THE CASE
A 75-year-old woman presented to the primary care clinic with right-side rib pain. The patient said the pain started 1 week earlier, after she ate fried chicken for dinner, and had since been exacerbated by rich meals, lying supine, and taking a deep inspiratory breath. She also said that prior to coming to the clinic that day, the pain had been radiating to her right shoulder.
The patient denied experiencing associated fevers, chills, shortness of breath, chest pain, nausea, vomiting, constipation, diarrhea, or changes in stool color. She had a history of hypertension, for which she was taking lisinopril 20 mg/d, and hypercholesterolemia, for which she was on simvastatin 10 mg/d. She was additionally using timolol ophthalmic solution for her glaucoma.
During the examination, the patient’s vital signs were stable, with a pulse of 80 beats/min, a respiratory rate of 16 breaths/min, and an oxygen saturation of 98% on room air. The patient had no abdominal tenderness upon palpation, and the physical exam revealed no abnormalities. An in-office electrocardiogram was performed, with normal results. Additionally, a comprehensive metabolic panel, lipase test, and d-dimer test were ordered. Lab results showed an isolated elevated d-dimer of 2.66 mcg/mL (normal range, < 0.54 mcg/mL), while all other labs were normal.
THE DIAGNOSIS
Based on the lab results, a stat computed tomography pulmonary angiogram (CTPA) was ordered and showed a right segmental and subsegmental pulmonary embolism (PE; FIGURE 1).
DISCUSSION
PE shares pathophysiologic mechanisms with deep vein thrombosis (DVT), and together these comprise venous thromboembolism (VTE). Risk factors for VTE include hypercoagulable disorders, use of estrogens, active malignancy, and immobilization.1 Unprovoked VTE occurs in the absence of identifiable risk factors and carries a higher risk of recurrence.2,3 While PE is classically thought to occur in the setting of a DVT, there is increasing literature describing de novo PE that can occur independent of a DVT.4
Common symptoms of PE include tachycardia, tachypnea, and pleuritic chest pain.5 Abdominal pain is a rare symptom described in some case reports.6,7 Thus, a high clinical suspicion is needed for diagnosis of PE.
The Wells criteria is an established model for risk stratifying patients presenting with possible VTE (TABLE).8 For patients with low pretest probability, as in this case, a d-dimer is an effective diagnostic work-up, as a negative result will rule out PE. (If the d-dimer had been negative in this case, we would have considered other diagnoses, such as acute coronary syndrome, biliary colic, gastritis, pancreatitis, or musculoskeletal pain.) For high-risk patients, immediate anticoagulation and imaging should be performed, frequently with heparin and CTPA.9
Continue to: Length of treatment depends on gender and etiology