Coagulation assays.

Case 1: Mr F, a 75-year-old man with diabetes, was admitted with non–ST-segment-elevation acute coronary syndrome. In addition to other medications, he is receiving 1 mg/kg enoxaparin every 12 hours. He is scheduled for cardiac catheterization later in the afternoon. Earlier this morning, his activated partial thromboplastin time (aPTT) was 30 seconds. How should his anticoagulants be managed? Case 2: Mrs G was admitted with chest pain and shortness of breath. A ventilation-perfusion lung scan was consistent with a large pulmonary embolism. Because of renal dysfunction, initial therapy consisted of unfractionated heparin. After 2 days of intravenous heparin and 5 mg/d warfarin, her aPTT is 48 seconds, and her international normalized ratio (INR) is 1.3. She is currently receiving 45 000 U heparin per day. How should her anticoagulants be managed?