Review Question - QID 103425

The patient’s presentation (tachypnea, tachycardia, pleuritic chest pain, hemoptysis, immobilization (from Achilles injury), and likely deep vein thrombosis (DVT)) is highly consistent with a pulmonary embolism (PE). Given the high suspicion for a PE (a Wells score of 10), treatment with heparin can be started prior to diagnostic tests.

Pulmonary embolism (PE) typically presents with pleuritic chest pain, tachypnea, and dyspnea, while some also have evidence of concomitant deep venous thromboembolism. The diagnostic workup of a PE depends on Wells criteria:

1. Findings of a DVT (3 points)
2. PE is most likely diagnosis (3 points)
3. Heart rate > 100/min (1.5 points)
4. Immobilization for 3 days or surgery in past 4 weeks (1.5 points)
5. Previous PE or DVT (1.5 points)
6. Hemoptysis (1 point)
7. Malignancy within 6 months or palliative care (1 point)

A low risk patient (< 2 points) can be worked up with a D-dimer. An intermediate risk patient (2-6 points) can be worked up with a D-dimer or CT angiogram pending clinical suspicion. A high-risk patient (score > 6 points) should be worked up with a CT angiogram (a D-dimer should not be used). The only exception to this rule is in very high risk patients with a classic presentation for PE who have unstable vitals. In these patients, it is appropriate to first treat with heparin while a CT angiogram is being ordered/performed to confirm the diagnosis.

Figure A is an ECG demonstrating right axis deviation and sinus tachycardia which is suggestive of a pulmonary embolism. There are also non-specific repolarization changes seen throughout.

Incorrect Answers:
Answer 1: CT angiogram is used in the diagnosis of a PE (intermediate and high risk patient); however, given the high suspicion for PE, anticoagulation can be started first.

Answer 2: D-dimer is most useful in a low risk patient (< 2 points) for ruling out a PE; however, it would be inappropriate in this patient as a negative D-dimer would still require a CT angiogram to rule out the diagnosis.

Answer 4: Tissue plasminogen activator (TPA) is a thrombolytic agent and is the first-line treatment for a patient with a PE who is unstable. It is true that this patient is currently hypotensive and tachycardic; however, he is perfusing well (given is normal mental status). For this reason, TPA can be held until the diagnosis is confirmed with either a bedside ultrasound or a CT angiogram given the risks of bleeding with this treatment.

Answer 5: Ultrasound can be performed bedside while this patient is receiving heparin. However, for the boards, patients with a high risk of a PE should immediately be treated while further workup is performed. Once the diagnosis of a PE is confirmed (with a CT angiogram or an ultrasound) TPA could be given to this patient given his hypotension and tachycardia if he does not respond to oxygen and IV fluids.

Bullet Summary:
Patients with an extremely high likelihood of a pulmonary embolism can be treated with heparin prior to further diagnostic testing.