The Best Treatment for Pulmonary Embolism Is Prevention

The best treatment for Pulmonary embolism is prevention. Heparin is often used to prevent pulmonary embolisms in at-risk patients. The Activated Partial Thromboplastin Time (APTT) is used to maintain a therapeutic level for heparin therapy. What level should the Activated Partial Thromboplastin Time be maintained at?

A) 1.5 to 2 times the normal level
B) 2.5 to 3 times the normal level
C) 3 to 4 times the normal level
D) 5 times the normal level