Pulmonary Manifestations of “Long COVID” (Post–COVID-19)

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (coronavirus disease 2019 [COVID-19]) infections began in late 2019/early 2020 and quickly achieved pandemic proportions. Of significance is that, while most individuals recover, some do not. Those who have persistent symptoms are diagnosed with long COVID, or post-COVID syndrome. Individuals with long COVID develop symptoms related to multiple organ systems. One of the more frequent systems affected is the pulmonary system. Individuals develop shortness of breath and/or fatigue. These are sometimes unrelated to any abnormalities on physiological or radiographic testing. More frequently, however, there are abnormalities found radiographically (especially on computed tomography) and on physiological testing (generally, abnormalities in the diffusion capacity for carbon monoxide or in a 6-minute walk test with the oxygen saturation being measured during the test). This article reviews many published articles and is organized by the duration of signs, symptoms, and/or testing abnormalities after the initial diagnosis of COVID-19. The date of maximum medical improvement is suggested to be 12 months, although currently this cannot be definitively supported. More time will need to pass so that appropriate data can be collected.