Lung Ultrasound as a Triage Method in Primary Care for Patients with Suspected SARS-CoV-2 Pneumonia

Abstract

Background: Currently, there are few studies that have analyzed the benefits of using lung ultrasound in the field of primary care, including in homes and nursing homes, for patients with suspected COVID-19 pneumonia and subsequent follow-ups. The aim of this study was to demonstrate that lung ultrasound is a useful technique for triaging these patients. Methods: An observational and retrospective study of individuals who presented with clinical suspicion of SARS-CoV-2 pneumonia was carried out during the months of March to June 2020 in Health Center number 2 of Ciudad Real and in homes of patients and nursing homes belonging to the Health Service of Castilla-La Mancha (Spain). Results: A total of 209 patients, of whom 86 (41.1%) were male, were included in the study. The most frequent ultrasound findings were bilateral B-lines, with a right predominance, specifically in the posterobasal region. Additionally, there was a statistical significance (p < 0.05) correlation between pathological positivity on lung ultrasound and PCR and chest X-ray positivity. When calculating the sensitivity and specificity of ultrasound and X-ray, ultrasound had a sensitivity of 93%, and X-ray had a sensitivity of 75%. Conclusion: Due to its high sensitivity and negative predictive value, lung ultrasound is very useful as a triage tool for patients with suspected SARS-CoV-2 pneumonia.

Keywords: B-lines; COVID-19; lung ultrasound; pneumonia; primary care.

Figure 1

Main symptoms of patients.

Figure 2

Comparison of the areas under the curve for pathological lung ultrasound, pathological chest CT and pathological chest X-ray.