Jun. 16, 2010
Anti-bleeding Drugs Saves Lives in Trauma Patients, Study Shows
Emory University editorial in The Lancet says the study is impressive
A class of drugs that prevent clot breakdown and reduce internal bleeding could save lives after trauma, according to an editorial in the June 15, 2010 issue of The Lancet.
Jerrold H. Levy, MD, FAHA, professor of anesthesiology at Emory University School of Medicine and co-director of cardiothoracic anesthesiology, is author of the editorial. The editorial accompanies a report on a randomized clinical trial evaluating the use of the antifibrinolytic agent tranexamic acid in more than 20,000 trauma patients from 42 countries.
Antifibrinolytics have been employed extensively in cardiac and orthopedic surgeries. Tranexamic acid, delivered orally, was also approved by the FDA for heavy menstrual bleeding in 2009. However, antifibrinolytics' use with trauma patients has not been studied rigorously before.
"The current study, demonstrates that inhibiting fibrinolysis following major trauma with tranexamic acid represents an important mechanism of reducing mortality," Levy writes. "It is quite impressive based on the number of patients studied around the globe."
Levy was not involved in the tranexamic acid clinical trial, which was initially supported by the London School of Hygiene, the Bupa Foundation and the Moulton Charitable Trust and now is being funded by the United Kingdom's National Institute for Health Research.
The mortality rate from all causes was 14.5 percent in the tranexamic acid group compared to 16 percent with placebo. Bleeding related mortality was also reduced 4.9 percent compared to 5.7 percent, respectively, without an increase in blood vessel-blocking clotting events.
Although there were 93 fewer patients requiring blood transfusions in the tranexamic acid group (less than one percent), the differences in transfusion requirements were not statistically significant.
This, notes Levy, is likely due to all of the complex factors that affect bleeding, and potential variability of injury that occurs in trauma patients.
Tranexamic acid inhibits the activation of the enzyme plasmin, which degrades fibrin, a structural component of coagulation proteins and blood clots. Levy suggests that inhibiting the enzyme plasmin may have additional beneficial effects that include systemic antiinflammatory effects, potentially attenuating organ damage after trauma.
Levy also adds a note of caution, pointing out that in cardiac surgery, transexamic acid appears to be linked to a small but increased risk of postoperative seizures. However, often the doses given in cardiac surgery are several times higher than the current trial.
The Robert W. Woodruff Health Sciences Center of Emory University is an academic health science and service center focused on missions of teaching, research, health care and public service.