Diagnostic accuracy of point-of-care lung ultrasound in COVID-19

Background A promising modality for diagnosing pulmonary manifestations of COVID-19 in the emergency department (ED) is point-of-care ultrasound (POCUS) of the lungs. The currently used PCR as well as chest X-ray and CT scanning have important disadvantages. The aim of this study is to evaluate the diagnostic accuracy of POCUS in patients with suspected pulmonary manifestations of COVID-19 in the ED. Methods This prospective diagnostic accuracy study was conducted at the ED of our non-academic level 1 trauma centre (Isala, Zwolle, the Netherlands). Patients were enrolled between 14 April and 22 April 2020. Patients (aged >= 16 years) with suspected COVID-19 presenting to the ED underwent POCUS. All patients received current standard of care, including PCR (nasooropharyngeal swab). Outcome of POCUS was compared with PCR or CT scan outcome to determine diagnostic accuracy. Diagnostic accuracy measures were calculated using 2x2 contingency tables. Results 100 patients were eligible to participate in this study, data of 93 patients were analysed. 27 (29%) patients were found positive for COVID-19 by PCR or CT. POCUS had a sensitivity of 89% (95% CI 70% to 97%), specificity of 59% (95% CI 46% to 71%), negative predictive value of 93% (95% CI 79% to 98%) and positive predictive value of 47% (95% CI 33% to 61%). In a subgroup of patients without previous cardiopulmonary disease (n=37), POCUS had a sensitivity of 100% (95% CI 70% to 100%), specificity of 76% (95% CI 54% to 90%), negative predictive value of 100% (95% CI 79% to 100%) and positive predictive value of 67% (95% CI 41% to 86%). Conclusion POCUS of the lungs could serve as a valuable, radiation-free tool for excluding pulmonary manifestations of COVID-19 in patients in the ED at the point of assessment, especially in patients without previous cardiopulmonary disease.

Automated summary

The study evaluated the diagnostic accuracy of lung POCUS in patients with suspected pulmonary manifestations of COVID-19 in the ED, showing that POCUS was more sensitive and had a higher negative predictive value in patients without underlying cardiopulmonary disease.