Anticoagulants are drugs that work to prevent blood clotting. They perform a life-saving service for people who have:

• Congenital or inherited heart defects
• Had a heart valve replacement
• Heart rhythm disorders like atrial fibrillation
• Clotting disorders
• A high risk of a heart attack or stroke
• Had prior complicated surgeries

A blood clot forms to stop wounds from bleeding, but can block vessels and stop blood flow to organs like the brain, heart or lungs if they’re in the wrong place.

Sometimes anticoagulants are too effective

Blood thinners are very effective, but sometimes too much so. For example, warfarin, known by the brand name Coumadin, can increase risk of serious bleeding problems even when the dose may be at the recommended level.

The condition is serious enough that Marshfield Clinic has an Anticoagulation Services Department staffed by registered nurses. These specially-trained nurses work by phone with patients on warfarin. The nurses monitor nearly 11,000 patients per year.

Mandatory for patients on warfarin

“This service started as a pilot program in 1999,” said Melissa Mikelson, Anticoagulation Services manager. “In 2006 the service became a mandatory care management program at the Clinic for all patients on warfarin.”

While the program focuses on warfarin use, nurses also check other blood thinners. Aspirin is a well-known pain reliever that may not block clotting enough. Clopidogrel, or Plavix, is an antiplatelet medicine that does not need regular blood test monitoring but in rare cases can cause bleeding.

Registry helps nurses track status

“Nurses call patients regularly and have a registry to enter their current status,” Mikelson said. Based on lab results which are automatically sent to the Anticoagulation Service, nurses manage patients’ warfarin medication, provide education and coordinate care with their heart specialist or primary care provider.

The service has been broadened to include some patients not using warfarin who are referred by departments, like Oncology, for help monitoring medications and their effects, Mikelson added.