Effect of time intervals in critical care provided by helicopter emergency medical services on 30-day survival after trauma

Background: Trauma is the leading cause of death especially in children and young adults. Prehospital care following trauma emphasizes swift transport to a hospital following initial care. Previous studies have shown conflicting results regarding the effect of time on the survival following major trauma. In our study we investigated the effect of prehospital time-intervals on 30-day mortality on trauma patients that received prehospital critical care. Methods: We performed a retrospective study on all trauma patients encountered by helicopter emergency medical services in Finland from 2012 to 2018. Patients discharge diagnoses were classed into (1) trauma without traumatic brain injury, (2) isolated traumatic brain injury and (3) trauma with traumatic brain injury. Emergency medical services response time, helicopter emergency medical services response time, on-scene time and transport time were used as time-intervals and age, Glasgow coma scale, hypotension, need for prehospital airway intervention and ICD-10 based Injury Severity Score were used as variables in logistic regression analysis. Results Mortality data was available for 4,803 trauma cases. The combined 30-day mortality was 12.1% (582/4,803). Patients with trauma without a traumatic brain injury had the lowest mortality, at 4.3% (111/2,605), whereas isolated traumatic brain injury had the highest, at 22.9% (435/1,903). Patients with both trauma and a traumatic brain injury had a mortality of 12.2% (36/295). Following adjustments, no association was observed between time intervals and 30-day mortality. Discussion Our study revealed no significant association between different timespans and mortality following severe trauma in general. Trends in odds ratios can be interpreted to favor more expedited care, however, no statistical significance was observed. As trauma forms a heterogenous patient group, specific subgroups might require different approaches regarding the prehospital timeframes. Study type prognostic/therapeutic/diagnostic test.