Decreasing bleeding risks in the operating room

When an infant undergoes open-heart surgery, doctors don’t know how the baby’s blood clotting system will react. In about 20 percent of cases, bleeding can become a serious problem.

Now a new multiyear study, led by D. Woodrow Benson, MD, PhD, director of research at the Herma Heart Center, and James Tweddel, MD, medical director of Cardiothoracic Surgery, aims to better predict potential blood clotting problems and customize care in the operating room. The Blood Research Institute, the research arm of the BloodCenter of Wisconsin, is a key partner.

“We hope to take advantage of resources that we have, both in our excellent infant heart surgery program, and also with world-class investigators at the Blood Research Institute,” Dr. Benson says. “They can help us break down this clinical problem at the bedside into a series of research questions that could be answered at the laboratory bench.”

During cardiopulmonary bypass, in which surgical patients are connected to a machine that pumps blood through the body while the heart is stopped, patients receive an anti-clotting drug and are cooled down to slow coagulation. After surgery, doctors raise the patient’s body temperature and give another medication to reverse the anti-clotting as the heart and lungs begin working on their own.

“It could take 15 to 20 minutes, or it could take several hours. And what we learned is that sometimes the biggest time factor in the operating room is the time spent waiting until bleeding is under control,” Dr. Benson says. “So all patients get the same regime, because we don’t know how to tell who are going to be the babies that have bleeding problems and who will be the ones who will come back to normal very quickly.”

If doctors know in advance how well a baby’s blood clots, they could be better prepared for problems or avoid unnecessary overtreatment. The study’s overall goal is to minimize the administration of blood products — which mostly come from adult donors — because infants’ blood works differently from adult blood, and there’s the risk of infection and other complications.

“There are very powerful factors that you could give that may actually change the problem from too much bleeding to too much clotting, where now you start getting blood clots forming inappropriately. Then that can cause problems,” Dr. Benson explains. “Fortunately, those things don’t happen very often, but right now we don’t have any way of knowing the risk factors before the surgery.”

Ultimately, researchers hope to develop a point-of-care test that could instantly tell the operating room team which blood products a baby needs instead of waiting for conventional laboratory results. 

“If this works out the way that we hope it would, then we would use it to make decisions about what gets administered when we’re reversing the cardiopulmonary bypass,” Dr. Benson says. 

And that could mean a safer and speedier operating room experience for the youngest heart patients.