Review Question - QID 220320

This patient who presents with signs and symptoms of deep venous thrombosis (DVT), tachycardia, and recent immobilization has 6 points using Wells criteria and should be evaluated with a CT angiogram of the chest.

Wells criteria is a set of points that can be used to assess for the risk of pulmonary embolism. These criteria include signs and symptoms of DVT (worth 3 points), pulmonary embolism (PE) is the most likely diagnosis (worth 3 points), pulse is 100/min or greater (worth 1.5 points), surgery within the past 4 weeks or immobilization for the past 3 days (worth 1.5 points), previously diagnosed PE or DVT (worth 1.5 points), hemoptysis (worth 1 point), and malignancy with treatment in the past 6 months (worth 1 point). Patients who score < 2 points are considered low risk and no evaluation is necessary. In some cases, it is possible to consider using a D-dimer to rule out the diagnosis in low risk patients. Patients who score 2-6 points are considered to be moderate risk and management is at the physician's discretion. Patients who score > 6 points are considered high risk and advanced imaging is required. CTA of the chest is the most appropriate test to diagnose a pulmonary embolism.

Kline reviews the evidence regarding the evaluation and diagnosis of a pulmonary embolism. He discusses how Wells criteria can be used to determine the risk of a pulmonary embolism. He recommends further evaluation in patients who are at high risk for this condition.

Figure/Illustration is a clinical photograph of the leg with asymmetric redness and swelling (red circle). These findings are consistent with a deep venous thrombosis.

Incorrect Answers:
Answer 1: Apixaban is reasonable as a treatment for deep venous thrombosis; however, given that this patient has a high risk for a concurrent pulmonary embolism, a CT angiogram should be performed to evaluate for this pathology and clot burden.

Answer 3: D dimer is a high sensitivity but low specificity test for a blood clot. Since this patient has a high risk for a pulmonary embolism, this is not an appropriate test for evaluation for this condition. It is instead used to rule out a blood clot when the risk is relatively low.

Answer 4: Lower extremity radiograph may be appropriate to evaluate for a traumatic etiology for leg pain and swelling; however, the most likely cause of this patient's symptoms is deep venous thrombosis and pulmonary embolism. Radiographs are not appropriate for the evaluation of this pathology; however, a DVT study (ultrasound) would be appropriate.

Answer 5: Warfarin is a reasonable long term treatment for blood clots; however, a heparin bridge would need to be initiated concurrently because this medication causes transient hypercoagulability. Furthermore, evaluation for a pulmonary embolism should be performed as a priority.

Bullet Summary:
Patients who are at high risk for pulmonary embolism per Wells criteria should be evaluated with a CT angiogram.