Old blood as good as new, study says
Less time in storage doesn’t benefit transfusions, locally-led trial finds
When Garth Griffiths was in a coma with complications due to the H1N1 virus in 2009, it wasn’t known whether the blood he was receiving through a transfusion was as effective as it could be.
Now any doubts have been put to rest, says Dr. Dean Fergusson of the Ottawa Hospital Research Institute.
Fergusson has led an international trial, the results of which will be published Tuesday in the New England Journal of Medicine. He says it proves that blood that is as old as three weeks is just as effective for transfusions in critical-care patients as the freshly donated stuff.
Until this trial, that wasn’t an established fact.
Previous animal studies suggested fresh blood was better for patients — and conversely that blood stored for greater lengths of time was potentially harmful.
Just like any other biodegradable product, blood breaks down over time and is only good to use up to 42 days, which is partly what sparked the debate.
“The intuition was that if it breaks down too much it could be harmful or not as helpful at delivering oxygen to the tissues as fresher blood,” Fergusson said. “And so because of that building evidence from animals and these large sort of observational studies, there is pressure on the blood system to have more fresh blood available. And the immediate reaction is we need to evaluate it properly in a rigorous trial, and that is exactly what we did.”
Griffiths was fighting for his life when this study kicked off. He was in hospital in Ottawa in a coma due to complications from H1N1 that required multiple blood transfusions.
When the research team approached his parents to enrol him in the study, they consented.
“I woke up about three weeks later, and they came to me and explained the study that I was enrolled in and asked if I wanted to continue and I said absolutely,” said Griffiths, who has since fully recovered.
For the study, Fergusson collaborated with 64 research centres across Canada and Europe between 2009 and 2014. They compared mortality after 90 days in intensive-care patients who had been transfused with either fresh blood — stored an average of six days — or older blood, stored for an average of 22 days.
A total of 2,430 adults participated in the study, including 1,211 patients in the fresh-blood group and 1,219 in the older-blood group.
The mortality rates show that 37 per cent of the fresh-blood group and 35 per cent of the standard blood group had died after 90 days in a critical care situation that required a transfusion. In other words, there was no significant difference.
Fergusson said that before empirical data, there had been mounting pressure from the government and physicians to deliver more fresh blood.
“Some cardiac (surgeons) and anesthesiologists prefer giving fresher blood,” Fergusson said. “And we would call that into question as well. That it is probably not of benefit.”
Griffiths said he’s proud to be part of a study that will help ease the minds of patients around the world.
“It’s just one more piece of the puzzle that’s been solved in terms of best practice,” he said.