Usefulness of Lung Ultrasound Examinations Performed by Primary Care Physicians in Patients With SuspectedCOVID-19

Objectives In patients with suspected coronavirus disease 2019 (COVID-19) consulting primary care (PC) centers, clinical criteria may not be sensitive enough to detect many cases in which complications first occur. We intended to assess whether lung ultrasound (LUS) examinations performed by PC physicians are a useful tool to detect lung injury and may help in decisions about hospital referral. Methods This study included 61 patients with moderate symptoms suggesting COVID-19 who were evaluated with LUS by PC physicians and then referred to a hospital during the current pandemic peak in Madrid. We analyzed association of a simple self-designed LUS severity scale (grade 0, normal; grade 1, multiple separated B-lines, pleural irregularity, or both; and grade 2, coalescent B-lines, consolidations, pleural effusion, or a combination thereof) with the main outcome indicating adequacy of hospital referral, and also with chest x-ray (CXR) findings. Results The proposed LUS severity scale was significantly associated with the main outcome of appropriate referral (P= 0.001): the higher the scale, the higher the percentage of adequate referrals. The LUS scale was also associated with a CXR severity scale (P= 0.034). The presence of coalescent B-lines was the only independent LUS finding significantly associated with the appropriate-referral outcome (P=0 .008) and also with a higher probability of hospital admission (P= 0.02) and with several CXR findings. Conclusions This study supports the use of LUS in PC as a tool to assess patients with suspected COVID-19. Its use can reduce uncertainty during clinical evaluations of moderate patients, facilitate early detection of lung involvement, allow early appropriate referral, and avoid unnecessary referral.