We will discuss a case of unsuspected pulmonary embolism (UPE) to provide a framework for clinicians when approaching This newly encountered diagnosis. A 56‐year‐old female presented to our level 1 trauma center after a low‐speed motor vehicle accident. The patient complained of moderate neck pain. She had a history of depression, hypertension, and degenerative joint disease. Her medications included atenolol, bupropion, cyclobenzaprine, gabapentin, lisinopril, oxycodone, and pregabalin. She did not smoke, drink alcohol, or use illicit drugs. The patient was obese, single, and not sexually active. Her family history was unremarkable. The review of systems revealed mild cervicalgia. but was otherwise normal. Her physical exam revealed normal vital signs, obesity, and miid cervical muscle tenderness. A chest CT was done per the trauma protocoL Routine labs were within the normal limits. A D‐dimer was 4.3 mg/L (0.5‐2.1 mg/L). The chest CT was read as “a filling defect consistent with pulmonary embolism.” The patient had no signs or symptoms of pulmonary embolism and had no risk factors for pulmonary embolism. In particular, the patient had no recent bed rest, travel, or surgery. Nor did she have a history of clotting disorder, smoking, or estrogen use. Hence, we were faced with a diagnostic dilemma.
The postlest odds of PE in Ihis case is 1.02, or a posttest probability of 0.51 (Table 1). As multidector computed tomography (MDCT) is not the gold standard for The diagnosis of PE, the posttest probability of 51% is insufficient to confirm the diagnosis. Therefore, a V/Q scan was done: it was read as very low probability. This result did not move our diagnostic certainty out of the intermediate range. Doppler ultrasound of the lower extremities was normal, leaving us still with an intermediate probability of disease. Last, a standard pulmonary angiogram revealed a filling defect, confirming the diagnosis of UPE. Our assumption of the pretest probability for purposes of our analysis was based on best data available. Small case series suggest the prevalence of UPE is up to 6% (Table 2). Although long‐term follow‐up of untreated UPE demonstrates minimal adverse sequelae, the decision to withhold treatment for UPE is still vexing. Evidence for safely withholding anticoagulation in our patient is lacking, so we chose to anticoagulate her per Goodman et al.
Until a new gold standard for the diagnosis of PE is available, clinicians must continue to use Bayes' Theorem and The best available evidence to aid their diagnostic decision making. Scenarios for withholding anticoagulation in unsuspected and asymptomatic pulmonary embolism include: when the emboli are small, there is no evidence of DVT, The patient has adequate cardiopulmonary reserve, and anticoagulation is contraindicated. These recommendations are based on level C evidence.
M. Radzienda, none.