The Value of Interleukin-6 among Several Inflammatory Markers as a Predictor of Respiratory Failure in COVID-19 Patients

Background: The severe acute respiratory syndrome coronavirus, often known as SARS-CoV-2, can lead to severe pneumonia and hypoxia. Some studies have shown that interleukin-6 (IL-6) can indicate respiratory failure in COVID-19 patients. Aim of the work: To determine if the laboratory marker IL-6 has the ability to predict respiratory worsening in COVID-19 patients three days after hospital admission. Patients and Methods: The last 100 consecutive COVID-19-infected individuals as determined by a positive reverse transcription real-time polymerase chain reaction (rt RT-PCR) test of their respiratory tract swabs were included in this retrospective study. Patients were separated into two groups based on the highest FiO2 they needed in the first three days after admission; group with low FiO2 and group with high FiO2. Results: In comparison to the low FiO2 group, the high FiO2 group had considerably greater serum IL-6 levels. In comparison to the low FiO2 group, the non-survivors percentage was much higher in the high FiO2 group. Additionally, in both low and high FiO2 groups, serum IL-6 was considerably lower in survivors compared to non-survivors. According to ROC curve, IL-6 displayed an AUC of 0.82 with a strong significance at cutoff value of 41.2 pg/mL. Sensitivity, specificity, PPV and NPV were 88.2%, 79.8%, 52.2% and 96.4% respectively. Conclusion: In COVID-19 patients who have been admitted to the hospital, serum IL-6 is a potent indicator of early respiratory failure. Elevated IL-6 levels are linked to mortality and the requirement for mechanical ventilation (MV).