On day 7, his right lower extremity was noted to be swollen. Ultrasound duplex revealed a nonocclusive thrombus within the right common femoral vein. He was started on therapeutic anticoagulation for deep vein thrombosis with enoxaparin, which was switched to unfractionated heparin (UFH) later, due to worsening renal function. On the same day, due to worsening respiratory failure, he was intubated and mechanically ventilated.