Acute gastrointestinal injury severity assessment informs nutritional support and prognostic evaluation in critically ill children: a narrative review

Acute gastrointestinal injury (AGI) affects 41–65% of children admitted to pediatric intensive care units (PICUs) and is associated with prolonged mechanical ventilation, extended hospital stays, multiple organ dysfunction, and increased mortality. Although the 2012 European Society of Intensive Care Medicine (ESICM) AGI grading system provides standardized gastrointestinal assessment for adults, no validated pediatric-specific tool currently exists. This narrative review critically synthesizes the prognostic and nutritional relevance of AGI severity assessment in critically ill children. A structured literature search of PubMed, Embase, Web of Science, Google Scholar, Cochrane Library, CINAHL, CNKI, and Wanfang Data through December 2025 yielded 78 peer-reviewed articles, guidelines, and consensus statements. Two reviewers independently screened records; evidence was appraised narratively with explicit attention to study design and methodological quality, assigning greater weight to multicenter prospective studies, pediatric guidelines, and meta-analyses (level I–II evidence). No formal quality assessment, consensus methodology, or systematic evidence synthesis was performed, consistent with narrative review methodology. Existing pediatric adaptations of adult AGI criteria have been reported in single-center and observational studies and include reported thresholds for gastric residual volume (>5 mL/kg), intra-abdominal pressure gradations, and feeding intolerance definitions. Higher AGI severity is consistently associated with increased mortality, prolonged mechanical ventilation, and greater multiple organ dysfunction syndrome. Synthesis of AGI severity concepts with pediatric nutrition guidelines suggests that early enteral nutrition appears feasible in mild dysfunction, whereas severe grades may warrant cautious parenteral supplementation with dynamic reassessment. This review identifies critical gaps: the absence of multicenter validation, the subjective nature of grading variables, and the lack of age-stratified nutritional trials. In conclusion, AGI severity assessment holds conceptual promise for risk stratification and nutritional guidance in pediatric intensive care, but requires formal consensus methodology, systematic evidence synthesis, and prospective validation before clinical adoption.