Publication date: Jun 01, 2026
BackgroundSevere or critical coronavirus disease 2019 pneumonia is associated with a high mortality rate and considerable treatment cost. Although a few reports have shown that N-acetylcysteine may shorten recovery time in patients with severe acute respiratory syndrome coronavirus 2 infection, its effect on mortality or disease progression in patients with severe or critical coronavirus disease 2019 pneumonia has not been investigated. This study aimed to evaluate the effect of N-acetylcysteine on mortality or disease progression, hospital stay, and hospitalization costs in patients with severe or critical coronavirus disease 2019 pneumonia. MethodsThis single-center, retrospective cohort study included 221 patients with severe or critical coronavirus disease 2019 pneumonia who were hospitalized at the Department of Respiratory and Critical Care Medicine, Huashan Hospital from December 2022 to January 2023. After 1:1 propensity score matching, 176 patients were divided into two groups based on whether oral N-acetylcysteine was administered for at least 3 days. Binary logistic regression was used to analyze the effect of N-acetylcysteine on mortality or disease progression, whereas its effect on 28- or 90-day mortality was analyzed using Cox regression. ResultsBinary logistic regression analysis showed that N-acetylcysteine was associated with a reduced risk of the composite endpoint of mortality or disease progression during hospitalization (odds ratio = 0. 288, 95% confidence interval: 0. 147-0. 793, p = 0. 011). However, N-acetylcysteine was not significantly associated with hospitalization costs, length of hospital stay, or the use of high-flow oxygen or mechanical ventilation. In addition, no significant association was observed between N-acetylcysteine use and 28- or 90-day mortality. Given the retrospective design and potential residual confounding, these findings should be interpreted as exploratory. ConclusionsIn this retrospective cohort study, treatment with N-acetylcysteine for at least 3 days was associated with a possible reduction in mortality or disease progression during hospitalization in patients with severe or critical coronavirus disease 2019 pneumonia. Prospective studies are needed to confirm these observations.
