Abstract
BACKGROUND: Emergency ultrasound, particularly extended Focused Assessment with Sonography in Trauma (eFAST), is increasingly recognised as essential in undergraduate medical education. Although blended learning offers flexibility, its effect on practical skills remains uncertain. This randomised controlled trial examined whether supplementing voluntary handheld ultrasound practice with digital self-study improved eFAST performance compared with digital preparation alone. METHODS: In this randomised controlled trial, 173 medical students were allocated to a control group (digital self-study; n = 89) or an intervention group (digital self-study plus voluntary handheld ultrasound practice; n = 84). All the students performed a standardised eFAST on a high-fidelity simulator. A blinded rater assessed performance using a modified Objective Structured Assessment of Ultrasound Skills (OSAUS) score (primary outcome). The secondary outcomes were examination duration, complete eFAST achievement, and student feedback. Regression analyses adjusted for potential confounders. RESULTS: The intervention group achieved a significantly higher modified OSAUS score (median 16.0 vs. 13.0, p < 0.001), completed examinations faster (median 247 vs. 370 s, p < 0.001), and more frequently performed a complete eFAST (42.9% vs. 23.6%, OR 2.43, 95% CI 1.26–4.67). Adjusted analyses confirmed these associations (OSAUS + 3.29 points; aOR for complete eFAST 2.52; HR for faster completion 4.26; all p < 0.01). Student acceptance was high; intervention participants reported longer preparation times (2.0 vs 1.0 h, p < 0.001) without additional disadvantages. CONCLUSIONS: Blended e-learning with handheld ultrasound devices significantly improved eFAST training outcomes, including higher performance scores, shorter examination times, and more complete scans. These findings support the integration of handheld ultrasound practices into the undergraduate curriculum. TRIAL REGISTRATION: Not applicable. This study did not involve a health care intervention on patients but focused on educational training in ultrasound techniques for medical students. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12909-026-09054-5.