Blood transfusions save lives. If you need one, there's no question you should get one. But a lot of patients who get transfusions probably don't need them.
Doctors now say they get better results by using donor blood less often in patients who are medically stable. There's growing consensus that transfusions can increase the risk of infection and do more harm than good.
It's a big change in how some physicians practice medicine and it's led to some Minnesota hospitals tightening their transfusion guidelines.
"I was told in medical school, 'don't bother giving one unit, you should just give two if you're going to give any,'" said Allina Health System anesthesiologist Josh Martini. Today, he said, the mantra is changing to "why give two, when one will do?"
Allina tightened its transfusion guidelines in 2012. The average number of blood units transfused to patients in the health system has dropped by 38 percent.
When the system unveiled its new guidelines, the transfusion team wanted the message to be memorable, like a popular television show you just can't miss. So they took inspiration from "Law & Order" TV show and recorded a DVD parody called "The Blood Police."
In the episode, called "The Case of Too Much Blood," a doctor (Martini, the anesthesiologist) and nurse decide that a patient, who has just had knee surgery, needs donor blood based on her low hemoglobin reading. Hemoglobin levels reflect the oxygen-carrying capacity of a patient's blood.
As they walk toward the patient's room, an officer with the Blood Police, who looks a bit like actor Kevin Spacey, pulls the doctor and nurse aside and grills them about their plan to give the patient two units of red blood cells.
In keeping with the Law & Order vibe, the blood cop doesn't show much mercy when he hears that the doctor and nurse ordered the blood based on the patient's test result alone, rather than an in-person assessment of her condition.
"This has been in the refrigerator for 21 days," the pretend cop growls. "Do you know what a red blood cell looks like after 21 days in the refrigerator?"
Researchers say donated red cells are a poor substitute for a patient's own blood. Yes, the cells save lives when patients suffer heavy bleeding. But up to 25 percent of red blood cells are dead by the time they're transfused into patients. The body recognizes those dead cell fragments and orders the immune system to clean them up, making the body less able to fight infections.
A similar, if less cinematic, effort at Regions Hospital in St. Paul has also reduced transfusions. Two years ago 20 percent of joint surgery patients at Regions received donor blood. Now just 5 percent get a transfusion. The hospital cut its blood costs by $229,000 in that span.
More importantly, the hospital's infection rate dropped during the same time period. That's probably not a coincidence, said orthopedic surgeon Gavin Pittman. Doctors, he added, have data showing patients are spending less time in the hospital and suffering fewer medical complications such as pneumonias or congestive heart failure.
The new thinking on transfusions has the added benefit of conserving the blood supply, which is a limited resource. That's prompted some health systems to look at what else they can do to save blood.
Mayo Clinic in Rochester transfuses more blood each year than some western states. When it discovered that it was discarding a lot of blood because the portable coolers in its operating rooms could only chill blood packets effectively for about four hours, Mayo installed new coolers that stay cold for 18 hours. That's long enough to get through most surgeries, said surgeon Robert Cima.
"We were 'wasting' because we weren't using it, almost $500,000 to $600,000 a year of blood," Cima said. "That has gone down to almost zero."
There are signs that new transfusion limits and blood conservation efforts may be relieving pressure on the nation's blood supply. Red cell transfusions have fallen by about 8 percent since 2008, according to AABB, formerly known as the American Association of Blood Banks, nearly matching the decline in blood donations.
It's not known how many Minnesota hospitals have launched projects to reduce blood transfusions. The American Red Cross - North Central Region says it's collaborating with several large hospitals in the metro area and a few smaller ones in greater Minnesota.
The science supporting a more conservative transfusion approach has been around for more than a decade, but the message is still new to many, said David Mair, medical director for the regional Red Cross.
"We've kind of been flying this banner for years," said Mair. "But in the past few years we've really seen a dramatic change" across the country, he added.