You are called by the emergency department and told of a 75-year-old male nonsmoker with a history of coronary artery disease and hypertension who presents with pleuritic chest pain with dyspnea. You are asked to admit this patient to the hospital for a pneumonia seen on chest x-ray. The patient is febrile and tachypneic, and has a blood pressure of 145/65, a pulse of 115, and an oxygen saturation of 87% on room air. Physical examination shows right lower extremity edema with tenderness. Laboratory studies show a white blood cell count of 14,000, no evidence of acute renal failure, and a positive D-dimer. Blood cultures have been obtained and levofloxacin has been started in the emergency department.
1. What is this patient's risk of a coexisting pulmonary embolism?
2. How could you diagnose a pulmonary embolism in this patient?
3. When should treatment start for a suspected PE?
4. What are the initial treatment options for PE in hemodynamically stable patients?
5. Is it worthwhile to evaluate this patient for a DVT?
The patient is at moderate risk for a coexisting pulmonary embolism. The patient's Wells score, a clinical risk stratification for VTE described in Table 29-2, is 4.5 (+3 for signs/symptoms of DVT, +1.5 for tachycardia). Pneumonia can cause a positive D-dimer in the absence of venous thromboembolism.
Either a ventilation perfusion (V/Q) scan or a CT angiography of the chest is acceptable for a first-line diagnostic strategy depending on the expertise at your institution. CT angiography is the preferred choice in most settings due to availability, speed, and the ability to evaluate for other potential causes of chest pain and dyspnea. Pulmonary angiography is rarely performed for the diagnosis of PE due to the risk, limited availability, and cost of this procedure. A positive D-dimer alone is not specific for PE.
Treatment for suspected PE should be initiated quickly, while waiting for confirmation of the PE in patients with no contraindications for systemic anticoagulation. Treatment can be discontinued if no PE is found. Patients should be evaluated for contraindications to anticoagulation before starting anticoagulation. If a contraindication to anticoagulation is found, an alternative strategy such as an inferior vena cava (IVC) filter will need to be developed.
Both intravenous unfractionated heparin and subcutaneous low-molecular-weight heparin (LMWH) are effective treatments for acute PE. Warfarin, for long-term treatment, is often started at the same time. Warfarin will take several days to become effective. Aspirin and Plavix have not been shown to be effective for the treatment of PE. The role of thrombolytic therapy for acute PE is controversial, and is only considered in patients with hemodynamic compromise. No treatment is always an option, and may be the patient's preference after discussing the risks of systemic ...