LAUSR

Purpose: To determine if computed tomography pulmonary angiography (CTPA) ordering increased significantly during the COVID-19 pandemic in an emergency department (ED) setting; if positive findings for pulmonary embolism (PE) increased to the same degree; and whether COVID-positive patients have a higher incidence of PE than COVID-negative patients at ED presentation. Materials and Methods: We conducted a retrospective review of CTPA performed in our ED between June and December in 2019 and 2020. We collected data on patient demographics, symptoms, COVID-19 status, lab and imaging results, and risk factors for PE. We used a Wilcoxon rank sum to analyze quantitative variables and χ2 or Fisher test for categorical variables. We used logistic regression to identify predictive factors for PE. Results: CTPA ordering increased from 432 studies in 2019 to 699 in 2020 (+61.8%, P<0.0001), but detection rates for PE remained stable (11.3% vs. 10.2%, P=0.61). In 2020, 10 of 91 COVID-positive patients undergoing CTPA had positive studies. On regression analysis, COVID-19 was not a significant predictor of PE at ED presentation (odds ratio 1.029, 95% confidence interval: 0.959-1.103). COVID-positive patients were more likely to have nondiagnostic imaging (7.7% vs. 2.5% [COVID-negative] and 0.8% [not tested], P=0.007). Conclusions: While CTPA ordering increased significantly during the pandemic, our positivity rate remained stable, suggesting that this increase was appropriate. COVID-positive patients who underwent CTPA in the ED did not have a higher incidence of PE than other patients. Clinicians should use clinical judgment to weigh the likelihood of PE against the risk of nondiagnostic results when determining whether to expose COVID-positive patients to high-dose radiation and contrast with CTPA on initial presentation.