Single versus multiple doses of Tocilizumab in critically ill patients with coronavirus disease 2019 (COVID-19): A two-center, retrospective cohort study.

Purpose: To evaluate the effectiveness and safety of the optimal tocilizumab dosing regimen.

Methods: A two-center, retrospective cohort study, for COVID19 critically ill patients admitted to the intensive care units (ICUs). We included critically ill patients aged 18 years or older who received tocilizumab during ICU stay.