Laboratory monitoring of patients on anticoagulants (warfarin and other therapies) makes up a large percentage of lab coagulation testing. Because of this, laboratorians sometimes think of coagulopathies only as conditions associated with prolonged clotting times. Laboratory staff don't typically see hypocoagulable patients as often as we see hypercoagulable patients (those with high INRs and prolonged aPTTs). It's important to remember that the reason many patients have prolonged clotting times is that they are taking anticoagulants because they have a condition that makes them prone to excessive clotting.
There are several relatively common conditions that make patients hypercoagulable. The spontaneous formation of thrombi is clinically quite serious. An embolism is an obstruction of an artery. Thromboembolisms can cause significant injury to downstream tissues and organs and result in death.
The most common type of thromboembolism is deep vein thrombosis (DVT). If a thrombus from a DVT dislodges and moves to the lung, a pulmonary embolism (PE) occurs. A PE is a medical emergency. In patients with PE, those who receive mechanical ventilation, cardiopulmonary resuscitation, or thrombolytic treatment still have very high mortality rates: 80%, 77%, and 30%, respectively.
