Correlation between chest CT severity scoring system with oxygen saturation and laboratory inflammatory markers in adult patients with COVID-19 infection

BACKGROUND: COVID-19 pneumonia is responsible for the latest pandemics. Chest computed tomography (CT) scan is known to be an essential tool for diagnosis of COVID-19. In this research, the relationship between on-admission chest CT severity score, capillary blood oxygen saturation level, and laboratory inflammatory markers results in patients with SARS-COV-2 pneumonia was investigated. METHODS: This prospective analytical study was conducted in COVID-19 isolation unit, Zagazig University Hospitals, from 1st to end of April 2021. Adult patients with COVID-19 infection were included. Chest CT scan was performed for all patients, and CT severity score was computed. The initial capillary oxygen saturation was also assessed at the time of admission. The information was gathered and analyzed. RESULTS: A total number of 305 COVID-19 patients were involved in the study with the following data: age, gender, presence of co morbidities, capillary blood oxygen saturation, laboratory tests including absolute lymphocytic count, CRP, D-dimer and ferritin levels, as well as chest CT severity score. Based on chest CT severity score, we found that 110 cases (36.1%) were mild, 163 cases (53.4%) were moderate, and 32 cases (10.5%) were severe, with significant male predominance among moderate and severe cases. The initial measurements of blood oxygen saturation values revealed that mean blood oxygen saturation was 95.6% among mild to moderate cases and 85.4% among severe cases. Furthermore, there was a high statistically significant negative correlation between chest CT severity score and absolute lymphocytic count of studied cases, while there was a statistically significant positive correlation with D-dimer, CRP and ferritin levels. CONCLUSIONS: CT scans can help clinicians in developing a management strategy and serve as a predictor of illness severity and possible outcomes. In individuals with COVID-19 infection, the severity of a chest CT scan is positively correlated to inflammatory markers and oxygen demand.