Association between pulse pressure levels and mortality in patients with septic shock: a retrospective cohort study

Research on the impact of Pulse Pressure (PP) levels on Septic Shock patient prognosis is relatively limited. This study aims to analyze data from septic shock patients to investigate the prognostic effects of maintaining different PP levels during the early resuscitation phase.

Data were extracted from the MIMIC-IV 3.1 database and septic shock patients meeting inclusion and exclusion criteria were collected from the Second Department of Critical Care Medicine at the Second Affiliated Hospital of Anhui Medical University. Patient information was gathered, and the average PP over the first 24 h in the ICU (PP_{24 h} ) was calculated. The optimal PP cutoff points were determined using X-tile software, and patients were divided into three groups based on PP_{24 h} . Propensity score matching (PSM) was applied to adjust for confounding factors, and results outcomes were compared across groups. Subgroup analyses explored variations in results among different populations, and multivariate logistic regression further assessed the relationship between PP and outcomes. Finally, local data were used for generalizability assessment of the primary findings on 28-day mortality.

PP_24h maintained within 40-70 mmHg exhibited significantly higher survival rates. Subgroup analysis suggested that age significantly influenced the PP-mortality relationship: among elderly patients (>65 years), PP_24h > 70 mmHg was associated with the highest mortality risk, whereas in younger patients (≤65 years), PP_24h < 40 mmHg posed the greatest risk. Univariate and multivariate logistic regression confirmed that PP_24h > 70 mmHg or < 40 mmHg were independent risk factors for 28-day mortality in septic shock patients.

In our study, maintaining PP levels between 40 and 70 mmHg during early resuscitation was associated with significantly lower 28-day mortality in septic shock patients. Our exploratory findings suggest that hemodynamic management strategies might need to consider patient age. Future studies are needed to investigate whether targeting an upper PP limit in elderly patients or avoiding low PP in younger patients could improve outcomes.