care specialist Dr. Timothy Buchman, of Emory Healthcare in Atlanta, who was not involved with the study, expects more doctors to switch to fluids.

"After roughly 75 years of intravenous medicine and 50 years of advanced trauma life support, we are finally recognizing that maybe what we should be giving is what the patient has been losing," Buchman said.