Crush injury syndrome in earthquakes: a systematic review and meta-analysis on its frequency and complications

BACKGROUND: Crush syndrome is a life-threatening systemic complication of traumatic rhabdomyolysis and a leading cause of morbidity and mortality following earthquakes. Despite its clinical significance, a comprehensive synthesis of its global epidemiology, management, and outcomes is lacking. This systematic review and meta-analysis aimed to consolidate the evidence on CS in earthquake victims. METHODS: We conducted a systematic review in accordance with PRISMA guidelines (PROSPERO: CRD420251177534). Electronic databases (PubMed/MEDLINE, Web of Science, CINAHL) were searched from inception through January 2024 for observational studies of earthquake casualties with CS. Outcomes included mortality, dialysis requirement, acute kidney injury (AKI), and other complications. Data were pooled using random-effects meta-analysis. RESULTS: Fifty studies (1988-2023), primarily from Turkey, Iran, and China, were included. Substantial heterogeneity was observed, largely due to inconsistent definitions of CS. The pooled proportion of patients requiring dialysis was 0.49 (95% CI 0.40-0.58; I²=96.95%, 38 studies). The overall pooled mortality was 0.08 (95% CI 0.06-0.10; I²=93.0%, 39 studies), with significant regional variation (1% to 26%). AKI was the most frequent complication (pooled proportion 0.49; 95% CI 0.38-0.59). Marked creatine kinase elevation and metabolic derangements were consistently reported. CONCLUSIONS: CS following earthquakes carries a high burden of renal failure, with nearly half of affected patients requiring dialysis. Mortality is significant and influenced by geographic context and response capabilities. The profound heterogeneity in definitions and reported outcomes underscores an urgent need for standardized diagnostic criteria. Preparedness planning must prioritize early volume resuscitation, surge capacity for renal replacement therapy, and the development of context-adapted, evidence-based clinical guidelines.