Risk factors of mortality for intensive care COVID-19 patients: A retrospective cohort study.

Abstract Aims: To identify the risk factors of mortality for coronavirus disease 19 (COVID-19) patients admitted to intensive care units (ICU), we conducted a retrospective analysis. Methods: The demographic characteristics, laboratory findings and chest X-ray data of COVID-19 patients admitted to ICU of Huoshenshan Hospital from February 10 to April 10, 2020 were retrospectively analyzed. Student's t test and chi-square test were used to compare continuous variables, categorical variables respectively. Logistic regression model was used to seek risk factors of mortality. Results: A total of 57 patients (38 males and 19 females) were included in this retrospective study, including 20 patients in deceased group and 37 patients in surviving group. Leukocyte count, neutrophil count, lymphocyte count, eosinophil count, neutrophil-to-lymphocyte ratio (NLR), urea nitrogen, lactate dehydrogenase (LDH), interleukin-6 (IL-6), C-reactive protein (CRP), arterial partial pressure of oxygen/oxygen concentration (PaO2/FiO2) and imaging findings were statistically different between the two groups. The multivariate logistic regression analysis identified IL-6 and PaO2/FiO2 as independent risk factors of mortality. The area of under curves (AUC) of IL-6 and PaO2/FiO2 were 0.9 (95%CI:0.823-0.977, p<0.0001) and 0.865 (95%CI:0.774-0.956, p<0.0001) respectively. The cut-off value of IL-6 was 25.69 pg/mL, the sensitivity was 95% and the specificity was 75.7%, while the cut-off value of PaO2/FiO2 was 167.79 mmHg, the sensitivity was 75.7% and the specificity was 85%. Conclusion: Clinicians should pay enough attention to IL-6 and PaO2/FiO2, especially when IL-6>25.69 pg/ml and PaO2/FiO2<167.79 mmHg, and take active intervention measures as early as possible.