Evaluation of the Relationship between Exhaled CO Levels with Clinical Course and Parenchymal Involvement in COVID-19.

Abstract

COVID-19, caused by the SARS-CoV-2 virus, has infected nearly 270 million people over the past two years. We aimed to determine the exhaled CO levels of patients hospitalized with COVID-19 pneumonia and its correlation with parenchymal involvement. Between September 2021 and December 2021, 74 patients who were hospitalized in the infectious diseases service of our hospital and whose delta variant COVID-19 infection was confirmed with real-time PCR method were included in the study. The patients were analyzed in 3 groups: moderate COVID-19 (group 1), severe COVID-19 without macrophage activation syndrome (MAS) (group 2), and severe COVID-19 with MAS (group 3). While it was observed that the exhaled CO levels were higher in patients in Group 3 at the time of hospitalization than in patients in Group 1 and 2, it was determined that no significant difference was observed between the groups at the time of discharge (p < 0.001, 0.213). CT scores obtained at the time of hospitalization were also observed to be statistically significantly higher in patients in Group 3 when compared to patients in Group 1 and 2 (p = 0.002). In the correlation analysis of the exhaled CO levels and the CT scores at the time of hospitalization, a statistically significant positive correlation was observed (r = 0.628, p < 0.001). In COVID-19, which has a high affinity for lung tissue compared to other known viral lower respiratory tract infections, the exhaled CO level may be a non-invasive parameter that can be used in the evaluation of parenchymal involvement and clinical course.