Efficacy of tocilizumab in critically ill COVID-19 patients: a retrospective cohort

Background & Objective: Covid-19 is a complex disease with unpredictable blended pattern, and it resembles the cytokine release syndrome (CRS), marked with vasculopathy, coagulopathy, ARDS, multi-organ failure, and aggressive rise of inflammation markers in the serum. Tocilizumab (TCZ) has been in use as an off-label drug due to its antagonist activity on IL-6 receptor. This study compared the efficacy of standard of care (SOC), and SOC along with TCZ, in critically ill COVID-19 patients. Methodology: In this retrospective cohort, we included 74 critically ill COVID-19 patients, aged between 18 to 90 y. Those who received only SOC were placed in the SOC group, while patients who received TCZ in addition to SOC, were placed in the TCZ + SOC group. The SOC included low molecular weight heparin (LMWH) 60 mg S/C OD, dexamethasone 6 mg IV OD, remdesivir (antiviral) 200 mg IV stat then 100 mg IV OD for 5 days and when needed 10 days, antibiotics for secondary infection e.g., Azithromycin 500 mg IV OD, in the presence of High flow Oxygen (HFO) or CPAP. X-rays chest, serum levels of lactate dehydrogenase (LDH), D-Dimers, ferritin, pro-BNP, C-reactive protein (CRP), total leukocyte count (TLC), renal and liver markers, serum electrolytes, sugar levels, and ABGs were obtained from the data, at the time of admission in ICU and on the 7th day of ICU stay. Results: 57% patients received only SOC while 43% received TCZ in addition to SOC. Improvement in hypoxia and radiological findings on day-7 was more in SOC' group than TCZ+ SOC' group (52% vs. 34% and 52% vs. 31% respectively), but it was not statistically significant. Overall improvement in inflammation markers on day-7 was similar in both groups with p = 0.925. Survival was 45% vs. 37.5% in SOC' vs. TCZ+ SOC' group respectively (p = 0.504). Conclusion: Tocilizumab does not alter the overall survival of critically ill COVD-19 patients. Key words: COVID-19; Tocilizumab; Standard of care; Efficacy; Survival Abbreviations: TCZ – Tocilizumab; HFO - High flow Oxygen; LDH - lactate dehydrogenase; CRS - cytokine release syndrome; CRP - C-reactive protein; SOC - standard of care; LMWH - low molecular weight heparin; COVID-19 - Coronavirus Disease 2019; SARS-CoV-2 - Severe Acute Respiratory Syndrome Coronavirus 2 Citation: Sadaf S, Bashir B, Haider SS, Mustafa G, Naqvi SAA. Efficacy of tocilizumab in critically ill COVID-19 patients: a retrospective cohort. Anaesth. pain intensive care 2021;25(3):__. DOI: doi.org/10.35975/apic.v25i3.1520 Received: January 8, 2021; Reviewed: March 11, 2021; Accepted: March 11, 2021