Saline solution has been part of standard hospital treatment for 150 years.
It’s the bag of saltwater that hangs above many patients. It is administered intravenously to make sure patients don’t get dehydrated and their blood pressure remains strong. It is also used to administer drugs and nutrition if a patient can’t eat.
But new research finds it might also kill you.
Two separate studies looked at saline use in 15,000 ICU and 13,000 ER patients. The research was conducted by Vanderbilt University Medical Center. It was published recently in The New England Journal of Medicine.
The findings showed that saline can harm kidneys. And it doesn’t work well for fluid replacement.
An alternative to saline solution was found to be safer and to work better. It’s something called balanced fluids. They are sometimes also called crystalloid fluids.1
Balanced fluids have salt in them, just like saline solution. But they also contain potassium and other electrolytes. This makes it more like plasma, the clear part of your blood. Balanced fluids have become standard treatment in Europe and Australia.
The Vanderbilt research found that for every 100 people on balanced fluids, there was one fewer death or severe kidney problem. 2 3 4
That may not seem like much. But Dr. Matthew Semler, who led the research points out that if U.S. hospitals switched to balanced fluids, “tens or hundreds of thousands of patients would be spared death or severe kidney problems.”
Researchers estimate the difference could mean 50,000 to 70,000 fewer deaths a year. And there would be 100,000 fewer cases of kidney failure.
The problem with saline has to do with the amount of salt in it. The 0.9% sodium chloride concentration it contains is higher than the natural salinity of human blood. This makes kidneys work harder. Balanced solutions provide a closer match to what’s in your blood.
Critical care specialist Dr. Timothy Buchman was not involved in the study. But he says the switch to balanced fluids is long overdue.
“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,” he said.
Some hospitals have made the switch. But most still use saline. The reason for the lag is not price. Both saline and balanced fluids cost about the same, just a dollar or two per IV. And many suppliers make both types. So switching should not be difficult.
Just Say ‘No’ to Saline
So why are hospitals still using saline?
Historically, saline has been the most widely used IV fluid. That’s what doctors are taught to use in medical school. So that’s what many of them are most comfortable with.
The only advantage saline has is that it is more compatible with blood transfusions than balanced solutions. But these days blood transfusions are relatively rare.
If you are going to the hospital for a procedure, ask your doctor if you’ll be getting IV fluids. If so, be sure to ask for balanced fluids. It’s the safer solution.