Paediatric trauma mortality at a level 1 trauma centre: a retrospective case series at Karolinska University Hospital, Stockholm.

Paediatric trauma mortality is uncommon in well-resourced systems, limiting clinical exposure and necessitating system-level learning through detailed review of individual deaths. This retrospective descriptive case series characterises paediatric trauma deaths following trauma-call activation at Karolinska University Hospital (KUH), Stockholm, Sweden's primary level 1 trauma centre, between 2016 and 2025. Eligible cases were patients aged 0-17 years who triggered trauma-team activation, were entered into the Karolinska Trauma Registry, and died within 30 days of injury.Among 1,792 paediatric trauma-call activations, 28 patients died, corresponding to a 30-day case fatality rate of 1.6% among activated trauma patients. The cohort comprised 16 males and 12 females (median age 15), and critical injury severity (New Injury Severity Score [NISS] ≥ 25) was observed in 25 of 26 cases.Penetrating trauma accounted for most deaths (15/28), mainly stabbings and gunshot wounds; assault was recorded in half of cases, and prehospital cardiac arrest occurred in 17 patients. Isolated head injury was the most common injury pattern (12/28, 42.9%), followed by thoracoabdominal injury (4/28, 14.3%). The leading recorded causes of death were haemorrhagic shock (14/28, 50.0%) and traumatic brain injury (12/28, 42.9%); cause of death was unavailable in 2 cases (7.1%).Fatal paediatric trauma following trauma-call activation was rare but characterised by severe injury and a substantial burden of violence-related penetrating trauma. The reported case fatality rate applies only to trauma-call activations captured in the registry and should not be interpreted as mortality among all injured children in the region. Detailed case-level review may support clinical audit, service evaluation, and prevention strategies targeting interpersonal violence among children and adolescents.