Abstract: Objective To analyze the correlation between the peak systolic velocity (PSV) variability of superior mesenteric artery (SMA) and Gastrointestinal Dysfunction Score (GIDS) in the elderly septic patients, and to explore the predictive value of SMV-PSV variability on prognosis of the patients. Methods Sixty-six elderly septic patients admitted to Department of Critical Care Medicine, Nanjing First Hospital from October 2022 to March 2025 were enrolled in this study. The SMA-PSV values on the 1st, 2nd, 3rd day at Intensive Care Unit (ICU) were collected to calculate SMA-PSV variability. Baseline clinical data and GIDS on the 3rd and 7th day at ICU were also collected. The occurrence of feeding intolerance (FI) during enteral nutrition was recorded. The mortality rate of 28-day, ICU-free days, mechanical ventilation (MV)-free days, and continuous renal replacement therapy (CRRT)-free days were also documented. Results Patients were divided into two groups based on the median SMA-PSV variability, with 33 cases in each group. There were no statistically significant differences between the two groups in age, sex, body mass index, Acute Physiology and Chronic Health Evaluation score, Sequential Organ Failure Assessment score, SMV-PSV values from the 1st day to the 3rd day, CRRT-free days, and 28-day mortality (P>0.05). There were significant differences in GIDS on the 3rd and 7th day, ICU-free days, MV-free days, and the incidence rate of FI between the two groups (P<0.05 or P<0.01). Spearman correlation analysis showed that SMA-PSV variability was negatively correlated with GIDS on the 3rd and 7th day (r=-0.408, -0.425, all P<0.01), and positively correlated with ICU-free days and MV-free days (r=0.280, 0.267, P<0.05). Receiver operating characteristic (ROC) curve analysis indicated that the areas under the curve of SMA-PSV variability for predicting FI and 28-day mortality were 0.807 (P<0.01) and 0.731 (P<0.05), respectively. Conclusions SMA-PSV variability is associated with GIDS on the 3rd and 7th day at ICU, and could be a valuable predictor for prognosis in the elderly septic patients.

Key words: sepsis, Gastrointestinal Dysfunction Score, superior mesenteric artery, aged, peak systolic velocity, feeding intolerance