Bridging Anticoagulation
Bridging anticoagulation is when patients are changed from one form of anticoagulation medicine to another. This is often to prepare patients for surgery, dental work, giving birth or other invasive procedures. These are times when having blood too thin can cause complications.
Once Coumadin, an anticoagulation drug, is stopped, over the next four to five days the effect of the blood thinner wears off. During this time, as the patient is less anticoagulated, he may be at risk for clotting. Low molecular weight heparin (LMWH) is often used at this time to thin the patient’s blood. It is given as an injection under the skin and works immediately. The difference between LMWH and Coumadin is that LMWH is out of the patient’s system about 12 hours after it is given.
For example,
an anticoagulation patient is scheduled for surgery on Friday. He is instructed to stop taking his Coumadin on Monday. Throughout the week, as the effect of the Coumadin wears off, he is given LMWH to thin his blood. This medication can be stopped on Thursday and his blood will be normal by Friday, and then he can safely go to surgery.
Following the medical procedure, Coumadin will need to be restarted. In some patients, it is dangerous to simply restart this therapy because as the level of this drug builds, patients can be at higher risk for clotting. During this time, LMWH is used along with Coumadin to thin the blood until the Coumadin is effective. This process can take approximately five days.
In the above patient example, following surgery on Friday, the patient is started on both Coumadin and LMWH. The INR (international normalized ratio) is checked frequently, and when it is within the patient’s normal range for 48 hours, the LMWH is stopped.
Bridging of anticoagulation is very patient specific and will be tailored to meet each patient’s medical condition, circumstance and procedure.
