A more liberal approach to blood transfusions would allow people hospitalized in an intensive care unit to regain more functional independence and a better quality of life after serious craniocerebral trauma, indicates a study led by a researcher at the University Hospital of Quebec.

Six months after their accident, patients who had benefited from this liberal approach enjoyed greater functional independence – for example, their ability to feed themselves or dress themselves – and a better quality of life than those subjected to to a more restrictive approach. However, the incidence of death and major disability did not differ significantly between the two groups.

A study published in 1999 led doctors to reduce their use of blood products and to tolerate higher levels of anemia than before, recalled Dr. Alexis Turgeon, who is also a professor at Laval University and holder of the Canada Research Chair in Neurological Intensive Care and Traumatology.

“The problem is there are specific patient populations or clinical conditions that don’t really lend themselves to having restrictive thresholds,” he said. Or at least, for several years we have been wondering if we are harming certain populations, and in particular patients who have craniocerebral trauma. »

In 2017, Dr. Turgeon and his colleagues launched a randomized clinical trial involving 742 people hospitalized in an intensive care unit in 34 hospitals in Canada, the United Kingdom, France and Brazil. All subjects had suffered a moderate or severe TBI and suffered from anemia.

The researchers wanted to compare two blood transfusion strategies – one called restrictive and the other liberal – to manage these patients.

The restrictive approach tolerates a low hemoglobin concentration before giving a transfusion, while the liberal approach aims to maintain high hemoglobin concentrations, therefore giving more blood transfusions.

Hemoglobin is what allows red blood cells to carry oxygen to the organs. Most patients hospitalized following a TBI have anemia, which could reduce oxygen transport to the brain at a time when it is very vulnerable and disorganized.

The heart responds to anemia by speeding up the pace to ensure that enough oxygen gets to the organs. The brain, however, has its own independent strategy, explained Dr. Turgeon.

“The brain does not tolerate a lack of oxygen, and in a context of anemia, it does not function like the rest of the body,” he recalled. It has its own self-regulatory mechanism and it does not respond to increased heart rate. »

If the heart rate increases, he added, the brain sets up mechanisms to protect itself. Faced with a drop in hemoglobin, for example, it will increase its blood flow to ensure that it receives enough oxygen.

But during head trauma, said Dr. Turgeon, these mechanisms are disrupted and no longer function adequately.

“The brain has an inability to increase cerebral blood flow adequately,” he explained. If blood flow is not able to increase, there is a real reduction in oxygen transport to the brain. »

The hypothesis behind this clinical trial therefore assumed that it might be beneficial for these patients to return to the more liberal blood transfusion strategies that were prevalent in the 1990s, i.e. transfusing as soon as the hemoglobin concentration reached 10 grams/deciliter, rather than expecting 7 grams/deciliter as the new standards indicate.

If blood flow is impaired, and if we are not able to compensate for the anemia, we should be able to ensure adequate oxygen transport by increasing the number of available red blood cells, summarized Dr. Turgeon. .

“In brain trauma, it is not mortality that is most important,” said Dr. Turgeon. Yes, families want to know if the patient will survive, but if they do, what condition will they be in? »

The researchers therefore measured the impact of the more liberal strategy on different patient-centered outcomes. If the main analysis is not “statistically significant,” said the researcher, “the main clinical outcomes show a reduction in major disabilities at six months with a liberal strategy compared to the restrictive strategy.”

These results are all the more interesting as it is not a question of a new experimental drug or sophisticated technologies, but of a very simple strategy which can be implemented anywhere in the mode, recalled Doctor Turgeon.

This is also the first intervention to show an improvement in clinical outcomes in such a situation, he recalled.

“Our arsenal of interventions is extremely limited and is aimed much more at preventing secondary brain damage than anything else,” said Dr. Turgeon. We see brain trauma as a unique event, but we know that in the first days there are areas of darkness. So probably (with our intervention) we protect the tissue which is very sick from deteriorating even more. »

The results of this study were published by the New England Journal of Medicine, which is possibly the most influential medical publication on the planet. Doctor Turgeon also had the opportunity to present them as part of the Critical Care Reviews Meeting, a prestigious international meeting intended for intensive care.

Now that the results have been released publicly, it’s up to the medical community to decide how they will be used, Dr. Turgeon said, but “these are clearly results that are going to lead to changes in practice.”

“Personally, on Monday when I return to the unit, it is certain that I will transfuse my patients who have moderate or severe head trauma at much higher thresholds than what I did before,” he said. concluded.