Association between prognostic nutritional index and mortality in patients with sepsis-associated delirium: a retrospective cohort study using the MIMIC-IV database
摘要
Patients with sepsis-associated delirium (SAD) exhibit poor prognosis and elevated mortality risk. As a comprehensive indicator reflecting nutritional status and inflammatory responses, the prognostic significance of the prognostic nutritional index (PNI) in patients with SAD has not been fully elucidated. This investigation aimed to examine the relationship between PNI values and all-cause mortality risk in SAD patients.
MethodsA retrospective analysis of data from SAD patients in the MIMIC-IV database was conducted, with 28-day all-cause mortality as the primary endpoint. Additional assessments included 90-day, 365-day, in-hospital, and ICU mortality. Kaplan-Meier curves, the log-rank test, and multivariate Cox proportional hazards regression models were used to examine the relationship between PNI and prognosis. Subgroup analysis was performed to assess the robustness of the results. Moreover, RCS models were employed to assess the presence of a linear relationship between PNI and mortality risk.
ResultsAnalysis incorporated 5394 patients diagnosed with SAD. Kaplan-Meier analysis showed that the survival curves of the four PNI groups were significantly separated (P<0.001), indicating a positive correlation between PNI levels and survival probability, while lower PNI levels suggested an increased risk of mortality. Multivariate Cox regression analysis revealed that when PNI was considered as a categorical variable (quartiles), patients in the highest PNI group (Q4) had a 42% significant decrease in 28-day mortality risk compared to the lowest PNI group (Q1) (HR=0.58, 95% CI: 0.48-0.69). Protective associations were consistently observed for 90-day, 365-day, in-hospital, and ICU mortality, with all P-values less than 0.001. RCS analysis indicated a notable non-linear "L"-shaped association between PNI and mortality risk across all endpoints (P for nonlinear <0.001), showing a steep decline in mortality risk as PNI increased below 35.7645, followed by a stabilization of the protective effect beyond that threshold.
ConclusionPNI is an indicator that has an impact on patients with SAD. It can reduce their short-term and long-term mortality rates and exhibits a significant threshold effect. A PNI value <35.7645 may serve as a key clinical cutoff to identify high-risk patients with SAD and guide the initiation of nutritional interventions.