Dale Reisner has decided not to use donor blood during her open heart surgery.

"It's a precious resource. It's a limited commodity," she said.

As a surgeon herself, Reisner knows how limited the blood supply can be.

"It's really used best for trauma and acute surgical emergencies," she said.

Bloodless surgery used to be requested mostly for religious reasons. Now there medical reasons as well. Studies show transfusions lead to more infections and complications. But not everyone is getting the message.

"We're probably using blood transfusions too commonly and too regularly and using it for patients who don't need it," said Dr. Lori Heller, a bloodless surgery expert at Swedish Medical Center.

Reisner had hormone injections to boost her blood count. Now, doctors will transfuse her with her own blood during the surgery if she needs it.

Other ways to avoid transfusions include a cell salvage machine collects blood during surgery, filters it and returns the patient's own red blood cells.

New blood testing techniques only need a drop, rather than a whole tube, of the patient's blood.

All of these techniques mean safer surgeries and saving a precious resource for emergencies.

Medical studies have also shown that donated blood may reduce a person's immunity.

That can make it more difficult to fight off infections or recover from illnesses.