Although they found that small blood pressure changes that often occur with protamine's use are associated with increased mortality, they do not advocate any change in the clinical use of the drug. However, they do emphasize that their findings should spur development of alternatives for protamine.
Protamine, a drug purified from salmon sperm, is given to patients intravenously after bypass surgery to counteract the effects of the anticoagulant heparin, given during surgery. Heparin prevents clots from forming in the heart-lung machine, which oxygenates and pumps blood for the body while the heart is stopped.
Since protamine's approval in the early 1960s, no drug has been approved by the Food and Drug Administration (FDA) to reverse the properties of heparin.
"Without protamine to effectively reverse the properties of heparin, bypass surgery would not have reached the successful point where it is today," said Duke anesthesiologist Ian Welsby, M.D., who presented the results of the Duke study today (March 25, 2003) at the 77th Clinical and Scientific Congress of the International Anesthesia Research Society.
"We have long known that an extremely small proportion of bypass patients have severe allergic reactions to protamine, including sharp blood pressure changes and cardio-vascular collapse," Welsby continued. "We, however, wanted to see if smaller changes in blood pressure in response to protamine were related to any adverse effect on the outcomes of these patients."
Duke anesthesiologists have developed a system that continually records blood pressures of patients during and after surgery. For this study, they retrospecti
Contact: Richard Merritt
Duke University Medical Center