Timing of administration of Tocilizumab and its effect on outcome in critically ill COVID-19 patients. A retrospective study

Abstract

Background: COVID-19 infection has been implicated in millions of deaths worldwide. The respiratory distress occurs with cytokine storm around 2ndweek of symptom onset. Tocilizumab, a humanized monoclonal antibody directed against the interleukin 6(IL-6) receptor has been used at varying extents in suppressing it, however, limited literature exists about the timing of its administration. We contemplated this study with the primary objective to establish whether tocilizumab favourably affected the outcome when given in the early stages of complication. The secondary objectives were to assess the importance of ROX score and the effect of age on outcome. Methods: We conducted a retrospective study in a tertiary care hospital. Patients who received tocilizumab were divided into two groups depending on whether they received the drug in ≤ 10 days (Group 1) or≥ 11 days (Group 2) of onset of symptoms. The patient’s demographic data and co-morbidities, on- admission vitals, ROX score, and laboratory parameters, outcome etc. were collected from the electronic health records. Results: Both groups were comparable with regard to demographic and baseline parameters on admission. The outcome was significantly better in patients of Group-1(P=0.01) with better survival. The outcome was also significantly higher in ages ≤ 50yrs age(P=0.02) who received tocilizumab. Failure to improve ROX score after 24hrs. of administration of tocilizumab was associated with poor outcomes (p=0.001). Conclusion: Tocilizumab when given in the early stages of COVID-19-related complications may be associated with decreasing mortality. Age may be an indicator of favourable effect, and failure to improve ROX score after tocilizumab is associated with poor outcomes

Keywords

• covid-19،covid-19-mortality
• cytokine storm syndrome
• tocilizumab
• rox score