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?
Systemic anticoagulation with heparin infusion Systemic anticoagulation with warfarin Placement of an inferior vena cava filter Thrombolytic therapy