Gastrointestinal dysfunction score for mortality prediction in intensive care unit patients with pre-existing digestive system disease: a prospective observational study.

Background: Gastrointestinal (GI) dysfunction has been increasingly recognized as a common and clinically important problem in patients in the Intensive Care Unit (ICU). GI dysfunction may affect nutrition, immune function, and microbiome homeostasis, which has been associated with adverse outcomes in ICU patients. However, conventional organ failure scores such as the Sequential Organ Failure Assessment (SOFA) score do not adequately account for GI dysfunction, particularly in patients with pre-existing digestive system disease. Objective: This study aimed to evaluate the performance of the Gastrointestinal Dysfunction Score (GIDS) in adult ICU patients with pre-existing digestive system disease and to examine whether integrating GIDS with SOFA improves discrimination for 28-day mortality compared to SOFA alone. Methods: This single-center, prospective observational study included adult patients admitted to the ICU, excluding pregnancy, ICU readmission, cessation of active treatment, loss to follow-up and death within 24 h of ICU admission. Patients were stratified into GI and non-GI cohorts based on the presence of pre-existing digestive system disease at ICU admission. GIDS, SOFA and acute gastrointestinal irnjury (AGI) gades were recorded daily for the first ICU week. We compared baseline clinical characteristics and 28-day mortality between cohorts and evaluated whether adding GIDS to SOFA improved discrimination. Results: A total of 486 patients were included, with 359 in the GI cohort. Using the score of the first day in ICU, GIDS (AUC = 0.701) outperformed AGI (AUC = 0.614). When combined with SOFA, GIDS+SOFA had the highest AUC of 0.764, compared with SOFA alone (AUC = 0.739). In the GI cohort, GIDS+SOFA also demonstrated superior discrimination (AUC = 0.754) compared to SOFA alone (AUC = 0.723). Conclusion: GIDS provides a meaningful stratification of 28-day mortality risk, especially in patients with pre-existing digestive system disease. Adding GIDS to SOFA modestly improved discrimination for 28-day mortality and warrants external validation. These findings support further validation and potential incorporation of GIDS into clinical practice.