Implementing Lung Ultrasound in the Outpatient Management of COVID-19 Pneumonia: A Pilot Study to Update Local Guidelines

Background: Lung ultrasound (LUS) has a good performance with a high sensitivity and specificity for the diagnosis of pneumonia compared with chest X-ray, and it has been extensively used to assess patients during the COVID-19 pandemic. This study aims to evaluate the potential advantages of the regular use of LUS for the assessment of the severity and prognosis of COVID-19 pneumonia and to propose an adapted protocol with its inclusion in current local validated and published guidelines. Methods: This is a single-center prospective study conducted during the first (April–May 2020) and second (October 2020–January 2021) waves of the SARS-CoV2 pandemic in Switzerland. All adult patients presenting to dedicated test centers with a suspicion of mild-to-moderate COVID-19 pneumonia and not requiring hospitalization at the time of diagnosis were included. Patients with confirmed COVID-19 pneumonia were referred to an ambulatory follow-up unit at our institution for reassessment, with the inclusion of the use of LUS in a random selection. Descriptive statistics were calculated for demographics using percentages, means, and standard deviations according to the distribution of variables. Results: Eighty-eight ambulatory patients with a confirmed COVID-19 pneumonia were included (men = 57 [59%]; mean age, 52.1 ± 13.5 years). Among these, 19 (21%) were hospitalized and none died. Twenty-five lung assessments by ultrasound were performed during the follow-up consultation. All were consistent with the clinical examination and confirmed the clinician's opinion. Conclusion: The use of a standardized pleuro-pulmonary ultrasound protocol for ambulatory patients with COVID-19 could help to reduce the use of chest X-rays and improve overall management at the time of referral and eventual follow-up. However, a specific study including LUS in a systematic approach should be performed to evaluate the outcome of patients according to findings.