Press Room: Press Releases

Fewer Transfusions After Study Publication

(DES PLAINES, Ill., February 3, 2005) - Canadian critical care physicians report a significant decrease in red blood cell transfusion thresholds and a significant increase in the use of single unit transfusions in the ICU during the last decade, according to an article in the January issue of Critical Care Medicine, the journal of the Society of Critical Care Medicine.

“Eighty-five percent of surveyed physicians said that they had modified their approach to transfusion, primarily in response to the publication of a major Canadian clinical trial and international guidelines,” says Paul C. Hébert, M.D., F.R.C.P.(C) M.H.Sc. (Epid), from the Centre for Transfusion and Clinical Epidemiology Program, Ottawa Health Research Institute in Ontario.

The researchers evaluated responses to a 2003 national survey of Canadian intensivists to determine red blood cell transfusion practice under the following four hypothetical scenarios: trauma, septic shock, stable gastrointestinal hemorrhage, and postoperative myocardial infarction.

“Transfusion thresholds differed significantly amongst the four scenarios,” the researchers report. “The proportion of respondents adopting a threshold of 70 g/L was 63% and 70% in the hypothetical scenarios of trauma and septic shock compared with 16% and 3% who adopted the same threshold for scenarios involving patients with stable gastrointestinal hemorrhage and postoperative myocardial infarct respectively. Fifteen percent of respondents identified transfusion thresholds exceeding 100 g/L for the postoperative MI scenario, and 7% identified this threshold for the gastrointestinal hemorrhage scenario. Only 0.4% of respondents adopted a 100g/L threshold for the two remaining scenarios. The reported use of single unit transfusions was 56% in 2002 versus 10% in 1993.”

The survey followed the 1993-94 national survey in which significant individual and regional variations in transfusion thresholds were observed. At that time, 40% of critical care physicians reported administering red blood cells at a threshold hemoglobin concentration of 100g/L and more than 90% of those surveyed administered two red blood cell units at a time.

The seminal study, “Transfusion Requirements in Critical Care,” which was published in the New England Journal of Medicine in 1999, impacted transfusion triggers. The randomized trial of 838 patients compared transfusion practices using a restrictive vs. a liberal strategy. The study found individuals do as well and perhaps better when they receive less transfused blood as opposed to more.

“Overall, we have documented a change in practice,” comments Dr. Hébert, who is a Career Scientist of the Ontario Ministry of Health. “Also, Canadian physicians still have difficulty in deciding how to treat patients with a heart attack. The physicians surveyed were less apt to adopt a restrictive approach to transfusion in that group of patients.”

Dr. Hebert and colleagues are repeating the same survey in the United States. “It will be interesting to see if the adoption is the same in the United States as in Canada,” he says.

Transfusion practices in Canada have changed rather substantially since the 1993 survey of transfusion practices. “We were pleased to observe that the results of our 1999 TRICC study had an impact on clinical practice,” says Dr. Hébert.

“There are still a number of studies yet to do,” he concludes. “There is only one trial of transfusion triggers of substance. There is need for further research on how best to administer red cells, because anemia and transfusions are both very common in critically ill patients”

Editorial: Transfusion Practice in the Critically Ill: Can we do better?

In an accompanying editorial, Howard L. Corwin, M.D., from the Dartmouth Hitchcock Medical Center, Dartmouth Medical School in Lebanon, N.H., discusses red blood cell transfusion practices and the challenges of incorporating trial results into clinical practice.

“While the change in practice observed by the Canadian intensivists is impressive, it stands in contrast to the current transfusion practice of intensivists in the both the United States and Europe,” comments Dr. Corwin. “ In both the CRIT and ABC trials the pre-transfusion hemoglobin level was approximately 8.5 g/dL, significantly higher than “best” practice as defined by the TRICC trial and current practice of Canadian intensivists. In fact in the CRIT study as many patients were transfused at hemoglobin levels above 9.0 g/dL as were transfused at hemoglobin levels less than 8.0 g/dL. The impressive adoption of the TRICC trial results by the Canadian intensivists, at least in part, reflects the fact the TRICC trial was performed in Canadian ICUs.”

“This raises the important question of how do we incorporate the results of randomized controlled trials, or best practice, into general practice,” he continues. “The dissemination of evidence-based innovations into practice is surprisingly difficult and involves overcoming both individual and institutional factors. This is true in the ICU, where there is clearly variation in adopting results of randomized trials as well as confusion among intensivists as to what interventions have in fact randomized controlled trial evidence available. As more and more of critical care practice is subjected to randomized controlled trials, the challenge for intensivists will be how to ensure that the results of these trials, both positive and negative, are incorporated into clinical practice.”

“Transfusion practices vary around the globe,” says Joseph E. Parrillo, M.D., editor-in-chief of Critical Care Medicine. “This type of research helps us understand the impact well-conducted research can make on patient care and clinical practice.”

Critical Care Medicine is the official journal of the Society of Critical Care Medicine. It is the premier peer-reviewed, scientific publication in critical care medicine. Each issue presents critical care practitioners with clinical breakthroughs that lead to better patient care, the latest news on promising research, and advances in equipment and techniques.

###

For more information, contact Elaine Salewske at (847) 827-7095 or esalewske@sccm.org.

The Society of Critical Care Medicine is the leading professional organization dedicated to ensuring excellence and consistency in the practice of critical care medicine. With nearly 13,000 members worldwide, the Society is the only professional organization devoted exclusively to the advancement of multiprofessional intensive care through excellence in patient care, professional education, public education, research and advocacy. Members of the Society include intensivists, critical care nurses, critical care pharmacists, clinical pharmacologists, respiratory care practitioners and other professionals with an interest in critical care, which may include physician assistants, social workers, dieticians, and members of the clergy.