In the past, the solution to a blood shortage has been to put out the call for people to give more. But a Lawson Health Research Institute study points to a way of actually lowering demand.
Dr. Amit Garg, a scientist at Lawson and a nephrologist at London Health Sciences Centre (LHSC), says there a number of benefits from reducing the need for transfusions.
"If we don't need to give a blood transfusion we shouldn't, because transfusions have a risk of reactions and infection, they're a precious resource that we want to make sure we use it in the right people who benefit the most."
The clinical trial conducted by Garg and his colleagues took more than a decade, examining 4,531 participants across 73 centres in 19 countries, and the most significant findings just now being released.
The trial analyzed the impacts of two separate approaches to transfusions during cardiopulmonary surgeries.
Patients were randomized into two groups. One group received a restrictive approach, only receiving transfusion if their hemoglobin was below 7.5 grams per deciliter (g/dL).
The other received, what researchers called a more liberal approach. They received a transfusion if their hemoglobin was less than 9.5 g/dL. That guideline is regularly used in cardiac surgery today.
On average, participants in the restrictive transfusion group received 38 per cent fewer transfusions than those in the liberal group.
One of the most significant concerns during cardiopulmonary surgery is the potential for damage to the kidneys.
Both approaches were found to be equally safe, as the restrictive group did not have a higher rate of acute kidney injury. Risks were similar between participants with and without chronic kidney disease before surgery.
Garg says, "What the research shows is that it had no detriment on patient safety. And, particularly in this study, [for] the kidneys, which can frequently get injured in this procedure, the risk of that was no different."
And Garg also points to savings that could be achieved.
"There are health care costs to processing the blood, and preparing it, and delivering it. And so, by using 40 per cent less transfusions, we're having an impact on all those things. And yet we're not putting patients in any harm."
He says a new standard for transfusions during cardiopulmonary surgeries could have a substantial impact worldwide.
“With over 20 million cardiac surgeries performed worldwide each year - with it being one of the more common reasons for using blood in the hospital and an average of about three units of red blood cells used per patient - this suggests that approximately 20 million units of blood transfusions could be avoided each year without influencing the chance that a patient will develop post-operative kidney injury.”
The study, titled “Safety of a Restrictive versus Liberal Approach to Red Blood Cell Transfusion on the Outcome of AKI in Patients Undergoing Cardiac Surgery: A Randomized Clinical Trial,” is published in the Journal of the American Society of Nephrology.
