Findings from a new study on critically ill children may alter policies at hospitals where fresh red blood cell units are preferentially used.
A new study led by the Sainte-Justine University Hospital Centre and the University of Montreal, along with the Washington University School of Medicine in St. Louis, has found that transfusions using fresh red blood cell units—containing red cells that have spent seven days or less in storage—are no more beneficial than older red cell units in reducing the risk of organ failure or death in critically ill children. The results are published online today in the Journal of the American Medical Association.
Anemia is highly prevalent among children hospitalized in pediatric intensive care units. Transfusion with red blood cells is the only way to rapidly treat severe anemia that could be life-threatening. Red blood cells are stored in blood banks as units for up to 42 days. Some studies published over the past few decades have suggested that transfusion with units stored for longer periods might be less beneficial than transfusion with fresher units. The new findings should reassure patients, families and doctors: the current standard blood-bank practice of dispensing older cells is just as safe and effective for children in intensive care who are among the sickest and most fragile of patients.
The study, one of the largest clinical trials to investigate red blood cell storage for critically ill children, sheds light on a controversial aspect of transfusion medicine. The study was funded by the Canadian Institutes of Health Research (CIHR) in Canada, by the National Heart, Lung, and Blood Institute (NHLBI) in the U.S., by the Programme Hospitalier de Recherche Clinique (PHRC) in France and by the Quebec Ministry of Health.
The study was led by two principal investigators: Dr. Marisa Tucci of Sainte-Justine and Dr. Philip Spinella of Washington University; both are pediatric intensivists and researchers. According to the investigators, the findings indicate that doctors who care for children in pediatric critical care units should not be afraid to use older red cells in their patients. The results from this study suggest that those who systematically request fresh red cells should consider discontinuing this practice unless there are extenuating circumstances. The findings also provide good news for blood banks, who will likely feel less pressure to respond to requests for fresh red cells.
Standard practice to avoid wastage
Red blood-cell transfusions are commonly administered in critically ill children who have illnesses that increase the need for transfusion, such as trauma, cancer chemotherapy, major surgery with significant intraoperative bleeding, and conditions such as sickle cell disease and thalassemia. Transfusing the oldest red blood cells in the stored inventory first is standard practice among many hospitals to avoid wastage. However, some hospitals preferentially give fresh red blood cells to critically ill children, even though clinical studies supporting the benefits of this practice have been lacking.
To help fill the research gap, the investigators of the 'Age of Blood in Children in Pediatric Intensive Care Units' (ABC-PICU) study undertook a randomized trial that recruited patients admitted to pediatric intensive care units in 50 medical centres. The study began in February 2014 and ended in November 2018.
In all, 1,461 children ranging in age from 3 days to 16 years who were admitted to pediatric intensive care units were recruited in the United States (29 sites), Canada (10 sites), France (8 sites), Italy (2 sites), and Israel (1 site); Sainte-Justine University Hospital was the coordinating centre in Canada and recruited the greatest number of patients (over 160). Data management and analysis was done by Dr. Dean Fergusson of the Centre for Practice-Changing Research at the University of Ottawa, in coordination with Drs. Tucci and Spinella.
No reduction in organ dysfunction
In the study, half of the patients received transfusions with fresh red blood cells stored for seven days or less and half received transfusions with older cells. The primary outcome measured was the development of new or progressive multiple organ dysfunction (impairment of one or more organs).
The researchers found that fresh cells did not reduce the incidence of new or progressive multiple organ dysfunction or death compared to older cells and that the outcomes were not significantly different between the two groups. About 20.2 per cent of those who received fresh red cells experienced new or progressive organ dysfunction while 18.2 per cent of those who received older cells experienced similar dysfunction.
The relatively large number of patients recruited and their geographic diversity, as well as the inclusion of a wide variety of patients, were among the study's strengths, making it reasonable for researchers to generalize the findings to a larger pediatric population.
The researchers did note some caveats, however. The study did not examine whether the use of the oldest red blood cells allowable (more than 35 days) affects outcomes, or whether fresh cells affect outcomes for children requiring large-volume transfusions. The children in this study received low-volume red blood cell transfusions.
The results of this study are applicable to the vast majority of children in pediatric intensive care units and show that current red blood cell transfusion practices are safe.
About this study
"Effect of fresh vs. standard-issue red blood cell transfusions on multiple organ dysfunction syndrome in critically ill pediatric patients", by Dr. Marisa Tucci et al, was published Dec. 10, 2019 in the Journal of the American Medical Association.
About the CHU Sainte-Justine Research Centre
CHU Sainte-Justine Research Centre is a leading mother-child research institution affiliated with Université de Montréal. It brings together more than 200 research investigators, including over 90 clinicians, as well as 350 graduate and post-graduate students focused on finding innovative means of prevention, faster and less invasive treatments, and personalized approaches to medicine. The Centre is part of CHU Sainte-Justine, which is the largest mother-child hospital in Canada and second most important pediatric hospital in North America.