Association of laboratory markers with oxygen saturation and radiological findings in hospitalized COVID-19 patients

Aim: of the study was to evaluate the association of COVID-19 symptoms and certain laboratory markers with oxygen saturation (SaO2) and radiological findings in hospitalized COVID-19 patients. Methods: Retrospective cohort study of 117 patients with COVID-19 at the City General Hospital 8th September, Skopje. SaO2 and radiological findings were analyzed as dependent variables. COVID-19 symptoms (e.g., increased temperature, dyspnea, cough, shortness of breath, severe general condition), and laboratory markers were retrospectively obtained from medical records. Each COVID-19 symptom was dichotomously registered (0=absent, 1= present). We analyzed C-reactive protein (CRP), lactate dehydrogenase (LDH), and D-dimmers as laboratory markers. SaO2 was measured by pulse oximeter. Radiological findings were classified (1=normal finding, 2=peripheral opacities, and 3=consolidations). Series of regression models were tested to examine associations of symptoms and laboratory markers to SaO2 and radiological findings, controlling for age, gender, and number of identified co-morbidities. Results: SaO2 was negatively predicted by either LDH (β = -0.664, p < 0.001) and D-dimmers (β = -0.181, p < 0.05) (R2 for the model = 0.549), or shortness of breath (β = -0.201, p < 0.05) and severe general condition (β = -0.345, p < 0.01) (R2 for the model = 0.25). Severe general condition (β = 0.28, p < 0.01) predicted more progressed radiological findings (R2 for the model = 0.175). Conclusion: Certain symptoms and laboratory markers, especially LDH and D-dimmers have to be taken into consideration in hospitalized patients with COVID-19 infection.