Blood transfusions and outcomes
(22 Apr 2008: VIDYYA MEDICAL NEWS SERVICE) -- An exhaustive review and analysis of the medical literature by a panel of experts at the International Consensus Conference on Transfusion and Outcomes (ICCTO) held this month in Phoenix concluded that there is little evidence to support a beneficial effect from the greatest number of transfusions currently being given to patients. The vast majority of studies show an association between red blood cell transfusions and higher rates of complications such as heart attack, stroke, lung injury, infection and kidney failure and death.
The ICCTO conference brought together leading international physicians and scientists in the fields of anesthesiology, intensive care, hematology, oncology, surgery, and patient blood management, and was monitored by the Food and Drug Administration, the American and the Australian Red Cross, the Joint Commission, along with government health officials, and other organizations.
"The results of the conference firmly establish the view that, rather than being a benign procedure, blood transfusion is associated with increased risk of medical complications," said Aryeh Shander, M.D., Chief of the Department of Anesthesiology, Critical Care Medicine, Pain Management and Hyperbaric Medicine at Englewood Hospital and Medical Center in Englewood, NJ and a founding member of the Society for the Advancement of Blood Management (SABM). "The evidence tells us to restrict the practice of transfusion and to avoid unnecessarily transplanting stored blood that could harm a patient's recovery."
Safety concerns with blood initially came to the public's awareness with the realization that infectious agents such as HIV could be transmitted via blood transfusion. Careful screening and testing have resulted in the risk of known infectious agents being transmitted via blood being reduced to extremely low levels. Since then, concern has emerged amongst many in the medical profession that transfusion itself may be a risk factor for adverse patient outcomes. It has been known for some time that blood undergoes many physical and chemical changes during storage, losing its ability to supply oxygen to vital organs and triggering inflammatory and immune reactions when transfused. It is now thought by some that these storage-related problems may result in negative outcomes to patients.
ICCTO was convened by two professional medical societies, the USA based Society for the Advancement of Blood Management (SABM) and the international Medical Society for Blood Management (MSBM), out of concern for the lack of evidence supporting transfusion effectiveness and the growing number of studies reporting the association between transfusion and negative patient outcomes. Because blood transfusion came into medical use decades ago, it has never been subject to the same rigorous safety and efficacy assessment process applied today to other drugs and treatments before they are approved for use. This has resulted in a great deal of uncertainty and lack of knowledge among physicians as to whether a patient should or should not be transfused. As a consequence, there is enormous variation in transfusion practice between countries, states within countries, hospitals and even between clinicians within the same institution.
The accepted "consensus conference" process using the RAND-UCLA method was chosen to unravel some of this uncertainty. This method involves a comprehensive review of all published scientific studies on a treatment, after which a panel of experts assesses a series of patient scenarios using the scientific literature to determine whether the treatment has evidence to support that it will improve the patient's outcome.
The ICCTO panelists also considered what has come to be known as the Bradford Hill Criteria for establishing causation, the process Sir Austin Bradford Hill and Sir Richard Doll used in the 1960s to establish that cigarette smoking caused such diseases as lung cancer and emphysema.
The ICCTO literature review searched for all studies on blood transfusion and outcomes published in the last 13 years. 555 studies met study inclusion criteria and were analyzed by each panelist in preparation for the conference.
A great majority of these studies were initiated to investigate the benefits of transfusions, and instead either found no benefit or identified negative outcomes associated with blood transfusions. Only a small minority of clinical scenarios, were associated with suggested improved outcome.
The panel confined this initial ICCTO analysis to stable non-bleeding patients. Approximately sixty percent of the 90 million units collected around the globe each year (14 million units annually in the USA) are given to such patients.
"Given what we now know, donor transfusions should be limited only to surgery patients who are experiencing major bleeding that is difficult to control quickly," said James Isbister, MD, Clinical Professor of Medicine at the University of Sydney, and a founding member of MSBM. "We hope the conference will help all physicians and the public become aware of the many negative outcomes associated with transfusion, and call for blood management strategies to improve patient outcomes."
The two convening societies
SABM and MSBM are educational organizations comprised of a network of practitioners from a wide variety of medical and scientific disciplines who are dedicated to improving patient outcomes and the advancement of optimal patient blood management in clinical practice through education, cooperation and research. The societies work to facilitate cooperation among existing and future patient blood management/blood conservation, (and/or) bloodless medicine and surgery programs as well as enhance the clinical and scientific aspects of transfusion practice. Patient blood management seeks to optimize and conserve the patient's own blood, reducing or avoiding the need for a blood transfusion. Stored donor blood should only be used as therapy, with patient consent, when there are no alternatives, and when the expected benefits exceed the negative consequences. Additional information is available at www.sabm.org and www.bloodmanagement.org
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