Aim There are few reports on the prognostic factors associated with mortality in coronavirus disease (COVID-19) patients with critical disease. This study assessed prognostic factors associated with mortality of patients with critical COVID-19 who required ventilator management. Methods This single-center, retrospective cohort study used medical record data of COVID-19 patients admitted to an emergency ICU at a hospital in Japan between March 1, 2020 and September 30, 2021, and provided with ventilator management. Multivariable logistic regression was used to identify factors associated with mortality. Results Seventy patients were included, of whom 29 (41.4%) died. The patients who died were significantly older (median: 69 years) (interquartile range [IQR]: 47-82 years) than the patients who survived (62 years [38-84 years], p<0.007). In addition, patients who died were significantly less likely to have received steroid therapy than patients who survived (25 [86.2%] vs. 41 [100%], p=0.026). In the multivariable analysis, age was identified as a significant prognostic factor for mortality and the risk of death increased by 6% for every one-year increase in age (OR: 1.06; 95% CI: 1.00-1.13; p=0.048). Medical history was not a risk factor for death. Conclusion Age was a predictor of mortality in critically ill patients with COVID-19. Therefore, the indications for critical care in older patients with COVID-19 should be carefully considered.

Introduction: This study aimed to determine if tocilizumab treatment for coronavirus disease 2019 (COVID-19) increases bacteremia and suppresses fever and inflammatory reactants. Methods: In this single-center, retrospective, observational study, all patients with COVID-19 admitted to our emergency intensive care unit from March 2020 to August 2021 were categorized into tocilizumab-treated and tocilizumabnaı ¨ve groups, and the incidence of bacteremia and other factors between the two groups were compared. Patients with bacteremia were further classified into tocilizumab-treated and tocilizumab-naı ¨ve groups to determine if fever and inflammatory reactants were suppressed. Results: Overall, 144 patients were included in the study, 51 of whom received tocilizumab, which was administered on the day of admission. Further, of the 24 (16.7%) patients with bacteremia, 13 were in the tocilizumab-treated group. Results revealed a significant difference in the C-reactive protein level (p \ 0.001) at the onset of bacteremia between the tocilizumabtreated group [median 0.42 mg/dL (0.27-0.44 mg/dL)] and the tocilizumab-naı ¨ve group [7.48 mg/dL (4.56-13.9 mg/dL)]. The median number of days from admission to onset of bacteremia was not significantly different between the tocilizumab-treated group [10 days (9-12 days)] and the tocilizumab-naı ¨ve group [9 days (7.5-11 days)] (p = 0.48). There was no significant difference in fever between the groups. Multivariate logistic analysis showed that tocilizumab treatment did not affect the probability of bacteremia. Conclusion: Treatmentof patients with COVID-19 with tocilizumab does not increase the risk of bacteremia. Tocilizumab suppresses C-reactive protein levels but not fever. Therefore, careful monitoring of fever can reduce the risk of missed bacteremia.