A RETROSPECTIVE COHORT STUDY ASSESSING THE EFFECTIVENESS OF TOCILIZUMAB IN IMPROVING OXYGENATION IN MODERATE TO SEVERELY ILL COVID-19 PATIENTS ADMITTED IN A TERTIARY CARE CRITICAL CARE UNIT

Abstract

Introduction:The clinical presentation of COVID-19 is highly heterogeneous-ranging from asymptomatic to severe pneumonia with respiratory\nfailure that could lead to invasive mechanical ventilation or death. It is characterised by an initial phase of viral replication followed by a second\nphase of host in\uf002ammatory response(hyperimmune response)-Cytokine storm- assossiated with increased production of many cytokines\nproducing longterm damage and lung \uf001brosis.Tocilizumab, a recombinant humanised monoclonal antibody of the IgG1 class is directed against\nboth the soluble and membrane-bound forms of the IL-6 receptor and may be considered as a promising treatment modality in \uf001ghting with\ncytokine storm of COVID 19 infection.Considering the scarcity of knowledge about this new pandemic situation and the course of the disease, we\nconducted this study with a purposes of assessing the ef\uf001cacy of Tocilizumab in COVID patients.\nMethods:This retrospective, observational, cohort study was conducted in Critical care units(CCU) in Medical College and Hospital, Kolkata\nwith a primary purpose to treat the patients. All patients were treated with the standard of care according to hospital protocol and a non-randomly\nselected subset of patients(20) also received Tocilizumab. Tocilizumab was given intravenously at 8 mg/kg bodyweight (up to a maximum of 800\nmg) in two infusions, 12 h apart and level of oxygen support during hospitalization (nasal cannula, high \uf002ow nasal oxygen cannula[HFNOC], noninvasive ventilation[NIV], invasive mechanical ventilation [IMV]) was recorded . The PaO2/FiO2 before and after giving the drug recorded and\nanalyzed .\nResults: Among all the patients who received inj Tocilizumab(65% male,35% female) 70% of patients were on BiPAP,15% on HFNC and rest 15%\non invasive mechanical ventilation. Statistical analysis comparing PaO2/FiO2 before and after receiving Tocilizumab shows non-signi\uf001cant\nchanges( p value- 0.30).\nDiscussion:Tocilizumab is not effective in improving PaO2/FiO2 ratio and thus oxygenation.Though serial monitoring of IL-6 and other\nbiomarkers were not possible and we had a small sample size due to limited time period,this study can give us a small re\uf002ection of larger picture.\nConclusion-Tocilizumab is not an effective treatment modality in improving oxygenation status of moderate to severe COVID infected patients.