Lactate is Associated with Long-Term Mortality in Hospitalized Patients with COVID-19: A Retrospective Cohort Study

Abstract

Introduction: A recent pandemic caused by Coronavirus 2019 (COVID-19) caused mild and severe systemic organ involvement that led to the death of enormous numbers of people. The prevalence of the disease has declined over the past years, but concerns about upcoming mutations remain. In this study, the relationship between lactate levels and mortality at different times was investigated. Methods: In the present retrospective study, 228 hospitalized patients with COVID-19 were included according to the inclusion and exclusion criteria. A modified National Early Warning Score 2 (NEWS2) was used to determine the severity of the patients' conditions. Follow-up of patients, if discharged alive, has been done from hospitalization until March, 2022. Data were analyzed using SPSS version 22, and p < 0.05 was considered significant. Results: Lactate levels (2.88 ± 2.37 in the dead group versus 1.68 ± 1.33 in the living group) have a significant relationship with mortality at hospitalization (p < 0.001). Furthermore, higher lactate levels during hospitalization (p < 0.001, HR = 2.960, 95%CI =4.255-2.58) and follow-up (p < 0.001, HR = 2.960, 95%CI =4.255 to 2.58) increased the mortality risk ratio by more than two-fold. Conclusion: This study reported that initial lactate levels at admission predict COVID-19 patients' mortality at hospitalization and follow-up. However, further research is needed in this area