Tocilizumab shortens time on mechanical ventilation and length of hospital stay in patients with severe COVID-19: a retrospective cohort study

Abstract

Background Hyperinflammation is a key feature of the pathogenesis of COVID-19 with a central role of the interleukin-6 pathway. We aimed to study the impact of the IL-6 receptor antagonist tocilizumab on the outcome of patients admitted to the intensive care unit (ICU) with acute respiratory distress syndrome (ARDS) related to COVID-19. Methods Eighty-seven patients with confirmed SARS-CoV-2 infection and moderate to severe ARDS were included (n tocilizumab = 29, n controls = 58). A matched cohort was created using a propensity score. The primary endpoint was 30-day all-cause mortality, secondary endpoints included ventilation-free days and length of stay. Results No difference was found in 30-day all-cause mortality in patients treated with tocilizumab compared to controls (17.2% vs. 32.8%, p = 0.2; HR = 0.52 [0.19 - 1.39], p = 0.19). Ventilator-free days were 19.0 (IQR 12.5 - 20.0) versus 9 (IQR 0.0 - 18.5; p = 0.04), respectively. A higher rate of freedom from mechanical ventilation at 30 days was achieved in patients receiving tocilizumab (HR 2.83 [1.48 - 5.40], p < 0.002). Median length of stay in ICU and total length of stay were reduced by 8 and 9.5 days in patients treated with tocilizumab. Similar results were obtained in the analysis of the propensity score matched cohort. Conclusions Treatment of critically ill patients with ARDS due to COVID-19 with tocilizumab was not associated with reduced 30-day all-cause mortality, but shorter duration on ventilatory support as well as shorter overall length of stay in hospital and in ICU.