Association Between Acute Gastrointestinal Injury and Mortality Risk in Critically Ill Patients: A Systematic Review and Meta-Analysis

OBJECTIVE: To systematically evaluate the association between severe AGI/GI dysfunction score (GIDS) and mortality risk in adult ICU patients. METHODS: We conducted a systematic review and meta-analysis. We searched the MEDLINE, Embase, Web of Science and Cochrane Central Register of Controlled Trials databases for articles published between January 2016 and January 2025. Observational cohort studies reporting mortality outcomes in ICU patients with AGI (grades III-IV vs 0-II) or GIDS (scores 2-4 vs 0-1) were included. Studies focusing on specific subpopulations such as patients following cardiac surgery or with COVID-19 were excluded to maintain population homogeneity. The primary outcome was short-term all-cause mortality. Random-effects meta-analysis using inverse-variance weighting was performed using odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: Eight studies involving 2,786 critically ill patients were included. The pooled analysis demonstrated that severe GI dysfunction (AGI III-IV or GIDS 2-4) was significantly associated with increased mortality risk (OR 2.78, 95% CI 2.19-3.52, I2=42.5%). Subgroup analyses by outcome type (28-day/ICU mortality: OR 2.70, 95% CI 2.04-3.58; in-hospital mortality: OR 4.27, 95% CI 1.63-11.18) and scoring system (AGI: OR 2.75, 95% CI 2.07-3.67; GIDS: OR 3.18, 95% CI 1.43-7.07) showed consistent results. The addition of a large-scale prospective Chinese study (Wang 2024, n=1,102) and a multicentre European cohort (Reintam Blaser 2021, n=540) strengthened the findings and broadened generalisability. CONCLUSIONS: Severe AGI is strongly associated with increased mortality in critically ill patients. Early recognition and assessment of GI dysfunction using standardised grading systems may facilitate risk stratification and guide clinical management.