Abstract
OBJECTIVE: To explore the optimal range of blood pressure (BP) in elderly sepsis patients. METHODS: A retrospective cohort study was conducted using data from the Medical Information Mart for Intensive Care-IV (MIMIC-IV). Restricted cubic spline (RCS) analysis was employed to examine and visualize the nonlinear relationship between BP and the incidences of in-hospital mortality and atrial fibrillation. Optimal systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) ranges were identified, and their association with 28-day mortality was validated using Cox regression analysis, propensity score matching (PSM), inverse probability weighting (IPTW), doubly robust model estimation (DR), and Kaplan–Meier survival curves (K-M). RESULTS: A total of 2,253 patients were included. RCS analysis revealed an L-shaped relationship between BP and in-hospital mortality, while the risk of atrial fibrillation increased above certain upper limits. The optimal SBP, DBP and MAP ranges were 108–118, 51–57, and 69–74 mmHg, respectively. Further statistical models confirmed that patients within the optimal BP range were associated with lower 28-day mortality. K–M survival analysis demonstrated that patients within the optimal BP range had a higher probability of survival (All Log-Rank P < 0.05). CONCLUSIONS: This single-center study suggests an optimal BP range for elderly sepsis patients that is associated with reduced 28-day mortality. These findings point to a potential optimal range for hemodynamic management in this population and warrant validation in prospective, multi-center studies. CLINICAL TRIAL: Not applicable. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12879-025-12255-w.