Tocilizumab in ICU-admitted COVID-19 Patients: A Retrospective Study.

Background:Severe and critically-ill COVID-19 patients are characterized by a severe inflammatory response. Pharmacologic inhibition of acute-phase inflammatory pathways such as IL-6 receptor inhibitor, Tocilizumab (TCZ) may improve patient outcomes in these cases. Consequently, the therapeutic benefit of TCZ was evaluated in this study. Methods:We evaluated intravenous tocilizumab in severe and critically ill adult COVID-19 patients who met pre-defined stringent CRS criteria. A single-center, prospective, observational cohort study was carried out among consecutive adult (≥18 years of age) in-patients with COVID-19 between March 20, 2020 and March 20, 2021. In total, 354 patients were included in our study. Mortality and time to hospital discharge were compared between patients who received tocilizumab treatment (n = 177) and those who did not (n = 177). Results:A total of 354 patients were analyzed whereas 177 patients were included in each group. In those receiving TCZ, all-cause mortality was significantly reduced, corresponding to an adjusted hazard ratio (HR) of 0.57, (95% confidence interval (CI): 0.43-0.76; P < 0.001). Furthermore, time to discharge was significantly improved in the TCZ group (HR: 1.66; 95%CI: 1.17-2.36, P = 0.004). Invasive mechanical ventilation was not statistically different among the study groups after adjusting for confounding variables (HR: 1.38; 95%CI: 0.89-2.14; P = 0.139). Dosing frequency was independent of survival status (P = 0.676). Conclusion:The use of TCZ in ICU-hospitalized patients resulted in improved patient survival and reduced duration of hospitalization. Further studies are needed to confirm the efficacy of TCZ in severe and critical COVID-19 cases.