A physician-validated, board-style question from the Active Transport QBank. Try it, then check the reasoning for every option.
A 28-year-old woman presents to the emergency department with fever, cough, and difficulty in breathing for the last 6 hours. She also mentions that she noticed some blood in her sputum an hour ago. She denies nasal congestion or discharge, sneezing, wheezing, chest pain, or palpitation. Her past history does not suggest any chronic medical condition, including respiratory disease, cardiovascular disease, or cancer. There is no history of pulmonary embolism or deep vein thrombosis in the past. Her temperature is 38.3°C (101.0°F ), the pulse is 108/min, the blood pressure is 116/80 mm Hg, and the respirations are 28/min. Auscultation of her lungs reveals the presence of localized crackles over the right inframammary region. Edema is present over her left leg and tenderness is present over her left calf region. When her left foot is dorsiflexed, she complains of calf pain. The emergency department protocol mandates the use of a modified Wells scoring system in all patients presenting with the first episode of breathlessness when there is no history of a cardiorespiratory disorder in the past. Using the scoring system, the presence of which of the following risk factors would suggest a high clinical probability of pulmonary embolism?
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A
Use of oral contraceptives within last 90 daysIncorrect. OCP use is a real PE risk factor (estrogen increases hepatic synthesis of clotting factors and decreases protein S) but is not a component of the modified Wells score.
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B
History of travel of 2 hours in 30 daysIncorrect. The Wells score includes immobilization but does not credit a 2-hour travel within 30 days; prolonged immobility (typically >4 hours travel or recent bedrest >3 days) is what raises risk.
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C
History of surgery within the last 30 daysCorrect. Recent surgery within 4 weeks is a 1.5-point component of the modified Wells score for PE.
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D
History of smoking for more than 1 yearIncorrect. Smoking is a general thrombotic risk factor and contributes to vascular disease but is not part of the Wells PE scoring system.
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E
Family history of venous thromboembolismIncorrect. Family history of VTE suggests inherited thrombophilia (factor V Leiden, prothrombin gene mutation) and is a legitimate PE risk factor, but it is not a component of the modified Wells score.
↑ Tap an answer to reveal the reasoning
Answer: C. A young woman with acute dyspnea, hemoptysis, fever, focal lung crackles, and unilateral leg swelling with calf tenderness and a positive Homan sign has a clinical picture of pulmonary embolism with concurrent deep venous thrombosis. The modified Wells score for PE assigns points for: clinical signs of DVT (3 points), PE more likely than alternative diagnosis (3), heart rate >100 (1.5), immobilization or surgery within the previous 4 weeks (1.5), prior DVT/PE (1.5), hemoptysis (1), and malignancy (1).
Of the four answer choices, only "surgery within the last 30 days" is part of the Wells criteria - it captures recent immobilization or surgery as a major PE risk factor. Oral contraceptive use, recent short-distance travel, and smoking are clinically relevant PE risk factors but are NOT components of the Wells scoring system itself.
Clinical pearl for the boards: in patients with low or moderate Wells score, a D-dimer can rule out PE; in high-probability patients, proceed directly to CT pulmonary angiography (or V/Q scan if contrast is contraindicated).
**Why each option:**
**A.** OCP use is a real PE risk factor (estrogen increases hepatic synthesis of clotting factors and decreases protein S) but is not a component of the modified Wells score.
**B.** The Wells score includes immobilization but does not credit a 2-hour travel within 30 days; prolonged immobility (typically >4 hours travel or recent bedrest >3 days) is what raises risk.
**C.** Correct. Recent surgery within 4 weeks is a 1.5-point component of the modified Wells score for PE.
**D.** Smoking is a general thrombotic risk factor and contributes to vascular disease but is not part of the Wells PE scoring system.