Following pelvic gynecologic surgery, a 34-year-old woman becomes dyspneic, her peripheral aerial O2 saturation falls from 94% to 81%, and her measured PaO2 is 52 on a 100% non-rebreather mask. She is hemodynamically stable. A CT angiogram is consistent with a right lower lobe pulmonary embolus. Which of the following is the next step in her management?

The initial treatment for venous thromboembolism (VTE) which includes deep venous thromboses (DVTs) and pulmonary emboli (PEs) is systemic anticoagulation with either unfractionated heparin--by bolus and infusion-- or low molecular weight heparins--by subcutaneous administration. Transition is then made to oral warfarin, which is a vitamin K antagonist. Warfarin is not the initial treatment because it requires several days to become therapeutic and proteins C and S (which are anticoagulants) are inhibited first resulting in a procoagulant state. Inferior vena cava (IVC) filters are indicated in patients for whom anticoagulation is contraindicated or in patients who develop recurrent VTE in the setting of adequate anticoagulation. Thrombolytic therapy and pulmonary embolectomy are typically reserved for patients with massive PEs with hemodynamic instability.