Association between intravenous magnesium sulfate and mortality in patients with sepsis-associated liver injury: a retrospective cohort study

Background Sepsis-associated liver injury (SALI) is a significant risk factor for mortality in patients with sepsis. Magnesium, as an essential electrolyte, has a correlation with adverse outcomes in critical illness when deficient, yet the therapeutic efficacy of magnesium sulfate in SALI remains undetermined. This study was designed to evaluate the association between magnesium sulfate therapy and prognosis in SALI patients. Method This retrospective cohort study utilized data from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, with the primary endpoint being 30-day all-cause mortality. Propensity score matching (PSM) achieved covariate balance, Kaplan-Meier survival curves and Cox regression were employed to analyze the magnesium sulfate-mortality relationship in SALI patients. The study results were externally validated using the eICU 2.0 database. Result The present study was conducted on 648 SALI patients. After PSM, the 30-day all-cause mortality rate was significantly reduced in the magnesium sulfate group versus the non-magnesium sulfate group (30.4% vs. 44.6%, P = 0.002). Kaplan-Meier survival analysis demonstrated superior 30-day cumulative survival rates in the magnesium sulfate group after PSM ( P < 0.001). Both multivariable Cox regression (HR, 0.62, 95% CI, 0.47–0.82, P < 0.001) and inverse probability weighting (IPW) analysis (HR, 0.69, 95% CI, 0.53–0.89, P = 0.005) indicated that magnesium sulfate treatment was an independent protective factor for 30-day all-cause mortality risk. Conclusion The use of magnesium sulfate is associated with a reduction in all-cause mortality among SALI patients. Future research should consider individual patient variations to explore its true effectiveness.