Clinical Scoring Systems for Blunt Abdominal Trauma: A Narrative Review of the Clinical Abdominal Scoring System in Resource-Variable Settings.

BACKGROUND: Blunt abdominal trauma (BAT) causes significant preventable deaths worldwide, with death rates 2-5 times higher in low- and middle-income countries (LMICs). Focused assessment with sonography for trauma (FAST) is standard but limited by operator skill and poor detection of certain injuries. The clinical abdominal scoring system (CASS), a simple bedside tool, could aid in quick risk assessment in low-resource areas, but needs thorough review. The objective of this review is to synthesize evidence on the diagnostic accuracy, clinical value, and practical use of CASS in BAT care, focusing on varied resource settings. METHODS: We searched PubMed, Scopus, Web of Science, Cochrane Library, and Google Scholar from January 2011 to October 2025 for studies using CASS in adult BAT. Relevant articles were selected based on predefined criteria, quality was assessed using QUADAS-2 and CASP tools, and findings were narratively summarized due to study differences. RESULTS: Six CASS studies (n = 1510 patients) showed sensitivity of 80%-100% (median 90%) and specificity of 60%-88% (median 74%) for predicting surgery in BAT. CASS plus FAST reached an AUC of 0.94. Practical use reduced decision time by 60% and CT scans by 57%. Limitations included single-site studies, Asian focus, and no patient outcome data, with over-triage risks of 12%-40%. CONCLUSIONS: CASS offers good sensitivity for BAT triage in low-resource areas but needs broader testing in diverse groups. It works best alongside other tools in stepwise protocols but not alone. Future work should validate this scoring system in LMICs, assess long-term outcomes, and evaluate costs.