Computed Tomography Pulmonary Angiography Utilization in the Emergency Department During the COVID-19 Pandemic

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.

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.

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).

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.