A 55-year-old man is admitted to the critical care unit following a severe motor vehicle accident. He is intubated on assist-control ventilation and receiving a continuous norepinephrine infusion for hemodynamic support via a central venous catheter. He has no history of bleeding disorders, with normal platelet count and renal and hepatic function. On hospital day 5, he develops acute shortness of breath and pleuritic chest pain. CT pulmonary angiography confirms a new pulmonary embolism in the right main pulmonary artery, provoked by his recent major trauma and immobilization. Therapeutic anticoagulation with unfractionated heparin is initiated. What is the most appropriate minimum duration of primary therapeutic anticoagulation for this patient’s provoked pulmonary embolism?

A 65-year-old man is in the intensive care unit for severe septic shock secondary to pneumonia. He requires mechanical ventilation and a continuous norepinephrine infusion administered via a central venous catheter. Laboratory results include a white blood cell count of 22,000/mm³, a platelet count of 80,000/mm³, and a D-dimer of 8,500 ng/mL (normal <500 ng/mL). Despite receiving enoxaparin 40 mg daily for VTE prophylaxis, he develops acute left leg swelling on hospital day 7. A Doppler ultrasound confirms a new deep vein thrombosis (DVT). Given the patient's underlying septic shock and the development of a DVT despite prophylaxis, which component of Virchow's triad is the MOST significant contributor to this thrombotic event?

A 45-year-old patient experienced an unprovoked deep vein thrombosis (DVT) 8 months ago and was prescribed apixaban. The patient discontinued the medication after 3 months, stating, “I didn’t understand why I needed it long-term since I felt fine, and the cost was becoming an issue.” Which factor most likely contributed to this patient’s non-adherence?

A 62-year-old man with septic shock is receiving mechanical ventilation (FiO₂ 0.80, PEEP 8 cmH₂O) and a continuous norepinephrine infusion at 0.1 mcg/kg/min through a right internal jugular central venous catheter. Vital signs are: temperature 38.2 °C, blood pressure 88/54 mmHg, heart rate 115 beats/min, respiratory rate 22 breaths/min, SpO₂ 88%. He develops sudden onset dyspnea and pleuritic chest pain. Examination reveals a right calf that is warm, tender, and 4 cm larger in circumference than the left. A bedside echocardiogram shows new right ventricular dilation. Which of the following is the MOST appropriate initial test to confirm the likely diagnosis?

A 62-year-old man was admitted to the ICU with a massive pulmonary embolism requiring vasopressor support and mechanical ventilation. He has now been extubated, is stable, and has completed 3 months of rivaroxaban for an unprovoked PE. The team is considering routine D-dimer testing and a repeat lower extremity ultrasound to assess for residual thrombosis to inform the decision about stopping anticoagulation. He has no history of bleeding and a HAS-BLED score of 1. Based on current evidence, which statement best describes the utility of these tests for determining the duration of anticoagulation in this patient?

A 65-year-old man is evaluated in the clinic 3 months after a total hip arthroplasty complicated by pulmonary embolism. He has completed a 3-month course of rivaroxaban. His serum creatinine is 1.0 mg/dL (eGFR 80 mL/min/1.73 m2), and his HAS-BLED score is low. He is asymptomatic, ambulates without difficulty, and has no signs of recurrent venous thromboembolism or bleeding. Which of the following is the most appropriate next step in managing his anticoagulation?

A 62-year-old man suffered a right lower extremity deep vein thrombosis and a subsegmental pulmonary embolism 3 months ago after prolonged immobilization and central venous catheter placement following a motor vehicle accident. He has completed a 3-month course of therapeutic enoxaparin, his central line has been removed, he is ambulating independently, and he is due to transfer to a rehabilitation facility. Which of the following is the most appropriate next step in managing his anticoagulation?

A 62-year-old man is in the ICU, intubated and on mechanical ventilation following a severe stroke that resulted in dense hemiplegia. He has no prior history of thromboembolism or bleeding disorders, and his renal and hepatic function are normal. A new right lower extremity deep vein thrombosis (DVT) is diagnosed by ultrasound, provoked by prolonged immobility. Therapeutic enoxaparin is initiated. Given that his mobility is expected to improve over the next several months, what is the most appropriate duration of primary anticoagulation therapy?

A 62-year-old man with severe chronic obstructive pulmonary disease is in the ICU on assist-control ventilation. His BMI is 28 kg/m2 (weight 85 kg, height 1.75 m). Vital signs are stable: T 37.0 °C, BP 125/75 mmHg, HR 88 bpm, SpO2 95% on FiO2 0.4. Physical exam reveals bilateral diffuse wheezes. Six months ago he was diagnosed with an unprovoked pulmonary embolism and completed a standard 6-month course of rivaroxaban. A recent D-dimer is negative, and his HAS-BLED score is 1. Which of the following is the most appropriate next step in his anticoagulation management?

A 62-year-old man is evaluated in the thrombosis clinic for follow-up. Three months ago, he presented to the emergency department with spontaneous right leg swelling and was diagnosed with a proximal deep vein thrombosis (DVT) in the femoral vein. He had no recent surgery, trauma, or prolonged immobility, and a workup for underlying malignancy was negative. He has just completed a 3-month course of rivaroxaban, reports no bleeding complications, and his leg swelling has resolved. The clinic nurse documents that he is ambulating without difficulty. After completion of the initial 3-month treatment course, which of the following is the most appropriate long-term anticoagulation strategy for this patient?