Abstract: Objective To explore the risk factors for death during plasma exchange therapy for subacute and acute liver failure (ACLF) based on propensity score matching method (PSM). Methods The clinical data of 196 patients with ACLF admitted to our hospital from January 2019 to January 2023 were analyzed. According to the death situation during plasma exchange therapy, they were divided into death group (n=68) and survival group (n=128). A 1:1 PSM method was used to match general demographic variables between the two groups; after matching, Cox regression model was applied to analyze the factors influencing mortality during ACLF plasma exchange treatment. Kaplan-Meier curve was drawn to analyze the relationship between influencing factors and death during ACLF plasma exchange. Results The mortality rate during ACLF plasma exchange treatment was 34.69%. Before matching, there were no statistically significant differences between the two groups in terms of gender, BMI, smoking history, hypertension, hyperlipidemia, diabetes, and chronic kidney disease (P>0.05). There were significant differences in age and drinking history (P<0.05). After PSM, 64 pairs were successfully matched, and there were no significant differences in all matched factors between the two groups (P>0.05), indicating good balance and effective matching. After matching, the ratio of the death group with hepatorenal syndrome, the model of end-stage liver disease (MELD) score system combined with serum sodium (MELD-NA) score, red blood cell volume distribution width (RDW), total bilirubin (TBil), blood creatinine (Scr) and international standardized ratio (INR) were higher than those of the survival group (P<0.05). The levels of serum sodium and prothrombin activity (PTA) and the proportion of treatment compliance were lower than those of survival group (P<0.05). Cox regression analysis revealed that MELD-Na scores (HR=2.450, 95% CI:1.483~4.046), concurrent hepatorenal syndrome (HR=2.223, 95% CI:1.496~3.303), RDW (HR=2.912, 95% CI:1.416~5.991), PTA (HR=0.373, 95% CI:0.225~0.620), and treatment compliance (HR=0.284, 95% CI:0.141~0.571) were significant factors affecting mortality during ACLF plasma exchange treatment (P<0.05). Cox regression model after adjusting for confounders showed that MELD-Na score (HR=2.889, 95% CI:1.431~5.836), hepatorenal syndrome (HR=3.048, 95% CI:1.332~6.975), RDW (HR=2.166, 95% CI:1.340~3.502) were the influential factors of death during ACLF plasma exchange (P<0.05). Log-rank test showed that the mortality of patients with high MELD-Na score, hepatorenal syndrome and high RDW were higher than those of patients with low MELD-Na score, no hepatorenal syndrome and low RDW (P<0.05). Conclusion Based on PSM, MELD-Na score, hepatorenal syndrome, RDW are found to be influential factors for death during ACLF plasma exchange treatment.

Key words: Subacute and acute liver failure, Plasma exchange, Death Risk factors, Propensity score matching method