The Role of Serial Monitoring of Laboratory Parameters in Determining the Need for Intensive Care in Severe COVID-19: A Single-Center Retrospective Study

Objective: Laboratory parameters play a critical role in monitoring and prognosticating coronavirus disease 2019 (COVID-19). However, there is limited research regarding the role of serial laboratory parameter monitoring in forecasting prognosis. This study aimed to investigate the trend of serial serum biomarker monitoring in patients with severe COVID-19 and determine its role in predicting the need for intensive care. Materials and Methods: This retrospective single-center study included all patients aged 18 years and older diagnosed with severe COVID-19 and hospitalized between March 1 and November 30, 2021. Serial laboratory measurements - including lymphocyte count, platelet (PLT) count, C-reactive protein (CRP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), D-dimer, ferritin, lactate dehydrogenase (LDH), and troponin I - were recorded on days 0, 2, 4, 6, and 8 from ward admission to intensive care unit (ICU) transfer. Patients who required ICU were compared to those who did not, regarding demographics, clinical features, and serial laboratory measurements. Receiver-operating characteristic (ROC) curves were generated for each serial laboratory parameter to assess its predictive value for ICU admission, and the area under the curve (AUC) was calculated. Results: A total of 773 patients were included, of whom 20.1% required ICU care. Significant differences were observed between the two groups in lymphocyte count, PLT, and troponin I across all measurements. CRP, D-dimer, and LDH showed significant differences between the groups on days 2, 4, 6, and 8. The AUC values of lymphocyte count, PLT, CRP, LDH, and troponin I increased in a time-dependent manner from day 0 to day 8, with an observed increase in statistical significance. Conclusion: Dynamic monitoring of lymphocyte count, PLT, CRP, LDH, and troponin I was found to be valuable in predicting poor outcomes related to COVID-19. We believe that our study can assist clinicians in predicting ICU needs in patients with severe COVID-19 through widely accessible laboratory tests.